Question | Answer |
neuronal vs. hx communication | neuronal - rapid and direct
hx - slower and non-specific and long-lasting |
Paracrine system | local mediators (px a.a. or f.a. derivatives) released into interstitial fluid --> NOT HORMONES |
Give example of hx from paracrine system and what does it do | prostaglandins - smooth muscle contraction, inflammation |
Why is paracrine system different than endocrine system? | hx are not produced at discrete site but in many places in body |
What are nx dependent upon for energy? Does it depend on insulin to get glucose? | -glucose and aerobic respiration (no glycogen)
-no |
Where does action potential originate? | axon hillock |
What is sodium / potassium pump? | pump 3 Na+ out for 2 K+ in |
When do voltage-gated K channels start to open? | When Na+ channels start to close |
When is the cell at a resting potential? | when rate of Na+ passively diffusing back into cell = rate being pumped out |
Is the Na/K pump ever NOT working? | NO |
Is electrical synapse bidirectional / unidirectional and where can it be found? | -bidirectional
-cardiac muscle and visceral smooth muscle |
Is chemical synapse bi/uni directional and where can it be found? | -unidirectional
-motor end plate (connect nx with muscle) |
Brownian motion | random motion of molecules |
What is slowest step in transferring nervous signal? | Ca2+ mediated ntm release |
Does ntm enter postsynaptic cell? | NO --> ntm attaches to rx and postsynaptic mem becomes more permeable to ions or acts via 2nd messenger |
How to get rid of enzyme (3)? | 1.) enzyme destroy
2. presynpatic recycling
3. diffuse out |
Can a synapse release more than one ntm and both excite/inhibit? | NO |
Can a single ntm both inhibit and excite? | YES |
How does AcH act on heart vs. smooth muscle of intestine? | inhibitory / excitatory |
Neuroglia? | capable of cx division and can multiply to fill space caused by brain injury |
Microglia & oligodendrocytes | -phagocytize microbes and debris in CNS
-create myelin sheaths (only found in vertbrates) in CNS |
Where are sensory/afferent nx located? Motor/efferent nx? | dorsally (back)
ventrally (front) |
2 divisions of nervous system and what are they? | -CNS-brain and spinal cord
-PNS-everything outside of brain and spinal cord / connects CNS to limbs and organs |
What does PNS break into and what are they controlled by? Where do they receive signal from? | -Somatic nervous system (voluntary)
-autonomic nervous system (involuntary - controlled by hypothalamus) |
What does ANS break into? | -parasympathetic (rest and digest)
-sympathetic (flight or fight) |
Nucleus vs. ganglion | cell bodies located in CNS vs. cell bodies located outside CNS |
postganglionic sympathetic nx. vs. postsympathetic paras. nx. | lie far from effectors vs. lie near effectors |
