Term
| What is converging evolution? |
|
Definition
| when two different animals come up with body systems that do exactly the same job. The system looks, at least superficially, exactly the same as each other. |
|
|
Term
| Sponges are a part of what animal phyla? What is its special features? |
|
Definition
|
|
Term
| insects, arachnids and crustaceans are a part of what phyla? What are some of their important characteristsics? |
|
Definition
arthropoda
They have exoskeletons and are ecdysozoans --> IE they molt. |
|
|
Term
| sea stars and sea urchins are a part of what phyla? What are some of their specific traits? |
|
Definition
|
|
Term
| squids are a part of what phyla? |
|
Definition
|
|
Term
| snails, clams and squids are a part of what phyla? |
|
Definition
|
|
Term
| segmented worms are a part of what phyla? |
|
Definition
|
|
Term
| What is special about porifera's body structure? |
|
Definition
| Porifera - or sponges - posess no true tissues. |
|
|
Term
| What are the two major strategies to deal with environmental variables? |
|
Definition
Conforming - allow physiology to fluctuate with the environment (doesnt use energy)
Regulating - maintain physiology different from environment. (ATP) |
|
|
Term
|
Definition
| Organisms that let their bodies water and salt composition drift and change with their environment. |
|
|
Term
|
Definition
| organisms that rely on the temperature outside of their body to determine their own body temperature. |
|
|
Term
|
Definition
| Body temperature is maintained internally and is substantially different from the environment. |
|
|
Term
|
Definition
| Organisms that maintain water and salt concentrations different from the environment. **it's body has high salt concentrations relative to the exterior and so its tissues are flooded with water often. Kidneys or other mechanisms are required in order to eject the excess water. |
|
|
Term
| How do organisms cope with environmental changes over the short term and over the long term? |
|
Definition
over the short term organisms adapt through homeostasis
over the long term organisms adapt through evolution. |
|
|
Term
|
Definition
Homeostasis is the regulation of bodily (internal) environment at or near a stable level.
IE regulates a physiological variable relative to a set point
requires large amount of energy |
|
|
Term
| what are the goals of homeostatic mechanisms? |
|
Definition
| to minimize the changes inside the body relative to the drastic changes outside of it. |
|
|
Term
| in Homeostasis, what is the 'set point'? |
|
Definition
the set point is the ideal value for that variable.
for example: 38C is the ideal temperature point for humans |
|
|
Term
| what are the different catagories of responses that are used in homeostasis? |
|
Definition
Negative Feedback
Positive Feedback
Feed Forward |
|
|
Term
| What is negative feedback? |
|
Definition
Response that moves the variable towards the set point.
IE it MINIMIZES the differences between the actual level and the set point. |
|
|
Term
| what are the stages in a homeostatic response? |
|
Definition
Homeostatic challenge
input from sensory organ
integration of sensory impulse
to effector within body
Response. |
|
|
Term
| What two phases are often seen within a feedback loop? |
|
Definition
| Often there will be a feedback loop with something that stimulates and something that inhibits a response. |
|
|
Term
| A disruption of the usual negative feedback response in the thyroid gland results in what disease? What is the disease characterized by? What causes this to occur? |
|
Definition
Goiter
it is characterized by the over-stimulation of the thyroid gland due to excess TSH in the blood. causes an enlarged thyroid
It is caused by reduced iodine levels because the hormones T3 and T4 require iodine to be attached in order to be activated. |
|
|
Term
| Explain the negative feedback loop involving iodine intake and the thyroid gland. Why is iodine an important facet? |
|
Definition
The hypothalamus receives stimulus that there is not enough of the metabolic hormones T3 (which turns into T4 when activated)and T4. It sends out the "thyroid regulating hormone" (TRH) to the anterior pituitary gland, which then sends out the "thyroid stimulating hormone" (TSH) to the thyroid gland which then produced T3 and T4 if excess iodine is available.
If no iodine is available, excess TSH is produced and the thyroid becomes enlarged from over-stimulation (goiter) |
|
|
Term
| what is the limiting factor in the thyroids production of T3 and T4 hormones? |
|
Definition
| iodine is the limiting co-factor. T3 and T4 are not produced in instances of low blood-iodine concentrations. |
|
|
Term
| Negative feedback loops are often mediated by what type of molecule? |
|
Definition
|
|
Term
| What is positive feedback? |
|
Definition
Positive feedback moves a variable away from a set point.
