Glossary

The period in which another action potential cannot be generated even if another stimulus is applied.

The period during digestion when anabolism exceeds catabolism.

Pancreatic cells that synthesize and transport enzymes to aid in food digestion in the duodenum.

One of the two protein filaments that make up a sarcomere; thin filament.

A change in membrane potential that passes along a neuron or muscle fiber to transmit an impulse.

The movement of molecules across a cell membrane against the concentration gradient (from low concentration to high concentration), which requires the use of energy.

The presence of a hormone will further increase the effect of an already acting hormone by producing an effect of similar nature; both of these hormones can function on their own.

The principal molecule for storing and transferring energy in cells.

An enzyme that synthesizes the second messenger cAMP.

Hormone-producing glands that are located on top of the kidney. They secrete epinephrine, aldosterone, and cortisol.

[of a receptor] Membrane receptor proteins that can bind epinephrine and norepinephrine.

The cellular process of producing energy (ATP) including glycolysis, the citric acid cycle, and the electron transport system.

[of a neuron] A sensory neuron that carries information from sensory stimuli to the brain.

Small blood vessels that carry blood to the nephron.

Ability of a molecule to bind to its receptor.

The opposing pressure inside the aorta that keeps the aortic valve closed and works against the ejection of blood volume from the left ventricle.

The respiratory tract's resistance to airflow during inspiration and expiration.

A hormone that is released from the adrenal cortex in response to angiotensin II or in direct response to an increased plasma K+ concentration. It promotes Na+ reabsorption by the nephron, promoting the retention of water.

A pancreatic islet cell type that produces the hormone glucagon.

The air pressure inside the lung alveoli that varies during ventilation.

The exchange of gas between the alveoli and the atmosphere.

Retinal neurons that are involved in the photoreceptor pathway, assisting with lateral inhibition.

Contains both hydrophilic (water-loving) and hydrophobic (water-fearing) components.

A standard orientation with the body upright and hands by sides.

A potent vasoconstrictor that plays an immediate role in the regulation of blood pressure.

This enzyme is not a hormone but it is functionally important in regulating systemic blood pressure and kidney function. It enzymatically converts inactive angiotensin I to active angiotensin II.

Part of the endocrine gland and is known to produce its own hormones for secretion into systemic circulation.

A hormone that is released from the posterior pituitary gland in response to low blood pressure. ADH increases water reabsorption in the kidney, which increases blood volume, and decreases urine excretion.

A carrier protein that transports two different molecules in opposite directions across the cell membrane.

The surface of an epithelial cell that is exposed to the body cavity or the exterior surface of an organ.

Proteins that allow for the movement of water across the hydrophobic lipid bilayer membrane.

A transparent watery fluid that is in the anterior and posterior cavities of the eye. Since there is no blood supply to parts of the eye, such as the lens and cornea, the aqueous humor will provide nutrients.

Vessel that carry oxygen-rich blood away from the heart.

Smaller vessel that branches off of arteries, moving blood to capillary beds.

A type of glial cell that appears star shaped and acts to support neurons in the central nervous system. They are the most abundant cell type in the CNS.

The air pressure in the atmosphere at sea level is 760 mmHg. Lung pressures are often expressed relative to this pressure.

Adenosine 5'-triphosphate, or ATP, is the principal molecule for storing and transferring energy in cells.

A myocyte is a muscle cell, different types of myocytes can be found all around the body and even within the heart.

A peptide hormone released from the heart that promotes the excretion of water and sodium by reducing the function of ALDO, ADH, and renin.

Increased heart rate due to increased blood volume (stretch of the atria).

A cluster of spontaneously depolarizing nodal cells that are adjacent to the pulmonary artery. They transmit the electrical signal from the SA node to the bundle of His.

Smaller upper compartments of the heart which empty blood into the ventricles.

Cell signalling in which a cell secretes hormone molecules that binds to receptors on that same cell.

The ability to spontaneously depolarize.

Involuntary regulation of glands and organs in the body.

Long slender projection of a nerve cell, or neuron, that conducts electrical impulses away from the neuron's cell body or soma.

The most distal portion of a neuron's axon and is critical for neural communication. It is also referred to as the synaptic bouton and terminal bouton.

Sensory receptor cell that is sensitive to changes in pressure (detected through stretch).

The surface facing the connective tissue base to which the cell attaches (basement membrane) or the cell membrane closest to the basement membrane.

Pancreatic islet cell type that produces the hormone insulin.

An intermediate in cellular metabolism (HCO3-).

The most prominent part of bile, the salts work to help emulsify fat.

The first downstream retinal neuron from the photoreceptor. Assist in the process of transmitting the electrical signal from the photoreceptor to the RGC.

Solutes in the blood.

A barrier between circulating blood and the CNS that is highly selective, allowing nutrients and small products to reach the brain while preventing damage and infection by blocking diffusion of larger products and pathogens.

Structure that is found at the beginning of the tubular component of the nephron. The Bowman's capsule collects filtrate from the glomerulus and passes it to the proximal tubule of the kidney.

