Physiology Exam 3 Material

Chapters 13 & 14

All neural reflexes begin with

a stimulus that activates a sensory receptor

somatic reflexes have __ neuron(s)

one

autonomic refelxes have __ neuron(s)

multiple

which type of relfex is always polysynaptic?

autonomic

Limbic system is aka.

visceral brain

Limbic system processes

primitive drives (sex, fear, rage, aggression, and hunger)

tonic control

constant stimulus

skeletal muscle does not have __ neurons to relax

inhibitory

how does relaxation in skeletal muscle occur?

inhibitory interneurons in CNS blocks activity od somatic motor neurons

stretch reflex

contraction response triggered by muscle spindle to muscle stretch and preventing overstretching

muscle spindle

specialized sensory receptors within muscles to detect change in length and strength

example of simplest monosynaptic stretch reflex

patellar tendon reflex

reciprocal inhabition

antagonistic flexor muscles relax to extend leg

Flexion reflexes

polysynaptic reflex pathway that pull limbs away from painful stimuli

capillaries

microscopic vessels where blood exchange material

primary function of cardiovascular system

transport material throughout the body

Blood flows from __ to ___

higher presses to lower pressure

systole

when heart contracts / squeeze

systole has __ pressure

high

diastole

when heart relaxes / fills with blood

pressure gradient

difference in pressure between two ends of a tube filled with fluid

pressure flow is

high → low

3 components resistance is influenced by

1. radius of tube

2. length of tube

3. viscosity of fluid

vasoconstriction

decrease in blood vessel diameter (decreasing flow)

vasodilation

increase in blood vessel diameter (increasing flow)

primary determinant of velocity is the total area of

all capillaries

myocardium

muscular layer of the heart responsible for pumping

chordae tendineae

prevents atrioventricular vales from flipping backwards during contraction

when comparing action potentials of myocardial contractile cells, they do not experience __

hyperpolarization

conducting system of the heart

(electrical signaling begins in SA node)

1. SA node depolarizes

2. electrical activity to atrioventricular node

3. atrioventricular bundle

4. right and left bundle branches

5. purkinje fibers