Human Physiology Final exam

Monosynaptic reflex

has a single synapses between the afferent and efferent neurons

Polysynaptic reflexes

have two or more synapses. This somatic motor reflex has both synapses in the CNS

Proprioceptors

are located in skeletal muscle. joint capsules and ligaments

Somatic motor neurons carry ______ signal.

output

Effectors

are contractile skeletal muscle fibers, or extrafusal muscle fibers

CNS integrates _____ signal.

input

The three types of proprioceptors are

Joint receptors, golgi tendon organ, and muscle spindle

Golgi tendon organ and muscle spindle are found in _____

Skeletal muscle

Joint receptors are found in ______

Capsules and ligaments around joints

______ senses the changes of joints.

Joint recpetors

With joint receptors the sensory information is integrated in _______

the cerebellum

Golgi tendons organs respond to

Muscle tension

Golgi tendon organ is surrounded by ______ fibers and in between the extrafusal muscle fibers and the tendon.

collagen

Myotatic unit

the collection of the pathways controlling a single joint

Reciprocal inhibition

antagonist muscles must relax as the prime mover muscles contract

Reflex

integrated at the spinal cord or brain stem

Rhythmic

integrated in the spinal cord with higher center input required

Voluntary

integrated in cerebral cortex

The two sets of heart valves ensure one-way flow

Atrioventricular valves and semilunar valves

During ventricular contraction, the _______ remain closed to prevent blood flow backward into the atria

AV valves

The _____________ prevent blood that has entered the arteries from flowing back into the ventricles during ventricular relaxation

semilunar valves

Contractile cells

Striated fibers organized into sarcomeres

Autorhythmic cells

Pacemakers, set heartbeat rate and DO NOT have organized sarcomeres

Desmosomes

allow force to be transfered

Gap junctions

provide electrical connection

______ starts with the heart pacemaker cells

Action potential

Action potentials

• Voltage-gated L-type ____ channels in the cell membrane open (extracellular calcium contributes 10%)

• _______ receptors open in the sarcoplasmic reticulum (SR)

• _______ binds to troponin

• _________ cycle as in skeletal muscle

• Ca2+

• Ryanodine

• Calcium

• Crossbridge

During relaxation, _____ is removed from cytoplasm: back into the SR with Ca2+ ______ and out of the cell through the Na+-Ca2+ exchanger

• calcium

• ATPase

Force generated is proportional to _____________, which is determined by how much ______ is bound to troponin.

number of active crossbridges, calcium

Sarcomere length affects ________

force of contraction

Myocardial contractile cells

– Depolarization due to ______.

– Repolarization due to ______.

– Long action potential (plateau) due to ______

Na+ entry, K+ exit, and Ca2+ entry

Myocardial autorhythmic cells

– Unstable membrane potential called _______

– Depolarization is due to _______

pacemaker potential, Ca2+ channels opening

Sinoatrial node (SA)

Sets the pace of the heartbeat at 70 bpm

AV node (50 bpm) and Purkinje fibers (25–40 bpm) can act as _______under some conditions

pacemakers

Internodal pathway from SA to atrioventricular (AV) node

– Routes the direction of electrical signals so the heart contracts from______.

– AV node delay allows the atria to complete their contraction before _______ contraction begins

• apex to base

• ventricular

__________ transmit electric signals down the atrioventricular bundle (bundle of His) to left and right bundle branches.

Purkinje fibers

______: atrial depolarization

_______: conduction through AV node and AV bundle

_________: ventricular depolarization

______: ventricular repolarization

• P wave

• P-R segment

• QRS complex

• T wave

EKG analysis

______: time between two P waves or two Q waves

Heart rate

EKG analysis

_____: regular or irregular ?

Rhythm

EKG analysis

______ analysis: presence and shape

Waves

Cardiac cycle:

a single contraction-relaxation cycle.

Diastole:

cardiac muscle relaxes

Systole:

cardiac muscle contracts

The _______: atrial and ventricular late diastole

– The atria are filling with blood from the veins.

– AV valves open → _________

heart at rest, ventricles fill

_______: completion of ventricular filling

Atrial systole

Ventricular contraction

– Isometric ventricular contraction: both __________ valve are closed.

– Ventricular ejection: ventricles finish contracting, pushing semilunar valves open and blood is ejected into ______.

AV valve and semilunar, arteries

Ventricular diastole

– Ventricular relaxation and pressure _____, arterial blood flows back pushing semilunar valves shut.

– Isovolumic ventricular relaxation: volume of blood in ventricles ______.

– AV valves open when ventricular pressure drops ________.

drops, not changing, below atrial pressure

Note the steps and cylces

1

Atrial contraction starts at the end of _____

P wave

_________ signal goes through AV node and AV bundle

P-R segment

___________ starts at the end of Q wave and continues through T wave

Ventricular contraction

First heart sound

– Vibrations following the closure of the ______

– “Lub”

AV valves

Second heart sound

– Vibrations created by closing of _______

– “Dup”

semilunar valve

Auscultation

is listening to the heart through the chest wall through a stethoscope

End diastolic volume (EDV)

– The ventricle volume at the end of ____

diastole

End systolic volume (ESV)

– The ventricle volume at the end of

systole

Stroke volume

– Amount of blood pumped by one _____ during a contraction

– Volume of blood ____ contraction-volume of blood _____ contraction = stroke volume

– EDV – ESV = _____ volume

– Average = ___ mL

• ventricle

• before, after

• stroke

• 70

Cardiac output (CO)

– Volume of blood pumped by one _____ in a given period of time

– Cardiac output = heart rate * stroke volume

– Average = __ L/min

• CO is a measurement of ________.

• ventricle

• 5

• cardiac performance

The parasympathetic neurotransmitter __________ slows heart rate

acetylcholine (ACh)

The sympathetic neurotransmitter ____________________ increases heart rate

norepinephrine and epinephrine

Tonic control of heart rate is dominated by the _______ branch.

parasympathetic

Epinephrine, norepinephrine, and digitalis have _____ inotropic effects

positive

Chemicals with _____ inotropic effects decrease contractility

negative

Afterload

is the resistance against which the heart must work to eject blood during systole

Ejection fraction (EF) is the percentage of EDV ejected with one contraction,

i.e., (Stroke volume/EDV)x 100%