The relationship between pressure and volume. At a constant temperature, the volume of a fixed amount of gas is inversely proportional to its pressure.

Surface covered with microvilli.

A hormone produced by the parafollicular cells of the thyroid gland. Aids in the regulation of plasma calcium levels.

The active form of vitamin D.

The release of calcium from the sarcoplasmic reticulum, which is triggered by the binding of calcium to the ligand-gated channels on the sarcoplasmic reticulum.

A compound of hemoglobin and carbon dioxide, one of the forms in which carbon dioxide exists in the blood.

An enzyme present in the RBC that catalyzes the stripping of carbon dioxide from bicarbonate.

Everything that takes place between one heart beat and the next.

One of the three types of muscle tissue found in the human body. Cardiac muscle is under involuntary control and is found solely in the heart.

The amount of blood pumped through the circulatory system in 1 minute (L/min).

Cells within the heart responsible for generating force and allowing the heart to contract rhythmically.

An area within the carotid artery that contains important baroreceptors.

A type of cell membrane protein involved in facilitated diffusion and active transport of substances across the membrane.

A positively charged ion.

A network of nerves that activate the sympathetic nervous system.

Located in the brain, detect pH changes in cerebral spinal fluid.

The nerves of the brain and spinal cord.

A fold on the dorsal side of the brain. Used as a landmark, or border, of the posterior edge of the frontal lobe and an anterior edge of the parietal lobe.

A clear, colourless fluid found within the CNS which circulates nutrients and chemicals into and waste out of the brain. Additionally, it acts as a shock absorber by cushioning the brain and spinal cord.

Chemical secretions that break down small food particles into their basic nutrient components.

Sensory receptor cells that are sensitive to changes in the physiological chemical properties (ie. pH).

Brings bicarbonate into the cell to ensure that there is enough substrate to allow release of carbon dioxide.

[of a receptor] Membrane receptor proteins that can bind acetylcholine.

Constriction of the airways that interferes with normal breathing.

Partially digested/partially fluid food particles mixed with various gastric secretions.

The part of the eye that generates aqueous humor and contains the ciliary muscles. Ciliary muscles will contract to bend the lens in order to appropriately focus the eye on an object at a certain distance away.

Occurring on a twenty four hour cycle. The reason we feel like eating and sleeping at similar times of the day, even in the absence of light.

A protein which provides structural support to connective tissues, muscles, and skin.

Collects the filtrate from several nephrons for final modifications. The CD is continuous with the nephron but is not technically considered to be a part of the nephron.

The opposite of stiffness. Describes how much an object will stretch when under a given force.

The difference in the concentration of specific molecules on different sides of a cell membrane.

A type of muscle contraction in which the muscle is actively shortening.

Function of the electrical system of the heart.

The less prevalent photoreceptor in the eye that allows us to see colour and creates a sharper image. The fovea of the eye has exclusively cones.

The propagation of an action potential along an unmyelinated axon.

The ability of heart muscles, otherwise known as cardiac myocytes, to exert force by contracting.

Outcome of the electrical system of the heart, ie. conduction causes contraction.

Relating to the side of the body opposite to where the signal/organ resides. Ex. Left brain controls right limb motor movements.

Controls the body's involuntary and metabolic functions.

The transparent structure at the most anterior part of the eye. The cornea covers the entire anterior cavity of the eye and is the structure that refracts light the most.

After the release of the egg from the follicle, a corpus luteum is formed. The role of the corpus luteum varies depending on whether or not pregnancy occurred.

One out of two types of nephrons. The cortical nephron begins in the renal cortex and barely extend into the renal medulla.

The interaction between actin and myosin that occurs during muscle contraction.

A display of the inside or centre of an object by making a straight incision through the object at any angle.

Charge within the cell becomes more positive (upward slope of the curve).

The volume of air that is inhaled that does not take part in the gas exchange, because it either remains in the conducting airways or reaches alveoli that are not perfused or poorly perfused.

A minor pancreatic islet cell type that produces the hormone somatostatin.

A structure found in smooth muscle fibers that thin filaments anchor to. Dense bodies are analogous to z-lines in striated muscle.

Something that causes similar symptoms seen with diabetes.

The relaxation phase of the heart (no contraction).

Net movement from high concentration to low concentration.

A very twisted tubule that is formed by simple cuboidal epithelium, the DCT responds to hormonal signals that regulate urine composition.

Enlargement due to an increase in internal pressure.

The increased production of urine.

Any substance that promotes diuresis (the increased production of urine), which also promotes water excretion.

The “action” or “where” or “how” pathway, which is the flow of visual information from the occipital lobe to the parietal lobe. The purpose of this pathway is to determine where in space the object in sight is and how the body must move to interact with that object.

A decrease in the production of a target receptor that, in turn, causes a decrease in the body's sensitivity to a particular hormone.

A neuron in the path of the travelling signal that is further from the source than the neuron currently carrying the signal.

Swelling caused by tissue leakage.

Small blood vessels that are considered to be a part of the urinary tract. These vessels carry blood away from the glomerulus.