IE it amplifies the difference between the actual level and the set point.
can occur in stimulation or inhibition. |
|
|
Term
| When would your body use positive feedback? |
|
Definition
| Instances where you need to accelerate a reaction, quickly increase/decrease a process. |
|
|
Term
| What stops positive feedback from continuing indefinitely? |
|
Definition
| negative feedback eventually shuts of the amplification effect of positive feedback. |
|
|
Term
| The release of oxytocin during labour is an example of what type of feedback? |
|
Definition
positive feedback.
1) baby sends signals to uterus and causes it to start contracting.
2) contractions are sensed by stretch sensory receptors in the uterine walls and they send that info to the posterior pituitary gland
3) the posterior pituitary gland releases oxytocin into the blood, which makes the uterus more sensitive to contractions. (stimulating further contractions)
--> the more the uterus contracts, the more signals are sent to the brain, the more the posterior pituitary gland releases oxytocin, the more the contractions are initiated. |
|
|
Term
| Explain the process of oxytocin release in labour, and what does it do? What type of feed back is this? |
|
Definition
1) baby sends signals to uterus and causes it to start contracting.
2) contractions are sensed by stretch sensory receptors in the uterine walls and they send that info to the posterior pituitary gland
3) the posterior pituitary gland releases oxytocin into the blood, which makes the uterus more sensitive to contractions. (stimulating further contractions)
--> the more the uterus contracts, the more signals are sent to the brain, the more the posterior pituitary gland releases oxytocin, the more the contractions are initiated.
positive feedback. |
|
|
Term
| Oxytocin is what? what does it do? |
|
Definition
| Oxytocin is a hormone secreted during labour and during milk let-down. |
|
|
Term
|
Definition
| false labour, but in reality its the initiation of the positive feedback response that leads to labour. |
|
|
Term
| What does the nervous system modify in order to communicate a change in signal? |
|
Definition
| through the changing of amplitude and/or frequency of the signals. |
|
|
Term
| The rising phase of nerve action-potential is what type of feedback? |
|
Definition
|
|
Term
| what is "feedforward"? When is it used? |
|
Definition
Feedforward is a type of response wherein the future needs are anticipated and physiology is adjusted in advance for that need.
*often involves learning and complex behaviors (equestrian example) though some can be instinctual (multi-generational migration of the monarchs) |
|
|
Term
| Explain what happens during a fever and when/where positive/negative feedbacks or feed forward occurs |
|
Definition
*Variant between cold chills and feelings of being hot.
1) chills part of reaction:
pyrogen changes the set point for temperature to higher than regular, initating a positive feedback response that attempts to raise your temperature quickly through shivering.
2) positive feedback overshoots the new set point and causes negative feedback to initiate in the form of sweating.
this continues until the pyrogens are dead and the set point returns to normal.
*going to get a blanket would be considered feeding forward. |
|
|
Term
| Nervous systems are found in all animals except for which? |
|
Definition
|
|
Term
| What are the two major systems involved in the coordination and regulation of animal body systems? |
|
Definition
| the endocrine system and the nervous system |
|
|
Term
| What are the major roles of the nervous system? |
|
Definition
1) collects information
- internally/externally
- using modified neurons (sensory receptors)
2) process and integrates information
- evaluates based on past experiences/genetics
3) transmit information
- coordinates / regulates effector organs/cells |
|
|
Term
| An impulse going away from the brain is called a _______ impulse. |
|
Definition
Efferent.
Or motor impulse |
|
|
Term
| An impulse going towards the brain from a sensory organ is called an _______ impulse |
|
Definition
afferent impulse
or sensory impulse |
|
|
Term
|
Definition
| synthesis of an output based on the sum of the inputs. |
|
|
Term
| multiple sclerosis is characterized by a problem with what? |
|
Definition
| a problem with a specific type (shwann cell) of glial cells. |
|
|
Term
| where is the action potential initiated on a neuron? |
|
Definition
| at the axon hillock, also known as the spike initiation zone |
|
|
Term
| explain the structure of a neuron, beginning at the dendrites. |
|
Definition
| dendrites ->> cell body (soma) --> axon hillock / spike initiation zone --> axon (surounded by the myelin sheath, which is schwann cells wrapped around the axon) --> terminal branches |
|
|
Term
|
Definition
|
|
Term
|
Definition
| a bundle of axons (a few to millions) |
|
|
Term
|
Definition
| An axon is also called a nerve fibre. Nerve impulses are propagated along axons. |
|
|
Term
|
Definition
| A synpase is a connection between an axon terminal and an effector cell |
|
|
Term
|
Definition
| can be a neruon, muscle cell or any other type of cell. Efferent impulses lead to the effector cells. |
|
|
Term
| What does sensory input and motor output depend on? |
|
Definition
|
|
Term
| What is membrane potential? |
|
Definition
| the unequal distribution of charge across a {cell} membrane measured in mV |
|
|
Term
| the inside of a cell has what charge relative to the outside of a cell? |
|
Definition
| negatively charged relative to the outside of a cell |
|
|
Term
| What is action potential? |
|
Definition
| fairly large, rapid change in membrane potential over a short time frame. |
|
|
Term
| What are the different types of membrane potentials? |
|
Definition
1) resting membrane potential (RMP)
2) Action potential (AP)
3) electrotonic potential (EP) |
|
|
Term
| What is the resting membrane potential about in neurons and muscle cells? (in mV) What contributes to this number? |
|
Definition
around -70 mV in muscle cells and neurons.
