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BMS 302- Unit 1
Question | Answer |
---|---|
physiology vs anatomy | functions vs morphology |
steady state | nutrients are being changed, but concentration remains constant |
homeostasis | relatively stable internal environment |
negative feedback | when an increase in the input of a system causes a decrease in the output of the system |
two primary control systems | endocrine, CNS |
effector example | furnace |
receptor= | sensor |
afferent neurons | to CNS |
efferent neurons | away from CNS |
effectors use... (6) | skeletal, smooth, cardiac, endocrine, exocrine |
most important parameter in rate of diffusion | concentration gradient |
diffusion | movement from higher to lower concentration |
resting membrane potential (mv) | -70 |
outside of the cell is | + |
inside of the cell is | - |
the resting cell membrane is permeable to | K+, Cl- |
the resting cell membrane is impermeable to | Na+, A- |
K+ and Cl- ions travel through | leakage channels |
K+ concentration gradient | inside to outside |
K+ electrical gradient | outside to inside |
Na+ concentration gradient | outside to inside |
Na+ electrical gradient | outside to inside |
A- electrical gradient | inside to outside |
Cl- electrical gradient | inside to outside |
Cl- chemical gradient | outside to inside |
A- chemical gradient | inside to outside |
weird chemical gradients | K+ and Cl- (get repelled by electrical gradients) |
all cells develop | resting membrane potentials (not excitability or conductivity) |
Na/K pump | 3 Na out, 2 K in (opposite of their chemical gradients) |
excitability | ability to form an action potential |
conductivity | ability to propagate action potentials |
what cells CONDUCT action potentials | neurons, cardiac, smooth, skeletal |
what cells are excitable? | nerve and muscle cells |
conduction velocity | rate at which action potential travels down a neuron |
polarization | separation of charge across the membrane |
depolarization | more negative to less negative; or negative to positive |
depolarization ion and type of channel | Na+ gated (in) |
repolarization ion and type of channel | K+ gated (out) |
absolute refractory period | no response |
relative refractory period | threshold is higher to create a response |
4 factors that influence conduction velocity | myelination, temperature, pharmacologic agents, diameter of the conducting fiber |
CNAP | (compound nerve action potential) sum of electrical activity occurring at any given time on the compound nerve |
greater concentration inside the cell | K+, A- |
greater concentration outside the cell | Na+, Cl- |
procaine | prevents Na+ gated channels from opening |
sarcolemma | plasma membrane of muscle cells |
sarcoplasm | cytoplasm of muscle cells |
T tubules | conducts action potential from surface to inside of muscle cells |
sarcoplasmic reticulum | ER of muscle cells (releases calcium ions) |
fiber | another name for cell when referring to muscle |
myofilament | elements of contraction; actin and myosin |
the movement of Ca++ from the S.R. is via | simple diffusion; passive transport |
three molecules that make up the actin myofibril | actin, tropomyosin, troponin |
calcium binds to? | troponin |
Which molecule moves when Ca++ binds to expose an active myosin binding site on the actin myofilament? | tropomyosin |
Before myosin can bind to the active actin binding site, it must be in a high energy state. What step is necessary to convert myosin to its high energy state so that it can attach to the myosin binding site on the actin molecule? | ATPase hydrolyzes ATP |
What events must occur before the myosin head detaches from the actin binding site during relaxation? | calcium pump puts Ca++ back into the sarcoplasmic reticulum (terminal cisterns); ATP binds to myosin to release actin/myosin interaction |
relative calcium concentrations in the muscle cell | sarcoplasm=least; sarcoplasmic reticulum=middle; extracellular= most |
latent period 8 steps | look in notes |
Muscles involved in "fine motor skills" will have _____ muscle fibers per motor unit | fewer |
syncytium | mass of cells functioning as a single unit |
peristalsis | propelling of food through the GI Tract |
segmentation | mixing and kneading of GI contents |
efferent neurons between the Central Nervous System and the effector in the Somatic Nervous System | one |
efferent neurons between the Central Nervous System and the effector in the Autonomic Nervous System is | two |
Ganglia are present between the Central Nervous System and the effector in the | autonomic nervous system |
neurotransmitter in parasympathetic nervous system | acetylcholine |
preganglionic neurotransmitter sympathetic ns | acetylcholine |
postganglionic neurotransmitter sympathetic ns | norepinephrine |
neuron length sympathetic ns | short, long |
neuron length parasympathetic ns | long, short |
the adrenal medulla is part of | the sympathetic nervous system |
Preganglionic neurons synapse in the adrenal medulla releasing ________, which initiates the release of _______ into the circulation. | acetylcholine, epinephrine |
sarcoplasmic reticulum skeletal vs visceral | developed, not developed |
latent period of skeletal vs visceral | short vs long |
duration of contraction- skeletal vs visceral | milliseconds, seconds |
primary source of calcium for visceral smooth muscle | extracellular |
primary source of calcium for skeletal muscle | sarcoplasmic reticulum |
Visceral smooth muscle cells can be stimulated to contract through (2) | pacemaker cells, cell-to-cell activation |
Inherent rhythmicity is a property of | visceral (single unit) NOT multi unit |
slow wave potentials | Rhythmic sub-threshold oscillations in membrane potential |
slow wave potentials are the result of | Na+/K+ pump |
when the membrane potential reaches threshold in the visceral smooth muscle pacemaker cell... | Ca++ gated channels open |
enteric nervous system | coordinate inherent contractions into peristalsis and segmentation |
effect of atropine on an isolated segment of rabbit ileum | no effect |
effect of a cholinergic antagonist on an isolated segment of rabbit ileum | no effect |
cholinergic | parasympathetic |
adrenergic | sympathetic |
relative actin:myosin ratio in smooth muscle | more actin |