anatomy midterm Flashcards
terminal boutons
affect another neuron or effector organ
integration
interpretation of sensory input
ganglia
cell bodies outside the cns
where is root ganglion
only on dorsal
dorsal =
ventral =
sensory
motor
white matter =
gray matter =
axons, myelin (fat)
the cells
spinal reflex
initiates a response without input from the brain
posterior horn
sensory processing
anterior horn
motor signals to skeletal muscles
lateral horn
only in thoracic and lumbar regions
central component in sympathetic ans
reflex action
involuntary motor response to sensory stimulus based on reflex arc
reflex arc
afferent - receptor and neuron
efferent - nerve and effector organ
lateral horn
T1-L2
general somatic senses
touch
pain
vibration
pressure
temperature
proprioceptive
stretch in tendons and muscles
body sense
special somatic senses
hearing
balance
vision
smell
visceral sensory
general - stretch, pain, temp, nausea, hunger
widely felt in digestive, urinary, and reproductive organs
general somatic motor
voluntary control
contraction of skeletal muscles
visceral motor
regulates smooth and cardiac muscle
ANS
involuntary nervous system
autonomic nervous system
sympathetic - mobilize body for stress
parasympathetic - recover body form stress
antagonistic, dual innervation
somatic division
cell bodies reside in CNS
axons extend all the way to skeletal muscles
chains of two motor neurons
preganglionic neuron - in brain or cord
postganglionic - outside CNS
alpha 1
vascular smooth muscles, skin, BP increase
constrict
alpha 2
GI tract BP increase
constrict
beta 1
SA node, AV node, ventricular myocardium, adipose tissue and kidney
dilate
beta 2
bronchioles, walls of GI tract, urinary bladder
dilate
where is parasym
thoracic and lumbar
where is sym
cranium and sacrum
leads to every part of body
norepinephrine
autonomic neuropathy
damage to nerves that manage everyday body functions
symptoms: loss of bladder control, dizzyness, diarrhea/constipation, difficulty eating/swallowing
can be caused by diabetes
horner syndrome
sympathetic postganglionic interruption lead to domination by PSNS
miosis: decreased pupil size
anhidrosis: decreased sweating
ptosis: drooping eyelid
one side of face
raynaud’s syndrone
sympathetic disorder
body feels numb and cold
excessive constriction
fingers, toes, ears, and tip of nose
changes in color of skin
parasympathetic nervous system dysfunction
issues with digesting food
bladder dysfunction
abnormal sweating
postprandial hypotension
sudden drop in BP after meal caused by BP changes during digestion
orthostatic hypotension
sudden drop in BP when a person stands up
decrease in blood to brain
feels dizzy
autonomic dysreflexia
catheter blockage
stretched bladder sends message to spinal cord
when reach T6 sym activated and release norepi
blood vessels in skin and abdomen constrict
rise in BP sends signal to brain
sends parasym message from vagus to heart to slow
signal does not pass T6 and BP continues to rise
where does the lower motor neuron start?
anterior horn of spinal cord
how many motor neurons does each muscle have?
depends on muscle size
what does NMJ release?
Acetylcholine
fasciculus
small bundle of muscle fibers
myofibril
composed of actin and myosin
epimysium
covers whole muscle
helps prevent spread of signal for muscle activation
perimysium
covers bundles of fibers (fasciculi)
endomysium
covers individual muscle fibers
z lines
at end of each sarcomere
h zone
middle of each sarcomere
only myosin
disappears when muscle contracts
i bands
edges of sarcomere
only actin
a band
overlapping actin and myosin
m line
middle of h zone
hods myosin in place
myosin filament components
heads: made of myosin ATPase
tails: intertwine to form myosin filament
crossbridge: pulls actin over myosin
sliding filament theory
electrical impulse generates to NMJ
impulse spreads across sarcolemma into T tubules
receptors release ca2+ into muscle fiber
Ca2+ binds to troponin
tropomyosin uncovers active site on actin
myosin crossbridge heads bind actin, form actomyosin complex
heads pull actin to center of sarcomere (power stroke)
force is produced
how does eccentric contraction happen?
external load forces eccentric contraction
how do muscles loose tension?
when they are over or understretched they have less tension
type I muscle fibers
slow twitch
low peak force
fatigue resistant
constant oxygen supply
aerobic
long term activity
type II muscle fibers
fast twitch
rapid and high peak force
low capacity for oxidative metabolism/anaerobic
fatigue easily
effects of endurance training
increase in capillary density
increase size and number of mitochondria
increase in ability to produce ATP
hypertrophy
increase size of muscle fibers
requires addition of myonuclei to support increase
when you have multiple different measurements, which do you take?
the lowest
in what order does blood leave and return to heart?