Somatic nervous system
1. Once nerve fibers leave CNS, synapse where?
2. What does it release?
3. What does it innervate?
4. Excitation / inhibition | 1. Once nerve fibers leave CNS, don't make synapse till effector organ
2. release AcH
3. innervates skeletal muscle
4. excitation |
Autonomic nervous system
1. Once nerve fibers leave CNS, synapse where?
2. What does it release in preganglionic? Postganglionic?
3. What does it innervate?
4. Excitation / inhibition | 1. nerve fibers leaving CNS synapse with ganglion before effector organ
2. preganglionic PNS and sympathetic both release AcH
---> postganglionic para. : AcH
---> postganglionic sympathetic: Norepi / epi
3. glands, smooth and cardiac muscle
4. both |
AcH is used in? Norepi / epi is used in? | -SNS and PNS
-SNS only |
Where are internx mostly found? Sensory and motor nx? | CNS
PNS |
Path of light once it strikes eye? | cornea --> aq. humor--> pupil --> lens --> vitreous humor --> retina |
Where does light bend most when it enters eye? | Cornea = refractive index of 1.4 |
How does iris regulate amount of light that enters eye? | ciliary muscle |
What happens when ciliary muscle contracts? Relaxes? (circle opening, shape of lens, focal point) | -circle opening decreases, lens more spherical, bring focal point closer to lens
-lens flattens, increase focal distance, circle opening increases |
What type of lens is eye? | -converging/convex --> real and inverted image
-object must be outside focal distance |
Fovea and what is it made of? | mostly cones and most accurate vision |
What are rods made of? What happens when light strikes rods? | -rhodopsin
-photon strikes retinal in rhodopsin, causes hyperpolarization, transduced into neural signal to brain |
What is the precursor for all pigments in rods and cones? | vitamin A |
Process of sound waves from start --> mvmt of fluid in cochlea. | hit pinna - vibrate tympanic ear drum - vibrate middle ear bones (MIS) - vibrate oval window - mvmt fluid in cochlea |
What happens once cochlea fluid moved? | -vibration of basilar mem
-stereocili microvilli "hair" cx bend in organ of corti
-influex of K+ --> voltage positive
-Ap generated in auditory nerve
-AP relayed to brain --> hearing! |
Why is oval window smaller than tympanic membrane? | -to increase pressure
-greater force required to transfer sound from air to perilymph |
Semicircular canals | -sense position and mvmt of head
-balance
-3 are perpendicular to each other |
endocrine vs. exocrine | -endocrine-release hx into env't through ducts
-exocrine-release sweat, oil, enzymes directly into body fluids |
What do hx ABSOLUTELY need? | receptors! |
What are 3 basic types of hormones and how do they act? | -peptide (2nd messenger)
-steroid (nuclear rx)
-tyrosine (nuclear rx) |
Where are all peptide hx made? | -preprohx (rough ER) --> prohx (ER lumen) --> hx (Golgi) |
Whether it be ntm or protein hx, what happens when it attaches to rx? | 1. opens ion channels
2. activates 2nd messenger |
Is 2nd messenger ALWAYS excitatory? | no |
Where do steroid hx come from? | adrenal cortex, gonads, placenta |
What are major types of tyrosine derivatives? | -T3 and T4
-catecholamines from adrenal medulla |
What kind of hx are catecholamines? | -px and act through 2nd messenger cAMP |
What controls pituitary glands? | hypothalamus |
What do steroid hx cause? | promotes transcription of specific genes |
Do a.a. hx or steroid hx have longer-lasting actions? | steroid hx |
What terminates cAMP action? | phosphodiesterase |
What hx are ovaries under control of? | GNRH --> LH and FSH |
Diabetes mellitus vs. diabetes insipidus | -mellitus-lack of insulin or resistance to it
-insipidus-kidneys unable to conserve water (defect in secretion of ADH) |
Diabetics have (2) sx related to insipidus and mellitus. | 1. polyuria - increased urination
2. polydipsia - increased thirst |
2 types of diabetes mellitus | Type I (insulin-dependent)
-autoimmune destruction of beta cells
Type II (non-insulin dependent)
-body resists effects of insulin
-most common |
Where is somatostatin made? What does it do? | stomach, intestines, and pancreas
-inhibit GH, insulin, and glucagon
-decrease rate of gastric emptying to extend time nutrients are absorbed |
How is bile released into duodenum? | bile stored in gall bladder joins with common bile duct --> joins pancreatic duct --> duodenum |
What are 3 types of cells found in pancreas? | -alpha (glucagon)
-beta (insulin)
-delta (somatostatin) |
What else can increase plasma glucose besides insulin? | glucocorticoids, epi, and growth hx |
Can insulin and glucagon enter cells? | NO |
Are nx in brain affected by insulin? | NO |
Where are adrenal glands located and what are they separated into? | -top of kidneys
-adrenal cortex and adrenal medulla |
What does adrenal cortex secrete? | -corticosteroids (steroid hx)
-sugar, salt, sex
