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72 Cards in this Set
- Front
- Back
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Benefits of regulation |
Cells function in steady conditions(oscillation), independent of variations in outside conditions |
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benefits of conformity |
conformity is energetically cheap |
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Negative feedback |
the system opposes deviations from a set point |
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positive feedback |
reinforces deviations from a set point |
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Hormone |
an endocrine cell secreated a chemical signal into the blood stream |
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neurotransmitter |
chemical substance released from the presynapic cleft into the synaptic cleft |
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Internal environment |
fluid that surrounds the cells. The stomach juices etc in the digestive system are considered part of the external environment though fyi |
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Higher magnitude oscillations observed in regulation |
the particular system is more important because it requires more energy to keep a regulatory system precise at all times. |
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action potentials |
nerve impulses |
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Resting membrane potential |
When the inner memebrane is surface is negative with respect to the outer membrane surface. |
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Depolarization |
n the process of depolarization, the negative internal charge of the cell becomes positive for a very brief time. While the sodium potassium pump continues to work, the voltage gated ion channels that had been closed while the cell was at resting potential have been opened by an electrical stimulus. As the sodium rushes back into the cell the positive sodium ions raise the charge inside of the cell from negative to positive. Once the interior of the cell becomes positively charged, depolarization of the cell is complete. |
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Re polarization |
repolarization refers to the change in membrane potential that returns it to a negative value just after the depolarization phase of an action potential has changed the membrane potential to a positive value. The repolarization phase usually returns the membrane potential back to the resting membrane potential. The efflux of K+ ions results in the falling phase of an action potential. The ions pass through the selectivity filter of the K+ channel pore. |
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threshold potential |
The critical level to which a membrane potential must be depolarized to initiate an action potential. |
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Example of positive feed back |
depolarization of the membrane. Activation gate of Na+ channels open |
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Nerst Equation |
R = gas constant, which is 8.31 T = temperature (K) Z = valance of ion F = Faraday's constant, 96500 coulombs/mol |
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Donnan equilibrium |
occurs across a membrane when a number of ions (anions and cations) can cross the membrane but there is set of non permeating ions that are more abundant on one side than the other |
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excitable cells |
can undergo action potentials (muscles and nerves) |
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Non excitable cell |
have membrane potentials buts cannot sent signals(open gates-Voltage sensitive channels) |
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why does the myelin sheath work? |
the myelin sheath covers the axon leaving only little breaks (nodes) along the neuron. Less action potentials=less time opening channels=faster |
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Node |
ares on a nerve cell with the sodium gate depolarization/polarization chemical mechanism. It is converted to and electrical mechanism which causes jumping from node to node |
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How does a larger diameter effect the speed of action potential? |
it speeds it up |
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excitatory postsynaptic potentials |
postsynaptic potential that makes the neuron more likely to fire an action potential. This temporary depolarization of postsynaptic membrane potential, caused by the flow of positively charged ions into the postsynaptic cell, is a result of opening ligand-gated ion channels. They are graded...which means they have an additive effect). When multiple EPSPs occur on a single patch of postsynaptic membrane, their combined effect is the sum of the individual EPSPs. Larger EPSPs result in greater membrane depolarization and thus increase the likelihood that the postsynaptic cell reaches the threshold for firing an action potential. |
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inhibitory postsynaptic potential |
kind of synaptic potential that makes a postsynaptic neuron less likely to generate an action potential |
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temporal sumation |
only one nerve is stimulated repeatedly and rapidly. The EPSPs combine to create the action potential
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spacial summation |
simultaneously occurring EPSP produced by different nerves
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Acetylcholine |
neurotransmitter—a chemical released by nerve cells to send signals to other cells. Binds loosely to receptors( comes on and off) 1.action potential depolarization of axon terminal of motor neuron 2.calcium channels open 3. depolarization of the terminal triggers vesicle exocyotsis, releasing acetylcholine 4. ACh binds to recepotrs 5.the receptor channel opens allowing Na+ K+ to flow into the cell. 6. contraction of the muscle occurs 7. acetylcholinesterase hydrolyzes the acetylcholine into acetate choline. 8. Choline is actively transported back into te motor axon terminal to be resynthesized into acetylcholine |