Female gametes.

The forcible ejection of semen from the mammalian urethra, a reflex in response to sexual stimulation.

A difference in charge across a cell membrane.

The combination of the electrical and chemical gradients across a cell membrane.

Minerals in the blood, tissues, urine, and other bodily fluids that contain an electric charge. Electrolytes balance the body’s pH levels as well as the amount of water in the body.

Process that aids in lipid digestion. Lipids are prevented from aggregating/clumping causing the hydrophobic molecules (lipids) to be evenly dispersed in a hydrophilic environment. This is because bile salts, which are amphipathic, surround the small lipid molecules.

The mixing of substances that typically do not combine easily due to their chemical properties.

The volume of blood in the ventricles following passive diastolic filling (high volume). Also referred to as preload.

The volume of blood in the ventricles that is “left over” following contraction (low volume).

Distant cell signals that utilize the circulatory system to emit a slow and long-lasting response.

Cell signalling in which a cell secretes hormones that diffuse into either lymph vessels or the bloodstream to reach distant cells in the body.

System of glands that produce hormones to regulate and control bodily activities.

The process by which particles are moved within a cell.

The inner lining of the uterus that grows to become thick, and vascular in preparation for pregnancy.

Bacteria that resides in the intestines.

Cells that line small and large intestine surfaces, otherwise known as the intestinal absorptive cells.

Hormone-producing cells located in the GIT, pancreas, and stomach.

A type of glial cell that lines the ventricles of the CNS and act to produce and regular cerebrospinal fluid.

A tube behind the testis that carries sperm to the vas deferens.

The process of turning an action potential into a muscle contraction.

Depolarization that causes the membrane potential to move closer to firing threshold.

In terms of the kidney, whatever fluid remains in the tube is released from the body to the external environment.

Being caused by external factors.

In addition to tidal volume, the maximum amount of air that be expired.

Body fluid that is not contained in cells (e.g. blood, lymph).

Regulation by factors originating outside the tissue.

A minor pancreatic islet cell type that produces the hormone pancreatic polypeptide. Also known as PP cells.

A transportation mechanism that moves a substance down its concentration gradient. Requires specific membrane receptors or channel proteins for movement.

Modification or control of a process using its anticipated results or effects.

The formation of a circuit in which outputs of a system route back as inputs promoting cause-and-effect. The system can either be amplified (positive) or inhibited (negative feedback).

How long the heart is in diastole. If the filling time is too quick there will be no blood to pump out, if it is too long blood will start to pool in the filling chamber.

In the kidney, filtration indicates the movement of water and substrates from the plasma into the renal tubule.

Stimulates the growth and recruitment of immature ovarian follicles in females. In males, it is critical for spermatogenesis as it stimulates primary spermatocytes to form secondary spermatocytes.

A small pit in the retina of the eye that is necessary for sharp central vision in actions such as reading. Light rays in this area fall directly on cone cells.

The anterior lobe of the cerebral cortex that is involved in voluntary movement, language, and executive function (higher level thinking).

The breakdown of a system into smaller more detailed sections or "compartments" that all work together to produce one main outcome or "function".

The amount of air remaining in the lungs after normal expiration.

Membrane protein required for neurotransmitter signalling by metabotropic receptors. Involved in regulation of ion channels and effector enzyme synthesis or breakdown.

A type of membrane receptor with 7 transmembrane domains that can be activated by multiple ligands, leading to the conversion of GDP into GTP and activation of a signalling cascade.

The reproductive cells of an organism.

The retinal neurons that are responsible for carrying visual information from the photoreceptors into the brain. The axons of many ganglion cells constitute the optic nerve.

Intracellular connection that connect the cytoplasm of two cells that allow molecules and ions to pass through.

The delivery of oxygen from the inhaled air in the lungs into the blood and the removal of carbon dioxide from the blood into the exhaled air in the lungs.

The volume of filtrate formed by both kidneys per minute.

Dense network of capillaries and the site where kidney filtration begins.

A catabolic hormone which promotes the increase of glucose in the bloodstream by converting glycogen stores in liver to glucose via glycogenolysis.

The process of making glucose from non-carbohydrate carbon substrates, including lactate, glycerol and amino acid.

Tissues will not use glucose and will use other fuel (lipids) instead. Because glucose is not being used, it accumulates in the blood and can cause hypoglycemia.

Excitatory amino acid neurotransmitter.

A large, branched polysaccharide that serves as the primary storage form of glucose.

Synthesis of glycogen from glucose.

The process by which glycogen is broken-down into glucose.

The process of converting glucose into energy.

Any class of proteins that have carbohydrate groups attached to the polypeptide chain.

Thyroid gland enlargement that causes neck swelling.

An equation used to calculate membrane potential which takes multiple ion species into account.

A sensory organ that receives information from the tendons; senses changes in tension exerted by muscles.

Stretch receptors in the tendons of muscles which sense the force of a contraction.

A hypothalamic hormone that acts on the pituitary gland to produce FSH and LH, which is released in systemic circulation to act on target tissues.