-glucocorticoids, mineralocorticoids, cortical sex hx |
What does glucocorticoid do and what is major type? | -cortisol
-increase blood glucose conc and decrease protein synthesis |
What does mineralocorticoid do and what is major type? | -aldosterone
-reabsorbs sodium, secretes K+ and H+ to increase BP by acting on distal convoluted tubuel |
What does cortical sex hx do in males and females ? | -make androgen
-masculanizing effects in female |
What does adrenal medulla make? | norepinephrine and epinephrine (catecholamines = protein hx)
--> tyrosine derivatives (D--> N --> E) |
How does (nor)epinephrine act on internal organs and skin? On skeletal muscle? | -vasoconstrictors
-vasodilators |
What stimulates aldosterone and increases BP via vasoconstriction? | angiotensin II |
What does parathyroid hx do in kidney, gut, and bone? | -decrease excretion of calcium through kidney, increase secretion of phosphate
-increase absorption of calcium in gut
--> activate Vitamin D and excrete K+
-increase bone resorption and recruitment of osteoclasts |
How does PTH act on osteoclasts? | -PTH acts on osteoblasts which produces RANKL to stimulate osteoclasts |
PTH _____ calcium levels, calcitonin ____calcium levels | -increase and decrease |
2 major roles for thyroid gland | -set metabolic rate
-calcium homeostasis |
What kind of hx are T3 and T4 and what do they do? | -nuclear hx
-increase basal metabolic rate and increase cx respiration |
hypothyroidism and sx | -deficiency of iodine and decreased thyroid hx
-lethargy and low metabolism |
hyperthyroidism and sx | -tumor / thyroid over-stimulation
-over activity |
goiter | enlarged thyroid as result of hypo/hyperthyroidsm |
calcitonin actions on kidney, gut, bone | -increase excretion of calcium from kidneys
-decreases absorption from gut
-decreases osteoclast activity and increases storage in bone |
Main fxns of calcium | -bone
-muscle contraction
-normal blood clotting co-factor
-cell mvmt and ntm release |
anterior pit hx are ____ and ____ | -direct-act directly by binding to rx
-tropic - bind to rx and cause release of effector hx |
direct hx | Prolactin
Endorphins
Growth hx |
where does growth occur in bones? | epiphyseal plates of long bones |
Tropic Hx | FSH
LH
ACTH
TSH |
ACTH | -adrenocorticotroic hx
-stimulates adrenal cortex to release glucocorticoids via cAMP |
What stimulates adrenal medulla? | sympathetic and parasympathetic activity |
Hx of posterior pituitary | -oxytocin - milk ejection and uterine contractions
-ADH - aka vasopressin and causes collecting ducts of kidney to become permeable to water |
What is ADH secreted in response to? (brain receptors) | -osmoreceptors - increased blood osmolarity
-baroreceptors - decreased blood volume |
Prolactin is released in absence of_______ | prolactin inhibiting factor |
What do coffee and beer affect in renal system? | block ADH --> increase urine volume |
Why isn't prolactin produced before birth? What does lactation block? | -inhibitory effects of P and E
-menstrual cycle |
Where do most synapses occur? | on dendrites |
Does the cell body of a neuron have a nucleus and organelles? | YES! |
Myelin sheath and why is it a good insulator? | -covers axon intermittently with nodes of Ranvier gaps
-fatty and has no channels |
Schwann cells | makes myelin sheath in the peripheral nervous system by wrapping around axon |
Schwan cx vs. oligodendrocytes | -Schwann cx act in peripheral nervous system
-oligodendrocytes act in central nervous system |
What is benefit of saltatory conduction? | speeds up AP conduction in axon |
Axodendritic synapse | axon terminal --> dendrite |
Axosomatic synapse | axon terminal --> cx body |
Axoaxonic synapse | axon terminal --> axon hillock |
Brief summary of ntm --> ATP | ntm leaves presynaptic through vesicles triggered by calcium, binds to rx, opens up channel on postsynaptic that causes change in mem potential |
Examples of ntm | ATP, AcH, NE, dopamine |
What are synaptic knobs? | another name for axon terminal |
What causes fatigue in a nx? | continous synaptic activity --> depletion of ntm --> fatigue |
Defining characteristic of AP | all or nothing! |
What does the resting mem potential hope to achieve? | negative inside, positive outside / sodium outside, potassium inside |
How does resting mem potential achieve negative inside? | Na/K pump and K channel leakage |
What happens during depolarization? | sodium channels open and positive sodium rushes inside |
What happens during repolarization? | potassium channels open and sodium channels close , potassium rushes outside |
What happens during hyperpolarization? | K channels don't close fast enough so mem potential drops below |
When does absolute refractory period occur? Relative refractory period? | -depolarization to cx re-establish original resting state
-after hyperpolarization till resting state re-established |