-10 mV = electrogenic pump (ATPase)
-5 mV = anionic proteins
-55 mV = potassium channels create current that generates the -55 mV. Positive charge flows to the outside of the cell. |
|
|
Term
| What principle ions are involved in resting membrane potentials? |
|
Definition
inorganic ions: Potassium (K) and Sodium (Na)
Anions found in macromolecules inside cell contribute to internal negativity. |
|
|
Term
| Where is the highest concentration of sodium and potassium found, relative to the interior/exterior of a cell? |
|
Definition
Sodium is found in high concentrations outside the cell
potassium is found in high concentrations inside the cell |
|
|
Term
| How are the ion gradients maintained? Describe the mechanism? |
|
Definition
Through active transport Sodium/Potassium ATPase ...
The pump uses ATP to move 3 sodium molecules out of the cell while bringing 2 potassium molecules into the cell. |
|
|
Term
| The pump, sodium/potassium ATPase is also known as what type of pump |
|
Definition
| and electrogenic pump - that is it creates an electropotential |
|
|
Term
| What different types of channels are there? What makes them differ? |
|
Definition
Leak Channels --> channels that are always open. Responsible for resting potential.
Voltage regulated channels -=> often found in neurons and responsible for action potential.
Mechanically gated channels --> opened by the binding of a ligand. |
|
|
Term
| what is electrotonic potential? |
|
Definition
small (few mV) current (ions) traveling along the SURFACE of a membrane.
can depolarize or hyperpolarize a cell but can only travel a short distance across the membrane
used to initiate AP at axon hillock + to conduct AP along axon (except for where schwann cells are) |
|
|
Term
| Describe the special features of action potentials |
|
Definition
depolarizes the membrane from -70mV to 'round +35 mV
- is all or nothing but transient [turned on than off]
- once started is conducted along the entire axon
- relies on ion currents through membrane via voltage-gated ion channels (found in the space between glial {schwann} cells on the axon) |
|
|
Term
| What are the stages in action potential? |
|
Definition
1)Leading up to threshold potential
2) reaching threshold potential results in initiation of depolarization of membrane (Na+ voltage gated channels open, Na moves inwards)
3) Action Potential (sodium channels close)
4) repolarization of membrane occurs (ATPase, potassium leak channels)
5) hyperpolarization occurs (overshoot) (potassium leak channels)
6) resting potential |
|
|
Term
| Explain the hodgkin-huxley cycle |
|
Definition
A type of positive feedback response
occurs during the rising phase of the nerve action potential
1) membrane depolarizes to threshold, opens some voltage-regulated Na+ channels
2) further depolarizes membrane, opens more voltage-regulated Na+ channels,
3) further depolarizes membrane...repeat
**accelerates depolarization of membrane. |
|
|
Term
| What is the refractory period? |
|
Definition
| the period where a new action potential cannot be generated. |
|
|
Term
| What keeps electrotonic potentials from flowing backwards during action potential propagation? |
|
Definition
| the refractory period and hyperpolarization keeps the electrotonic potential from propagating backwards. |
|
|
Term
| In which ways can conduction velocity be increased? |
|
Definition
by increasing the diameter of the nerve axon (cable properties)
- insulating the axon with myelin sheath (reducing the need for electrotonic potentials across the axon membrane) |
|
|
Term
| How is an action potential propagated down an axon with a myelin sheath? What is this called? |
|
Definition
Electrotonic potentials jumps skips the glial cells and jumps from Node of Ranvier to node of ranvier.