The modulation of membrane potential of an excitable cell by the integration of several excitatory or inhibitory signals.

The time it takes for hormones to lose half of its activity by degradation or elimination.

The number of cardiac cycles that are completed per unit time (in beats/minute).

A protein responsible for transporting oxygen in the blood. It's molecule is comprised of four subunits, each containing an iron atom bound to a heme group.

A drug used to prevent the formation of blood clots.

Cells in the liver that play a role in metabolism, protein synthesis, and detoxification.

A reflex that is triggered to prevent the over-expansion or inflation of the lungs.

Mechanoreceptors that respond to changes in the tension of arterial walls.

A state of relatively stable equilibrium in the body that is maintained by constant adjustment of biochemical and physiological pathways.

Signalling chemicals secreted by endocrine cells. These chemicals may be released onto the extracellular space or the bloodstream.

The tendency to repel or fail to mix with water.

The pressure that blood exerts on the walls of vasculature at the level of capillary. This force drives the movement of fluid from the blood into the interstitium.

A solution with a higher concentration of solutes than another solution.

A condition characterized by blood calcium levels that are higher than normal.

Excessive amounts of CO2 (carbon dioxide) in the bloodstream.

Elevated blood glucose.

Dangerously high potassium levels in the body.

A condition in which the parathyroid gland is producing and releasing too much parathyroid hormone, resulting in an increase in blood calcium levels.

A condition characterized by blood phosphate levels that are higher than normal.

The change in a cell's membrane potential that makes it more negative than the resting membrane potential.

High levels of prolactin in the blood.

The solute concentration of one solution is greater than another.

Rapid and deep breathing.

A solution with a lesser concentration than another.

A condition characterized by blood calcium levels that are lower than normal.

Low blood glucose.

A condition in which the parathyroid gland is producing and releasing too little parathyroid hormone, resulting in low levels of blood calcium.

A condition characterized by blood phosphate levels that are lower than normal.

The connection of blood vessels between the hypothalamus and pituitary gland.

The connection of blood vessels between the hypothalamus and the pituitary gland. This is also called the hypophyseal portal system.

Small portion of the brain that regulates metabolic processes, serving as a link between endocrine and nervous systems via the pituitary gland.

Breathing at an abnormally slow rate.

Abnormally low concentration of oxygen in the blood.

Not enough oxygen to properly function.

Midbrain nucleus mainly involved in auditory pathways. All auditory pathways travelling through the midbrain converge at the inferior colliculus.

Also known as the pituitary stalk, the infundibulum connects the hypothalamus to the pituitary gland.

A hormone secreted by the Sertoli cells in the testes and by the granulosa cells in the ovary, which inhibits the release of FSH from the pituitary.

Hyperpolarization of the post-synaptic cell that causes the membrane to move further from firing threshold.

The medial segment of the photoreceptor that contains the nucleus, mitochondria and ribosomes. Responsible for metabolism of the cell.

Location where the synapsing of axons from bipolar cells occurs with dendrites of retinal ganglion cells.

The maximum amount of air inspired after normal expiration.

In addition to tidal volume, the maximum amount of air that can be inspired.

An anabolic hormone that allows glucose uptake into cells.

Very similar to insulin and exhibit indirect GH effects on metabolism.

The combination of signals, both excitatory and inhibitory, from various origins that will influence the action or inaction of the body.

Found in the collecting duct and play a significant role in regulating blood pH. Intercalated cells reabsorb K+ and HCO3- while secreting H+.

Extracellular fluid found throughout the whole body.

The interstitial space is a fluid-filled space that allows the free movement of ions, also referred to as interstitial fluid.

Fluid contained within cells.

Regulation by a factor originating from within the tissue.

Muscle contractions that are autonomous, done without thinking.

Respiration that occurs without conscious control.

Protein expressed by virtually all living cells that creates a pathway for charged ions from dissolved salts (including sodium, potassium, calcium, and chloride ions) to pass through the otherwise impermeant lipid cell membrane.

Fast acting receptor that has an ion channel at its centre that is controlled by the binding of neurotransmitters to specific sites on the receptor. AKA ligand-gated ion channel.

The coloured part of the eye that is responsible for contracting or relaxing depending on the intensity of light in the environment. The iris is an involuntary sprinter muscle.

Sensors that respond to both mechanical and chemical stimuli and protect the lung from harmful chemicals and foreign particles.

No change in volume despite a large increase/decrease in pressure. We see this phenomenon when pressure builds in the ventricles in preparation for systolic contraction.

A type of muscle contraction where the muscle is not lengthening or shortening, but rather is at a constant length.

Having the same concentration as another solution.

A structure formed by the distal convoluted tubule and the glomerular afferent arterioles. Involved in the regulation of blood pressure and GFR.

One out of two types of nephrons. In contrast to cortical nephrons, juxtamedually nephrons have a loop of Henle and they extend deep into the renal medulla, unlike cortical nephrons.

An enzyme that promotes the breakdown of lactose to galactose and glucose.