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Acetylcholinesterase |
Breaks up acetylcholine and stops any unwanted binding in the cleft. The chlorine group is actually recycled( but that is not related to the process) |
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adrenergic receptors |
a class of G protein-coupled receptors. norephedrine, dopamine, epinephrine(adrenaline). Excess taken back into the cells is required |
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afferent neuron |
Nerve cells that carry information toward the central nervous system (or farther centrally within the spinal cord and brain) |
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efferent neuron |
nerve cells that carry information away from the brain or spinal cord (or away from the circuit in question) |
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convergent neural circuit |
Multiple inputs converge to a single neuron (many → one) From a single source - multiple synaptic terminals from the pre-synaptic neuron communicate with a single post-synaptic neuron → anatomical basis of spatial summation of multiple EPSPs, to finally excite the post-synaptic neuron. From multiple sources (excitatory or inhibitory) - this allows different tracts to excite a single neuron thus allowing summation of information from different sensory organs → high-level analysis of the afferent signals. |
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simple feedback neural circuit |
Red=inhibitory green= excitatory |
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Endocrine glands |
"ductless glands"-no tubes coming out and directing the secretion Hormones are secreted directly into the blood stream to the target cells/organs |
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Target cells/organs |
groups of cells that have receptors for the hormone, cells can see the hormone |
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Epinephrine, Norepinephrine |
Catecholamines comes from the adrenal gland. Response to stress and exercise. Increases blood glucose levels by promoting the break down of glucose. Promotes cellular glucose up-take. Promotes degradation of triglycerides to form free fatty acids and glycerol. promotes degradation of proteins to form free fatty acids. Increase heart rate/breathing. Digestive functions are surpressed. There is hightened alertness |
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Acetylcholine |
it is the chemical that motor neurons of the nervous system release in order to activate muscles. Acetylcholine exerts its effects by binding to and activating receptors located on the surface of cells |
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TRH |
Thyrotropin-releasing hormone (TRH):produced by the hypothalamus, that stimulates the release of thyrotropin (thyroid-stimulating hormone or TSH) and prolactin from the anterior pituitary |
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TSH |
Thyroid-stimulating hormone: a pituitary hormone that stimulates the thyroid gland to produce thyroxine which stimulates the metabolism of almost every tissue in the body.[1] It is a glycoprotein hormone synthesized and secreted by thyrotrope cells in the anterior pituitary gland, which regulates the endocrine function of the thyroid. |
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Thyroxine |
secreted continuously by the thyroid gland. Rate of secretion increased by TRH and TSH. Promotes oxidation of nutrients (raises metabolic rate). Stimulates growth hormone secretion and enhances the effects of growth hormone on synthesis of new protiens |
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CRH |
Corticotropin-releasing hormone. neurotransmitter involved in the stress response. It is a releasing hormone that belongs to corticotropin-releasing factor family. Its main function is the stimulation of the pituitary synthesis of ACTH. Secretes into the median eminence where it is transported into the anterior pituitary |
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ACTH |
Adrenocorticotropic hormone (ACTH) Is often produced in response to biological stress BY THE PITUITARY (along with its precursor corticotropin-releasing hormone from the hypothalamus). Its principal effects are increased production and release of GLUCORITICOIDS by the cortex of the adrenal gland. |
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Glucocorticoids |
Used to maintain HOMEOSTASIS released by the adrenal gland. Stimulated by stress. Enhances the actions of glucagon. increases blood glucose levels. promotes degradation of triglycerides to form free fatty acids. promote degradation of proteins to form free amino acids (cortisone,corisol, and corticosterone) |
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insulin |
secreted by the pancreas. Stimulated by high blood glucose, high blood amino acids, gastrointestinal hormones, parasympathetic stimulation. Increases glucose uptake from the blood by resting skeletal muscle cells and fat cells. promotes formation of glycogen from glucose in the muscles and the liver. stimulated fat cells to synthesize triglycerides from glucose. promotes use of glucose in atp production, promotes protein synthesis |
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glucagon |
opposite function of insulin: it stimulates the release of glucose and fatty acids in the blood |
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renin |
THIS SYSTEM IS INDEPENDENT OF CNS! Release is stimulated by the kidneys J-G cells which are blood pressure, and sodium dependent. Triggered by a drop in both this is a sodium retaining process renin is the enzyme that cleaves active angiotensinogen
Renin+angiotensinogen= angiotensin I |
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Angiotensin |
Angiotensin is a peptide hormone that causes vasoconstriction and a subsequent increase in blood pressure. Stimulated by renin It is part of the renin-angiotensin system, which is a major target for drugs that lower blood pressure. Angiotensin also stimulates the release of aldosterone, another hormone, from the adrenal cortex. Comes from the cleavage of angiotensiogen into angiotensin I. Angiotension 1: needs to encounter an angiotension-converting enzyme to become angiotensin 2, Anguitension 2 stimulates the secretion of aldosterone from the adrenal cortex |