Voltage regulated channels are concentrated at the nodes of Ranvier and so AP is generated only at the nodes.
this is called saltatory conduction |
|
|
Term
| What is saltatory conduction? |
|
Definition
| AP conduction along a myelin sheathed axon. electrotonic potential flows from node (of ranvier) to node and so AP jumps from node to node, increasing conduction velocity. |
|
|
Term
| What separates neurons and how do signals get from one neuron to another? |
|
Definition
neurons are separated by synaptic clefts (the synapse = space between)
two types of synaptic transmission:
1) electrical (ions flow from cell to cell via gap junctions)
2) chemical (another molecule carries signal) (most often used)
- neurotransmitters from presynaptic cell |
|
|
Term
| What are the different types of synaptic transmission? |
|
Definition
Electrical - ions flow directly from cell to cell through gap junctions. Example: cardiac muscle cells
Chemical - neurotransmitters are released into the synaptic cleft from vesicles in the presynaptic cell |
|
|
Term
| What forms the synaptic vesicles tht contain neurotransmitters? |
|
Definition
|
|
Term
| What functions does acetylcholine have? |
|
Definition
CNS: stimulates brain; important in memory, muscle control
PNS: stimulates skeletal muscles at neurotransmitter junction via a "nicotinic receptor"**,
inhibits cardiac muscle contraction via muscarinic receptor**, promotes digestion |
|
|
Term
| epinephrine and norepinephrine are examples of what? What are their functions? |
|
Definition
of biogenic amine neurotransmitters
______----_____missing stuff |
|
|
Term
| What are the classes of receptor proteins? describe them |
|
Definition
Ionotropic receptors (e.g. nicotinic receptor) - ionotropic receptors funcation as ion channels themselves
-> ligand-gated ion channels
Metabotropic receptors (muscarinic receptors) - usually have g-protein binding sites on interior face of cell that act through secondary messengers to alter some aspect of cellular metabolism. (not a channel protein.) |
|
|
Term
| The nicotinic receptor is what type of receptor? What does it do? |
|
Definition
it is an ionotropic receptor.
it acts as a sodium (Na+) channel when a ligand binds to it. |
|
|
Term
| Depolarization is inhibitory or stimulatory? |
|
Definition
|
|
Term
| Explain the steps in chemical transmission at the point of the synapse. |
|
Definition
AP opens voltage gated Ca2+ channels, Ca++ rushes into cytosol.
Ca++ binds to vesicles and causes them to fuse with pre-synaptic membrane, which releases neurotransmitters into the S cleft. (excytosis)
NT diffuse across the SC and bind to receptors in post-synaptic membrane.
Action potential, voltage rated calcium channels, calcium comes in, calcium binding to vesicles, exocytosis (vesicle bind to membrane), diffusion of products across synapse to post-synaptic cell. |
|
|
Term
| How are neurotransmitters removed from the synaptic cleft? |
|
Definition
enzymes can be present who break them down
diffusion away from cleft (lost NT)
some can be taken back up through endocytosis |
|
|
Term
| What is an electrotonic potential from dendrites called? |
|
Definition
| a post-synaptic potential (PSP) |
|
|
Term
| What is IPSP and what is EPSP? |
|
Definition
Forms of GRADED POTENTIAL.
IPSP - Inhibitory post-synaptic potential --> moves the membrane potential further away from threshold.
EPSP - excitatory post-synaptic potential --> moves membrane potential closer to threshold. Must be big enough to reach threshold or no action potential will be achieved. There can be several synapses putting NT, which can be added together to achieve the AP. |
|
|
Term
| What does the size of a post-synaptic potential depend on? |
|
Definition
| It depends on the amount of neurotransmitter that is released. This is caused by a stronger stimulus. |
|
|
Term
| What is spatial summation? |
|
Definition
| Temporal Summation over the space of the dendrite surface. Several EPSP's can be combined together to initiate an action potential if it gets to the threshold. |
|
|
Term
| A nerve impulse going to the brain from a sensory impulse is called what? |
|
Definition
| It is called an afferent impulse. |
|
|
Term
| A nerve impulse going to the motor units from the brain is called what? |
|
Definition
| It is called an efferent impulse. |
|
|
Term
| Describe the embryonic brain at 4 weeks from top to bottom? |
|
Definition
Forebrain
Midbrain
Hindbrain |
|
|
Term
| Describe the embryonic brain at 5 weeks old from top to bottom? |
|
Definition
telencephalon
diencephalon
mesencephalon
metencephalon
myelencephalon |
|
|
Term
| Explain the two cell model |
|
Definition
| Sensory receptor (like on an epithelial cell) makes contact with the dendrites of a neuron. |
|
|
Term
| What is a/the Pacinian Corpuscle? |
|
Definition
highly modified dendrites.