An excited neuron in one signal pathway inhibiting a neighbouring neuron of a different signal pathway.

A fold on the lateral side of the brain. Used as a landmark, or border, for where the frontal and parietal lobes end, posteriorly and laterally respectfully, and where the temporal lobe begins anterior-medially.

An ion channel in a cell membrane that is always open, making the membrane permeable to ions. Also referred to as non-gated channels.

Leaky tight junctions are found between the cells of the ascending limb of the loop of Henle, where they allow the movement of certain solutes.

A small, transparent structure deep to the pupil that will refract light onto the retina. The amount of refraction by the lens is modified by the ciliary muscles depending on the distance of the object.

Adjacent to the seminiferous tubules, these interstitial cells produce testosterone in the presence of LH. Numerous factors secreted by other cells act on leydig cells to regulate testosterone production.

Protein channels that allow substances to pass through in response to binding of a chemical messenger (ex. a neurotransmitter).

Made up of the hypothalamus, the hippocampus, and the amygdala, and is primarily responsible for emotion.

Hormones that can easily cross the plasma membrane and interact with cytosolic or nuclear receptors.

Synthesis of fatty-acids from non-lipid precursors.

Breakdown of fats by hydrolysis to release fatty acids.

Mechanisms through which organs and tissues alter themselves independent of nerves or hormones.

Phenomenon where synaptic connections are strengthened. Requires the activation of NMDA and AMPA receptors.

A part of the nephron where water and solute reabsorption takes place.

A hormone produced by gonadotropic cells of the anterior pituitary gland. It triggers ovulation and development of the corpus luteum in females and stimulates production of testosterone of leydig cells in males.

Densely packed specialized cells on the wall of the distal convoluted tubule (DCT), found at the point where the thick ascending limb meets the DCT.

Large cells pathway that will signal to the brain about the form of an object, the depth of the object and/or the difference in intensity from multiple objects.

The minor calyces merge to form a few major calyces. The major calyces then drain into the renal pelvis.

An enzyme that facilitates the breakdown of maltose to two glucose molecules.

The average arterial pressure during one cardiac cycle.

Breaking food into pieces that are smaller and more nutrient accessible.

The process in which a single cell divides twice to produce four daughter cells. Each cell has one copy of each chromosome. In males, this process usually produces four viable gametes. In females, only one gamete is typically produced.

The difference in electrical potential between the inside and outside of a cell.

A process that thickens the lining of the uterus and prepares it for implantation of an egg (pregnancy). If there is no pregnancy (egg), there will be menses, the sloughing of the uterine lining.

Slow acting receptor that activates G-proteins when activated. AKA G-protein coupled receptor.

Aggregates of lipids such as fatty acids and monoglycerides.

A type of glial cell that acts as the immune defense of the CNS, as macrophages.

Projections from the epithelial cells lining the villi to increase surface area.

Part of the urinary system, the minor calyces sit under the apex of the renal pyramids. Urine formed in the kidneys dumps into the minor calyces.

A single part. “Mono” means one and “mer” means part.

The motor neuron and its associated skeletal muscle fibres, which work together to coordinate movement of skeletal muscles.

Secreted from mucous glands, an aqueous substance that coats mucous membranes.

A muscle cell.

Stretch receptors in the muscle that detect changes in its length.

Small sensory units inside the muscle which lie parallel to the extrafusal fibers. These units relay sensory information about the stretch of a muscle to the CNS.

A layer of fatty tissue that surrounds the axons of neurons leading to faster neural communication.

The formation and development of a myelin sheath around the axon of a neuron, which is affected by neuroglia, such as Schwann cells.

Nervous tissue located between the circular and longitudinal muscles.

A mechanism of auto-regulation where vascular smooth muscle can contract in response to increasing pressure.

A graphical representation of muscle activity.

One of the two protein filaments that make up a sarcomere; thick filament.

Occurs when some function of the output of a system, process, or mechanism, is fed back in a manner that tends to reduce the output.

The functional unit of the kidney that is located in the renal cortex and the renal medulla.

An equation that is used to calculate the electrical potential across a membrane when the membrane is permeable to a single ion.

Any collection of neuron axons that are found in the PNS.

The network of nerve cells and fibers which transmit nerve impulses between parts of the body.

The means of communication between nerve cells where electrical signals are transmitted along a nerve due to internal or external stimuli.

The mechanism by which sensory information is converted into motor output by taking information from sensory receptors through action potentials and relaying it to appropriate centers in the brain, who then send our signals to create the appropriate response.

The innermost portion of the eye, also known simply as the retina. It lines the innermost part of the eye and contains photoreceptors.

Cell signalling in which nerves secrete chemical neurotransmitters into the extracellular space that diffuse into the bloodstream and interact with different tissues in the body.

A chemical synapse formed between a motor neuron and a muscle fiber.

A nerve cell that receives and sends electrical signals over long distances within the body.

Chemical released at synapses by nerves in response to a stimulus.

Type of cardiac cell that is involved in the electrical system of the heart. Examples: Atrioventricular node and Sinoatrial node.