What does "all-or-none" mean? | All AP have the same magnitude NO MATTER WHAT |
excitatory synapse | ntm binding causes postsynaptic potential to be more positive (depolarization) --> AP |
inhibitory synapse | ntm binding causes postsynaptic potential to be more negative (hyperpolarization) |
Endocrine vs. exocrine | -endocrine - hx, no duct, acts long distances
-exocrine - non-hx secretion into ducts |
What does pineal gland make? | melatonin |
What does thyroid gland make? | thyroid hx and calcitonin |
What does adrenal gland make? | -medulla - epi and norepi
-cortex - mineralocorticoids / glucocorticoids |
What does dopamine inhibit? | prolactin |
Where is aldosterone made? | adrenal cortex |
Parathyroid vs. calcitonin | parathyroid increases bone resorption while calcitonin puts calcium back in |
What does thymus do? | stimulates T-cx to develop |
What is major type of glucocorticoid? | cortisol --> increase blood sugar |
Does ovary make testosterone? | small amount |
What is the result of diabetes? | -glucose can't enter cx --> high blood sugar
-cx starved of sugar --> f.a. metabolism |
What does f.a. metabolism in diabetes result in? | ketone bodies --> ketoacidosis (acidic blood) |
Why do diabetes pee more? | sugar in urine leads to more water in urine from osmosis |
gigantism | too much GH during growing age --> well-proportioned giants |
acromegaly | too much GH later on in life --> disproportioned growth of certain areas of body that still respond to GH |
The major types of hx are ______ and steroids | a.a. |
cAMP path | a.a. binds mem rx, G-px, adenylate cyclase activated, cAMP made, protein kinase cascade |
What types of hx can go directly into cx? Where does it bind? | -steroid and thyroid hx
-binds rx in cytoplasm or nucleus |
Phospholipid path | a.a. binds mem rx, G-px, phospholipase C activated, mem phospholipid split into DAG and IP3
-DAG triggers px kinase cascade
-IP3 releases Ca from the ER |
What creates specificity of hx for target cx? | whether or not there are rx for hx |
Humoral control of hx | glands directly respond to chemical levels in the blood
-parathyroid and low Ca |
Neural control of hx | glands release hx when stimulated by nerves
-flight or fight |
Hormonal control of hx | glands release hx when stimulated by other hx
-tropic hx |
Sensory = __________.
Motor = ___________. | -afferent to CNS
-efferent away from CNS |
Sympathetic is ________.
Parasympathetic is ______. | -flight or fight
-rest and digest |
Examples of positive feedback. | -LH and estrogen surge
-oxytocin and contractions
-blood clotting platelets |
What is reflex arc? | receptor - sensory nx - integration center - motor nx - effector |
Why do reflexes bypass the brain? | creates faster response
-brain still aware of what is happening |
monosynaptic vs. polysynaptic | -monosynaptic - no internx / direct synapse of sensory to motor
-polysynaptic - internx present |
During knee jerk, the ____ is contracted and the ______ is relaxed. | -extensor
-flexor |
What does the golgi tendon reflex protect? | protects muscle from heavy loads by causing muscle to relax and drop the load |
What happens during the golgi tendon reflex? | nx from golgi tendon organ fires, motor nx inhibited, muscle relaxes, load dropped |
What is role of spinal cord in reflex arc? | provides synapse(s) for reflex arc |
What does efferent control refer to in reflex arc? | brain can still override spinal reflexes |
Where in the skin are the touch, heat, and pain rx located? Pressure rx? | -close to surface near dermis-epidermis boundary
-deeper in dermis |
Proprioreceptor | -senses position of a body part
-controlled by cerebellum |
What do thermoreceptors detect? | A CHANGE in temperature |
Olfaction process | chemicals enter nose, trapped in mucus, picked up by mem rx on cilia, cx depolarization |
Taste process | Chemical dissolve in saliva, carried inside taste bud, microvilli pick up chemicals, release ntm to brain |
What are inner ear bones? | malleus(hammer) , incus (anvil) , stapes (stirrup) |
What is the ear drum? | tympanic membrane |
What is vestibule in hear? | contacts oval window and continuous with semicircular canals
--> balance |
What is main fxn of cochlea? | propagates sound pressure waves in fluid and transduces them into nerve impulses sent to brain |
Which is more sensitive: rods or cones? | rods |
What is importance of rhodopsin and what is it made of? | -chemical responsible for light reception
-retinal + opsin |
Light converts ____(cis/trans) retinal --> _____(cis/trans) retinal | cis --> trans |
What is blind spot? | Where bundle of nerves exist in back of retina that sends signal to brain |
How does brain create 3D image? | combines 2 images from each eye (also to get rid of blind spot) |
How many nx do the sympathetic and parasympathetic system rely on? | 2 |