Respond to DEEP TOUCH. |
|
|
Term
| What is a/the Meissner's Corpuscle? |
|
Definition
highly modified dendrites.
Respond to LIGHT TOUCH. |
|
|
Term
| What are mechanoreceptors? |
|
Definition
| Sensory receptors that respond to mechanical deformation. |
|
|
Term
| What are thermoreceptors? |
|
Definition
| Temperature receptors that respond to cold and heat. |
|
|
Term
|
Definition
| sensory receptors that respond to pain (tissue damage) |
|
|
Term
| What are electromagnetic receptors? |
|
Definition
| Sensory receptors that respond to electrical and magnetic fields. Infrared and ultraviolet light. |
|
|
Term
| What are graded potentials? |
|
Definition
|
|
Term
| What is receptor potential? |
|
Definition
| Receptor potential = small flows of ion along the surface of a membrane. |
|
|
Term
| What are examples of mechanoreceptors? |
|
Definition
- detect relative position of body structures
- membrane has mechanically-gated Na+ channels
- deforming stimulus depolarizes membrane. |
|
|
Term
| What is a hair cell? (with regards to mechanoreceptors) |
|
Definition
| Receptor cell with stereocilia to detect fluid movements (air, water etc). called hair cells because of the stereocilia. Neurons without axons. |
|
|
Term
|
Definition
| Found in crustacians, used to find the position of the body relative to gravity. Contains statolith's that touch the membranes and signal which way the body is orientated. |
|
|
Term
|
Definition
| Found in every type of vertebrate group. Semicircular canals that work similarily to the statoliths in crustatians. |
|
|
Term
| What are the different examples of photoreceptors? What do they have in common? |
|
Definition
Eye Spots (cups) [2 cell system]
Compound Eyes [composed of ommatidia]
Camera Eyes [lens used to focus light]
- all use photopigment to transduce light energy into a bioelectric signal.
Those pigment cells send the afferent impulses. |
|
|
Term
| What are the photopigments? |
|
Definition
Retinal and an opsin.
Rhodopsin in rods and several kinds of opsins in cones. |
|
|
Term
| Where is visual information processed in the brain? |
|
Definition
| in the occipital lobe. Found at the back of the brain. |
|
|
Term
| Is the visual sensory stimulation (phototransduction) an example of stimulatory response or inhibitory response. |
|
Definition
It is an example of an inhibitory response.
Light hyperpolarizes the photoreceptor cell and as a result reduces the amount of neurotransmitter that is released between the receptor cell and post-synaptic cell.
Light hyperpolarizes |
|
|
Term
| What does the sympathetic division of the autonomic division do? |
|
Definition
It's the fight or flight response!
stimulates heartbeat/force of contraction
relaxes airways
inhibits digestion
stimulates release of glucose into blood |
|
|
Term
| which is the exception tissue or gland that isn't affected by both para- and sympathetic systems? |
|
Definition
|
|
Term
| The sympathetic system all integrates through what structure? |
|
Definition
the celiac ganglion.
Or chain of sympathetic ganglia. |
|
|
Term
| Is the sympathetic nervous system a one or two-cell system? |
|
Definition
| two cell system --> a preganglionic cell sends out a fiber, which is attached to postganglionic neuron, which then leads to the effector cell. |
|
|
Term
| Would you expect a widespread or narrow effect for neurons passing through ganglion |
|
Definition
| Where ganglion occur there tends to be near body-wide effects. |
|
|
Term
| Explain the neurotransmitter and receptor for preganglionic fibers of both divisions, postganglionic fibers of sympathetic divisions, postganglionic fibers of parasympathetic. |
|
Definition
Preganglionic fibers of both - acetylcholine/nicotinic receptors
postganglionic fibers (sympathetic) - norepinephrine/ adrenoreceptors
Postganglionic fibers (parasympathetic) - acetylcholine / muscarinic |
|
|
Term
| What does the parasympathetic division of the autonomic division do? |
|
Definition
*active when body energy stores are being conserved/restored
"rest and digest" system
stimulates digestive tract
inhibits heart rate |
|
|
Term
| What are the types of animal skeletons? |
|
Definition
Hydrostatic skeleton (Cnidaria/annelida)
Exoskeleton(arthropoda)... shed by ecdysis
Endoskeleton (chordata, echinodermata) |
|
|
Term
| What are the types of endoskeletons? |
|
Definition
In echinoderms: Calcium Carbonate and Protein Fibers *easily dissolves in acid
Calcium phosphate and protein fibers * more resistent to acid. Internal store of ca++ and phosphate. |
|
|
Term
| Explain the structure of a muscle from the smallest level to the largest. |
|
Definition
Actin and Myosin filaments = Myofibril within a muscle fiber
One muscle fiber (cell)
bundle of muscle fibers (cells)
bundled into muscles |
|
|
Term
| each muscle fiber is innervated by how many motor neurons? |
|
Definition
Each muscle fiber innervated by one motor neuron.