Periodic gap in the insulating sheath (myelin) on the axon of certain neurons that serves to facilitate the rapid conduction of nerve impulses.

Ion channels that are always open. Another common name for these channels is “leak” channels because they simply allow ions to pass through the channel without any impedance.

Hormones that cannot cross the plasma membrane of cells.

A type of intrafusal muscle fibre that make up the muscle spindle; are dynamic in nature.

A type of intrafusal muscle fibre that makes up the muscle spindle; are static in nature.

The most posterior lobe which functions to process visual information in order to perceive what we see.

A type of glial cell that myelinate neurons in the CNS.

The osmotic force generated by the presence of proteins in the blood that draws fluid from the interstitium into the vasculature.

[of vision] A theory that proposes that colour vision is controlled by three antagonistic colour pairings (black/white, red/green, blue/yellow) and when only one colour in the pair can be firing at a given time.

Light-sensitive proteins found in photoreceptors of the retina.

The crossing of the optic tract from the left eye that is heading to the right lateral geniculate nucleus with the optic tract from the right eye that is heading to the left lateral geniculate nucleus.

Another name for the blind spot, where the retinal ganglion cells exit the eye as the optic nerve.

A cranial nerve of the brain that transfers visual information from the retina to the occipital lobe.

Areas of the brain that enable the perception of vision.

Binding site on a receptor where the endogenous ligand binds. AKA the active site.

The concentration of a solution.

The movement of water (or another solvent) from an area of higher water concentration to an area of lower water concentration (through a semipermeable membrane).

Cells responsible for forming new bone.

Cells responsible for reabsorbing (breaking down) bone.

[of a photoreceptor] Modified cilia that are made up of discs filled with opsins that absorb light.

Also known as the outer plexiform layer, this is a layer of cells where synapsing of dendrites of horizontal cells, bipolar cells, and photoreceptor cells occurs in the retina.

In this cycle, an ovarian follicle matures and ruptures, releasing an egg, eventually forming a corpus luteum.

Control heart rate and blood flow by influencing rhythmic electrical impulses.

The speed that a pacemaker cell causes the heart to beat (beats/min).

A glandular organ with both exocrine and endocrine functions that is important for digestion and regulation of blood glucose.

An enzyme produced by the pancreas that is released into the small intestine to breakdown carbohydrates.

A form of cellular signalling in which cells that are near one another communicate through the release of chemical messengers, allowing cells to locally coordinate their activities.

Commonly known for “rest and digest” of the body, this system promotes digestion and relaxation, and decreases heart rate.

 A hormone secreted by the parathyroid glands that plays a role in regulating blood calcium concentration.

Lobe located medial and superior in the cerebral cortex. The functions are to integrate sensory information from several locations, help plan how to interact with objects and to distinguish where objects are in space.

A deep groove at the posterior side of the brain that separates the posterior edge of the parietal lobe and the anterior edge of the occipital lobe.

Small cells in the lateral geniculate nucleus that detect information regarding the colour and fine details of objects.

The amount of blood flow to the alveoli.

Located in the carotid artery and aortic arch.

The contraction of a muscle pushing contents of a tube in a linear fashion.

The efferent arterioles that exit the glomerulus and become tiny blood vessels.

Cells that contract and propel sperm to the next location where it will continue to mature.

A hormone that requires the presence of an additional hormone to have its full effect in the body; the additional hormone by itself will have no effect.

The non-specific uptake of large particles into a cell.

A thin polar membrane made of two layers of lipid molecules.

A type of cell found in the retina that detects photons of light and converts them into electrical signals for the brain.

Similar to mechanical digestion, it involves breaking food into pieces that are smaller and more nutrient accessible.

The non-specific uptake of solutes and water from the extracellular fluid.

An endocrine gland consisting of anterior and posterior portions that secrete hormones in response to hypothalamic stimuli.

Thin fluid-filled space between the visceral and parietal pleurae of each lung.

The air pressure within the pleural cavity that varies during ventilation.

Lung inflammation caused by bacterial or viral infection, in which the air sacs fill with pus and may become solid.

Occurs when some function of the output of a system, process, or mechanism is fed back in a manner that tends to increase the output.

Metabolic state achieved after complete digestion and absorption of a meal.

Pituitary gland lobe that does not produce its own hormones. Hormones synthesized in the hypothalamus reach the posterior pituitary where they are secreted in systemic circulation.

Neuron at the synapse that receives the signal from the post-synaptic cell.

Neuron at the synapse that transmits the signal to the post-synaptic neuron.

Movement of substances across a cell membrane using ATP for energy.

A region of the occipital lobe where information from both optic nerves converges; this region acts to sort and integrate visual information.

Found in the collecting duct, these cells possess channels for the recovery or loss of sodium and potassium.

Multiple projections from a body (soma) that includes dendrites and an axon.

The precursor to a hormone. A prohormone does not have a direct biological effect but may act as a reservoir for one that does and can be converted to a biologically active hormone.

The action potential travels down the axon as voltage-gated ion channels are opened by the spreading depolarization.