left vent
arteries
veins
right atrium
pericardium
outermost layer
myocardium
facilitates pumping action
contractile elements
myocardial cells
automaticity
rhythmicity
conductivity
endocardium
innermost layer
mediastinum
between right and left pleura of lungs
how do the lungs get nutrients
blood flow from bronchiole arteries
not from right vent - only for oxygenation
which ventricle is larger and why
left is bigger and stronger
pumps to body
oxygenated blood is heavier
intercalated disks
fibers are connected so they all contract together
only located in ventricles
heart attack is the death of cells
what vein does the anterior descending (inter-ventricular) artery run with
great cardiac vein
where does the coronary sinus empty into
right atrium
right coronary artery branches and where they supply
sinus node artery - right atrium
right marginal artery - right ventricle
posterior descending artery - inferior walls of both ventricles and inferior interventricular septum
left coronary artery branches and where they supply
circumflex artery - left atrium and left ventricle
left anterior descending artery - anterior portion of interventricular septum
where are blood vessels in the heart located and why? what layer?
located in the epicardium - most superficial layer
so that they are not constricted when the heart contracts
flow of blood through the heart
enters R atrium from sup and inf vena cava
passes though AV valve into R ventricle
through valve into pulmonary trunk
through pulm arteries to lungs
oxygenated and returned to LA via pulm veins
through AV valve into LV
through valve into aorta and through body
where is blood supply the highest
in aorta
also very high in arteries supplying the heart
anastomosis
intercommunication between 2 arteries ensuring blood flow to area even if one artery is blocked
what part of the heart makes the sound
in a healthy heart, the valves make the sounds
sound 1
lub
mitral and tricuspid valves closing at onset of systole
what is systole?
contraction of ventricles
sound 2
dub
aortic and pulmonic valves closing at onset of diastole
what is diastole
filling of ventricles
sound 3
ventricular gallop
volume related
associated with cordae tendineae, heart failure
does not eject enough blood
the sound of more blood entering the ventricle
sound 4
atrial gallop
pressure related
vibration of vent wall due to hypertension and MI
why would S4 exist
the walls are thicker and need more pressure to expand and make space because they are stiffer than normal
where to listen
APT M 2245
aortic valve - 2nd-3rd right interspace
pulmonic valve - 2nd-3rd left interspace
tricuspid valve - left sternal border
mitral valve - apex
order of abnormal sounds
S3 before S4
S4 before S1
cardiac cycle in relation to ventricles
systole - contraction, blood pumped out
diastole - relaxation, blood fills chamber
autorhythmaticity
ability to initiate impulse for contraction at regular intervals - continuously works
sinoatrial node (SA)
intrinsic
pacemaker of contraction
located in superior right atrium
atrioventricular node (AV)
intrinsic
delays impulse by 1/10 of a second, allowing atria to contract before ventricles
located in inferior medial right atrium
purkinje fibers
intrinsic
rapidly spreads impulse to contract throughout ventricles
only located in ventricles
parasympathetic nerve fibers
(function in heart)
extrinsic
decrease heart rate via vagus nerve
sympathetic nerve fibers
(function in heart)
increase heart rate
bradycardia
slow heart rate
often training induced
tachycardia
increased heart rate
cardiac muscle
capable of contraction and force generation
capable of initiating impulse
has intercalated discs that spread impulse to contract
syncytial contraction
fibers contract simultaneously
fibers hace high mitochondrial density
fibers have extensive capillary network
fibers use aerobic energy for contraction
cardiac wall thickness
the thicker to wall, greater the force
~ left ventricle has greater thickness, supplies whole
body
regular physical training and chronic hypertension results in thickening of left vent wall and increase in left vent mass
duration of each segment of ECG
p wave - .8 sec
PR segment - .8
QRS interval - .8
ST segment - .12
T wave - .16
atrial depolarization
p wave
ventricular depolarization and atrial repolarization
QRS interval
ventricular repolarization
st segment and t wave
cardiac cycle duration equation
60 seconds/ HR
when to chambers contract?
repol or depol
when depolarization is complete
cardiac cycle according to atria
atrial diastole - second half of QRS through first half of p wave
atrial systole - second half of p wave through first half of QRS
cardiac cycle according to the ventricles
ventricular diastole - after t wave through first half of QRS
ventricular systole - second half of QRS through t wave
which part of myocardium repolarizes later
inner myocardium repolarizes later than outer myocardium
cardiac output
amount of blood pumped per minute
Q = HR x SV
5 L/min for men and 4.5 L/min for women
resting Q will be the same in trained and untrained
assume resting unless specified
Q increases as you start doing exercise
stroke volume
amount of blood pumped per contraction of ventricle
trained have higher SV
SV = EDV - ESV
end diastolic volume
blood in ventricles at end of diastole
end systolic volume
blood in ventricles at end of systole
ejection fraction
ratio of available blood pumped to pumped blood
EF = SV/EDV
.4 has pathology
.7 is normal
.8 is trained