Describe the nx in a sympathetic nervous system. | short preganglionic and long postganglionic |
Describe nx in a parasympathetic n.s. | long preganglionic and short postganglionic |
Where is oxytocin and ADH produced? | hypothalamus |
What is aldosterone produced in response to? | low sodium or elevated potassium |
Which division of autonomic nervous system has dominant effect on heart? | parasympathetic nervous system |
How is the GI tract an endocrine gland? | secretes secretin, CCK, gastrin |
How are kidneys an endocrine gland? | secrete erythropoietin to stimulate bone marrow to make RBC |
How is heart an endocrine gland? | secretes ANP to regulate salt and water balance |
How is thymus an endocrine gland? | secretes thymosin to regulate proper T-cx differentiation |
Totipotent cx | any one of these cx could make complete organism |
What is special about a morula? | has totipotent cx |
blastula vs. blastocyst | blastocyst is mammalian blastula type |
blastocoel | hollow, fluid-filled cavity |
trophoblast | surrounds blastocoel and makes chorion and placenta |
inner cx mass | makes actual organism |
Which occurs first, determination or differentiation? | determination |
Where is the adrenal cortex formed from? | mesoderm |
Where is the adrenal medulla formed from? | ectoderm |
Deuterosome vs. protosome | -deuterosome = human
-protosome = everything else |
What does the blastopore become in deuterosomes vs. protosomes? | -deuterosome = anus
-protosome = mouth |
What does archenteron develop into? | gut |
What do neural crest cx form? | peripheral nervous system |
umbilical arteries | carry deoxygenated blood away from fetus |
umbilical veins | carry oxygeanted blood towards fetus |
ductus venosus | -shunts 1/2 of oxygenated blood from umbilical vein to inferior vena cava
-bypass nonfxnal liver
-preferentially give oxygenated blood to brain |
foramen ovale | connects right and left atria |
ductus arteriosus | connects pulmonary artery --> aorta
-bypasses nonfxnal lungs |
Why does sympathetic system produce more whole-body response? | ganglia are connected to each other |
What are trophic hx? | stimulate other glands to secrete hx |
When Na/K pump is blocked, what will be intracx conditions? | -increase in intracx sodium
-decrease in intracx K |
When Na/K pump is blocked, what also is blocked? | ATP consumption |
What are 3 major px in plasm? | albumin, gammaglobulins (antibodies, fibrinogen |
Secondary px structure | alpha helix or beta sheet |
What are the 2 major systems that maintain homeostasis? | endocrine and nervous system |
What are the parts of a pancreas? | head, neck, body, tail |
What does low Ca cause? | increases nx permeability to sodium --> hyperexcitability |
What stimulates osteoblasts? | calcitonin |
Small intestine: parathyroid vs. calcitonin | -parathyroid increases Ca absorption
-calcitonin decreases Ca absorption |
How does Vit D act on intestine? | increases Ca absorption |
What does shortage of insulin crease? | cause blood glucose level to increase and glycolysis to decrease |
What happens if there is a decrease in rate of glycolysis in relation to ketone bodies? | -forces body to metabolize fat --> ATP
-fat metabolism = ketone bodies |
What stimulates the release of estrogen? | LH |
Where are gap junctions found? | heart and smooth muscle |
What does thyroid hx stimulate? | px synthesis and activity of Na/K ATP ase |
What does atrial natiuretic peptide do? | decrease blood volume |
2 characteristics of cancer | -abnormal cell growth
-abnormally high conc. of product |
Calcitonin actions with Ca and P | 1. blocks bone resorption
2. inhibits renal absorption of Ca and P |
Parathyroid actions with Ca and P on bone, kidney, and s. intestine | -bone = releases Ca and P
-kidney = decreases excretion of Ca, increases P
-s. intestine = increases reabsorption of Ca and P |
Overall what does PTH do? | increases blood calcium, and decreases blood phosphate |
What hx is in excess with someone with high sugar level and muscle wasting? | excess cortisol |
What are the 4 hx that increase blood glucose levels? | glucagon, cortisol, GH and epi |
facilitated diffusion | relies on a channel px to move down a concentration gradient |
Does endocytosis depend on ATP? | yes |
What kind of gland is the salivary? | exocrine gland |
Which is stronger: ionic or covalent bond | ionic |
What are the tyrosin-deriv a.a.? | thyroid hx, epi, and norepi |
What are the steroid hx? | cortisol, aldo, progesterone, testosterone |
Where is AcH used? | -parasympathetic NS
-neuromuscular jxns to stimulate voluntary muscles |
What does the PNS and SNS both release? | acetylcholine at preganglionic nerve |
Does calcitonin increase phosphate reabsorption in kidneys? | NO |
If the Na/K pump was not working, what would be the conditions? | built up of Na inside, built up of K outside |