The ability of the body to perceive its position in space and the position of each body part relative to others.

Pushing something in one direction.

A group of biologically active lipid compounds important in many body functions including contraction and relaxation of muscle, dilation and constriction of blood vessels, blood pressure control, and control of inflammation.

A protein that allows transport of specific substances across a cell membrane.

Enzymes that catalyze the phosphorylation of other proteins.

The function of the tubular network of the nephron is to discern nutrients from wastes and selectively replenish the blood with the water, salts, and nutrients that entered the filtrate.

Period of time at which a person is first capable of sexual reproduction.

The blood flow that is directed towards and through the lungs.

Abnormal buildup of fluid in the lungs.

Charge within the cell returns to being more negative (downward slope of the curve).

In terms of kidney physiology, reabsorption is when the kidney removes water and solutes from the nephron and returns them to circulation.

The uptake of specific molecules via binding to receptors on the plasma membrane and formation of vesicles intracellularly.

A variable that is being sensed and maintained by a homeostatic system.

The period during which a stimulus must be supermaximal to generate another action potential.

A fibrous layer that surrounds the surface of the kidney. The capsule is important as it cushions and protects the kidney via it's layer of adipose tissue.

A region of the kidney that is an extension of the renal cortex. Renal columns are situated in between the renal pyramids.

The component of the nephron that is responsible for the filtration of blood.

The outer region of the kidney. Erythropoietin is produced here.

The inner portion of the kidney, consisting of the renal pyramids and the renal columns. This inner region is where kidney filtration occurs; clearing the plasma of unwanted substances and regulating blood volume.

Triangular shaped cones within the renal medulla of the kidney.

An enzyme produced by the granular cells of the afferent arteriole at the JGA. It enzymatically converts angiotensinogen to angiotensin I.

The amount of air remaining in the lungs after normal tidal expiration.

Detects blood CO2 levels by monitoring the concentration of hydrogen ions in the blood.

The reactionary action undergone by the body following the perception of stimuli.

The relatively static membrane potential of quiescent cells.

Thin layer of tissue that lines the insides and back of the eye that acts to convert light that falls onto it into neural signals for visual transduction.

The most proximal neuron in the retina of the visual pathway. Axons of these neurons make up the optic nerve.

A G-Protein coupled receptor that is the most abundant protein in rod cells of the retina; plays a key role in low-light vision.

[cell type] Photoreceptor cells in the retina found on the outer edge of the eye that are highly sensitive to light and contribute to peripheral vision.

An enzyme in saliva that separates carbohydrates into smaller molecules.

The propagation of action potentials along myelinated axons from one Node of Ranvier to the next, increasing the speed of conduction.

The cell membrane of a striated muscle cell.

The contractile unit of a muscle fiber, composed of sliding protein filaments of actin and myosin.

The cytoplasm of a striated muscle cell.

A structure, similar to the endoplasmic reticulum, that is found in striated muscle fibers. Its main function is to store calcium ions.

A type of glial cell found in the PNS that provide protection and nutrient support to neurons.

A type of glial cell that myelinate neurons in the PNS.

Substance that when activated initiates intracellular biochemical process.

A form of active transport across a cell membrane where a carrier protein couples the movement of a substance with its concentration gradient to the movement of another substance against its concentration gradient.

The process of removing a substance out of the bloodstream and into the urine.

The site of male gamete production (spermatogenesis).

Sensory information from any form of stimuli that is received from the body.

Cells that secrete a number of growth factors and activating proteins to ensure an optimal environment for spermatogenesis. This process is stimulated by FSH.

A thick layer of epithelial cells that secretes and absorbs substances.

A mechanism of transport that moves substances from an area of high to low concentration. No energy is needed.

A thin layer of cells that is permeable and allows small molecules to cross via diffusion and filtration. The simple squamous epithelium also secretes lubricating substances.

A cluster of spontaneously depolarizing nodal cells that are located in the right atrium. They conduct action potentials at the fastest speed and therefore set resting heart rate.

Low pressure blood vessels that deliver portal and arterial blood to central veins.

One of the three types of muscle tissue found in the human body. Skeletal muscle is under voluntary control and is attached to your joints to produce movement during contraction.

The small fluctuation of membrane potential due to the movement of ions.

One of the three types of muscle tissue found in the human body. Smooth muscle is under involuntary control and is found in a variety of internal organs, including the intestines, bladder, and blood vessels.

An important membrane transporter that uses primary active transport to move sodium ions and potassium ions against their concentration gradients (from areas of low concentration to high concentration).

The process in which a substance becomes soluble or more soluble than it was.

The aspect of the nervous system that is voluntarily controlled, therefore actions are carried out by stimulating skeletal muscle to contract.

The summation of inputs that modulate a graded potential that come from different pre synaptic neurons.

Male gametes.

The process of sperm production within the seminiferous tubules in the testes.

Sperm cell produced in the early stages of spermatogenesis; immature sperm.

Circular muscle that opens or closes the end of a tube.