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Aldosterone |
Aldosterone tends to promote Na+ and water retention, and lower plasma K+ concentration. raises blood pressure |
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Calcitonin |
chief cells in the parathyroid(NOT CNS) secrete cacitonin when calcium levels are high calcitonin lowers blood Ca2+ levels in four ways: Inhibits Ca2+ absorption by the intestines Inhibits osteoclast activity in bones Stimulates osteoblastic activity in bones. Inhibits renal tubular cell reabsorption of Ca2+ allowing it to be excreted in the urine |
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Parathyriod hormone |
secreated by 'cheif cells' in the parathyroid(NOT CNS) gland when calcium levels are low Under the presence of parathyroid hormone, bones will give up their calcium in an attempt to increase the blood level of calcium. Under the presence of parathyroid hormone the lining of the intestine becomes more efficient at absorbing calcium normally found in our diet. reabsorbs calcium through the kidney |
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Vasopressin/Antidiuretic Hormone (ADH) |
A neurohormone (neurorelfex) RELEASES FROM THE PARS NERVOSA NOT ANTIERIOR PITUTIARY Specific input (e.g. low blood presure, high salt,) -> neural message to brain -> integration->neural stimulation of neurosecretory cells -> release of hormone limits the production of urine and also stimulates the constriction of arteries. Triggered by input from blood volume and osmotic concentration . When osmotic concentration is high or blood volume is low, it causes the body to retain water. sythesized by by neurosecretory cells that have their cell bodies in the hypothalamus and their axon terminals in the posterior pituitary |
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energy metabolism |
the sum total of the processes by which animals acquire, interconvert, use, and dispose of energy |
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3 uses of energy |
1.synthesis of organic materials-growth 2. maintains functions-rebuilding 3. external work-walking, excersize, transporting ions to the kidney |
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Factors that affect B.M.R |
1.resting-excersice increases BMR 2. fasting 3. temperature (does not apply to fish and reptiles) |
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Standard M.R. |
used when you cannot use tempreture to find the metabolic rate of an animal (used for fish and reptiles) |
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Homeotherm |
can maintain body temperature by physiological means not just by behavior |
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poikilothermy (ectotherm) |
body temp is irregular. Body temp is high at high temperatures and low at low temperatures. |
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Endotherm |
can internally generate heat via their metabolism |
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behavioral thermoregulators |
a poikilotherm that behaviorlally maintains a relatively constant body tempreture. ie fish that are only found at the bottom of the ocean |
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thermoneutral zone |
an animals resting metabolic rate is independent of ambient temperature and is constant. has a lower critcal temperature and an upper critical temperatue |
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rumen |
first and largest compartment in forgut fermenting animal. Communites of microbes are abundant in this non acidic environment. When the ruminant eats the chamber ferments the meal. |
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process of food handling |
ingestion--> getting food in. chewing. "mechanical digestion" digestion--> breaking down into smaller molecules that can be absorbed Movement of nutrients from lumen-->blood stream elimination--> products that dont get digested. The digestive system does not create waste per say only bile. the bulk of feces is undigested material. |
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Stomach |
mechanical digestion. Mashes food up into a thick viscous solution. also chemically breaks things down. Secretes acid, kills alot of microbes. enzymes in the stomach break down large proteins only. |
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small intestine |
-continued mechanical break down -mixes in different enzymes breaks down fats, carbs, and proteins -absorption happens here |
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large intestine |
mostly water absorption, produces literal poop. |
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bile |
breaks down lipids. |
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pancreatic secretions |
breaks down carbs and proteins. Adds sodium bicarbonate instantly to neutralize stomach acid pH. pH in intestine is basic |
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extracellular digestion |
digestion in an extracellular body cavity such as the lumen of the stomach or intestines. |
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intracellular digestion |
food particles are taken in to specialized cells prior to digestion and digestion occurs within the cell (sponges, molluscs) |
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enteric system |
neurons that line the gut. |
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submucosal plexus |
controls glandular secretions and muscular contractions |
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myenteric plexus |
controls peristalsis and contractions of the muscularis externa (layer of smooth muscle that lines the digestive system.) |
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peristalsis |
pushed material along the digestive tract. also the back and forth motion mixes the food. the motion is back and forth and is not unidirectional. |