One motor neuron innervates a group of muscle fibers (motor unit) |
|
|
Term
| what does the strength of contraction depend on? |
|
Definition
| strength of contraction depends on motor unit recruitment. Higher number = stronger contraction. |
|
|
Term
| Which neurotransmitter causes the muscle action potential? |
|
Definition
acetylcholine causes a muscle action potential.
opens ligand gated channels when it binds to a nicotinic receptor. |
|
|
Term
| What is unique 'bout the muscle effector membrane? |
|
Definition
| There is extensive folding of the muscle plasma membrane at the muscle neuron junction. |
|
|
Term
| Explain the mechanism of the contraction of the muscle cell. |
|
Definition
Binding of acetylcholine (NT) opens the ligand gated channel, starting movement of Na+ inwards.
Signal sends inwards, towards where the actin/myosin are.
Signal is propagated inwards along T-tubules, opening and closing voltage-gated potassium and sodium channels.
T-tubule depolarization opens voltage-gated Ca++ channels in sarcoplasmic reticulum, releasing Ca++ into the sarcoplasm.
Calcium binds to troponin, causing tropomyosin to move away from the myosin binding sites.
cross-bridge binds to actin and generates a force. (power stroke)
ATP binds to myosin and causes detachment of cross-bridging. |
|
|
Term
| what energizes the myosin? |
|
Definition
the binding of ADP and P_i to myosin activates it.
the binding of ATP releases the myosin. |
|
|
Term
| Neural stimulation always does what to skeletal muscles? |
|
Definition
| always shortens skeletal muscles |
|
|
Term
| amines are derived from what amino acids? |
|
Definition
| either tyrosine or tryptophan |
|
|
Term
| What are the major classes of hormones? |
|
Definition
Amines
-> derived from tyrosine or tryptophan
--> thyroid hormones
---> WATER SOLUBLE
Proteins / peptides
Steroid hormones
-> derived from cholesterol
--> Lipid soluble |
|
|
Term
| which type of water-soluble hormone can be moved across the plasma membrane? |
|
Definition
| thyroid hormones (T3 and T4) |
|
|
Term
| What are synthetic pathways? |
|
Definition
| Synthetic pathways use enzymes to to modify structures through that pathway. |
|
|
Term
| which is the active and inactive form of the thyroid Tx glands? |
|
Definition
| T4 is converted into T3 by deiodinase in liver. |
|
|
Term
|
Definition
a type of hormone, adrenocorticotropic hormone. IE adrenal-cortex thyroid hormone.
It stimulates adrenal cortex to make glucocorticoids (example, cortisol) |
|
|
Term
| what is the hypothalamus' function? |
|
Definition
| to secrete hormones that either activate or inhibit the anterior pituitary gland. |
|
|
Term
| how does the body respond to stress? |
|
Definition
in one of two ways: acute or chronic responses.
acute: almost instant due to activation of sympathetic division.
chronic: delayed by few minutes due to activation of hypothalamo-pituitary-adrenal axis |
|
|
Term
| when sympathetic n.s. is maximally active, which hormones are secreted by the adrenal gland? |
|
Definition
| norepinepherine and epinepherine |
|
|
Term
| where is glucocorticoids released from? |
|
Definition
| glucocorticoid release stimulated by ACTH from anterior pituitary. |
|
|
Term
| What are the major actions of glucocorticoids in stress? |
|
Definition
* stimulate gluconeogenesis, releasing glucose into blood
* stimulate breakdown of triglycerides into fatty acids / glycerol
* inhibit sensitivity to insulin
*inhibit bone growth/formation
***stimulate lung maturation in the fetus |
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Term
| what is the type of glucocorticoid found in vertebrates other than humans, rodents and fish? |
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Definition
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Term
| what is the type of glucocorticoid found in humans, rodents and fish |
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Definition
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