An action potential generated from the combination of a slow wave and a stimuli.

Nerves that innervate the sympathetic nerves of the autonomic nervous system.

A detectable change in the physical or chemical structure of an organism's internal or external environment.

The deformation or change in shape and size of material.

Mechanoreceptors that respond to mechanical stretch or distortion.

A signal telling the stretched muscle to contract in order to prevent over stretching.

Muscle that is controlled in a voluntary manner.

Volume of blood ejected from the heart each cardiac cycle (mL).

Nervous tissue located between the submucosa and circular muscle.

An enzyme that promotes the breakdown of sucrose to glucose and fructose.

For chemical (NT) signals there is not a one-to-one signal-to-action potential, several excitatory and inhibitory signals add together. In order to get an action potential there must be enough excitatory signals to outweigh the inhibitory signals to cause depolarization.

A midbrain structure in the visual pathway that will adjust eye movements in response to the light stimuli it is receiving.

A region in the hypothalamus of the brain that resides just above the optic chiasm; regulates the body’s circadian rhythm.

A compound which reduces surface tension when added to a liquid.

Prepares the body to respond to stress, such as a threat or injury. It is often referred to as the “fight-or-flight” response.

A carrier protein that transports two different molecules in the same direction across the cell membrane.

Space between two cells, consisting of the pre-synaptic neuron, synaptic cleft, and the post-synaptic neuron. Involved in the transmission of information between two cells.

Small gap between the pre-synaptic and post-synaptic neuron, about 20nm wide.

The circuit that provides oxygenated blood to the entire body, except the lungs (blood moving to and from the lungs is considered pulmonary circulation).

The pumping or contraction phase of the heart.

Extensions of the cell membrane that go into the centre of striated muscle fibers at the Z-lines.

Bilateral lobes found behind the ears. They are responsible for processing auditory information and for forming and storing memories.

The summation of inputs that subsequently occur following the current spatial summating signals.

The male gonads in animals.

Steroid hormone produced primarily in the male testes and responsible for the development of male secondary sex characteristics.

Electrical stimuli delivered repeatedly that causes long term potentiation.

The membrane voltage that must be reached in an excitable cell (e.g., neuron or muscle cell) during a depolarization in order to generate an action potential.

Prohormone is converted to the biologically active form of thyroid hormone (T3) at target tissues.

The amount of air inspired in each breath during quiet breathing.

A representation of the locations of organs/receptors and their direct relation to other parts of the body.

The total amount of air in the lungs after maximum inspiration.

The sum of the vascular resistance in each vessel in the circulatory system.

Any collection of neuron axons that are found in the CNS.

Transport of solutes by a cell through a cell.

The difference between the pleural pressure and the alveolar pressure.

Biologically active form of thyroid hormone.

A protein complex that covers the binding sites for myosin on actin.

The body is unable to utilize synthesized insulin properly or it can’t make enough insulin. As a result, blood sugar levels increase.

A carrier protein that transports one specific molecule across the cell membrane.

An increase in the production of a target receptor that causes an increase in the body's sensitivity to a particular hormone.

A measure of an element that determines the combining capacity the element has with other atoms when it forms chemical compounds and molecules.

The duct in the testes that carries semen from the epididymis to the ejaculatory duct.

Blood vessels that surround the loop of Henle.

The arrangement of blood vessels within an organ or body part.

Contraction of smooth muscle cells and the tightening of blood vessels. This will allow for less blood flow through the vasculature.

Relaxation of smooth muscle cells and the widening of blood vessels. This will allow for more blood flow through the vasculature.

Vessels that bring oxygen depleted blood back to the heart.

Blood flow back to the heart within a cardiac cycle. If venous return does not equal CO it could be evidence of blood pooling or a blockage somewhere.

The process of moving air into and out of the lungs to facilitate gas exchange.

A pathway on the ventral side of the brain that carries visual information from the primary visual cortex to the temporal lobe; this pathway is responsible for object recognition and discrimination of forms of shapes.

Large lower compartment of the heart which pumps blood out to the body.

Small blood vessel that allows blood to flow from capillary beds to veins.

A lipoprotein made by the liver that carries triglycerides to tissues.

Projections that stem from the inner lining of the small intestine to increase surface area.

The sharpness of vision. The ability to discern patterns and shapes from a distance (measured using an eye chart).

The maximum amount of air that can be exhaled after a maximum inspiration.

A nutrient in food that is converted into an active hormone that aids in controlling plasma calcium concentration.

Clear liquid found between the lens and the retina of the eyeball which helps maintain the shape of the eye and provide shock absorption.

Protein channels that are activated by changes in the electrical membrane potential near the channel.

Transmembrane channels that are specific to potassium and sensitive to voltage changes in the cell's membrane potential. During action potentials, they play a crucial role in returning the depolarized cell to a resting state.

Transmembrane proteins that are responsible for the rapid depolarization that underlies the upstroke of action potentials in neurons, and are crucial to the nerve impulse conduction.

Muscle contractions done by conscious choice.

Respiration that occurs under conscious control.