Nerves n Heart Flashcards
these inform the brain as to the amount of tension in the muscle and tendons
Golgi tendon
these inform the nervous system of the length of the muscle
muscle spindles
what r the two motor divisions of the PNS?
describe
somatic (voluntary)
autonomic (involuntary)
what are the two subdivisions of the ANS?
what do they do?
sympathetic (speeds up)
parasympathetic (slows down)
what part of a nerve cell is considered a network of neurofibrils?
cell body
come shaped are of a nerve cell from which the axon arises
axon hillock
what are clusters of cell bodies called in the CNS?
PNS?
CNS - nuclei
PNS - ganglia
this part of a nerve cell is the short, tapering, and diffusely branched, receptive region
dendrite
what conveys impulses toward the cell body?
dendritea
what is the region of neuronal secretion?
where are they located
synaptic knobs
end of axon
what is the conducting region of a neuron?
axon
what are sheaths created by?
Schwann cella
what do impulses jump over on the axon?
what is this process called
nodes of ranvier
saltatory conduction
what is the speed of saltatory conduction?
reg conduction?
5-30m/sec (~10-60mph)
.5-2m/sec (~1-4mph)
what are the 5 parts of the reflex arch in order?
- receptor
- sensory neuron
- integration center
- motor neuron
- effector
what do nerves primarily run on?
glucose
this is compose of 3-10 short intrafusal muscle fibers in a connective tissue capsule
muscle spindle
what are intrafusal fibers wrapped with
type 1 and type 2 sensory nerve fiber
the purpose of this is to relay muscle tension info.
what does this process cause and why?
Golgi tendon reflex muscle relaxation (lengthening) in response to tension helps prevent damage do to excessive stretch
what activates the Golgi tendon organ?
contraction or passive stretch
which part of the brain coordinates fine motor movement, precision, timing, accuracy, and posture?
what is another name for this part?
cerebellum (the little brain)
also called the sensory lobe.. major center for sensory info other than smell, hearing and vision
parietal
Executive function part of the brain.. used for voluntary motor skills, movement, aggression, sense of smell
frontal
hearing part of the brain.. important in hearing and smell as well as in abstract thought processes
temporal
vision part of the brain. reception and integration of visual stimulus and is distinct from the other lobes
occipital
what is increased in the brain which aids in neurogenesis through exercise and PA
which parts of the brain?
brain derived neurotropic factor (BDNF)
prefrontal cortex and temporal lobes
3 primary functions of the heart
O2 to cells
CO2 and waste away from cells
regulate body temp
where is the heart located?
in the mediastinum bw 2nd rib and 5th intercostal space
what r the two purposes of the pericardium?
protect, anchor and prevent overfilling
fluid filled pericardial cavity decreases friction
visceral layer of the serous pericardium
epicardium
spiral bundles of cardiac muscle cells w crisscrossing layers of connective tissue
myocardium
continuous w endothelial lining of blood vessels
endocardium
what internally separates the atria
interatrial septum
what are the two ventricles separated by
interventricular septum
which side of the heart carry blood to and from the lungs
right
which side of the heart carry blood to and from all body tissues?
left
what are the walls of the atria ridged by?
pectinate muscles
what are the ventricles ridged by?
trabeculae carneae
what is the main purpose of AV valves?
prevent back flow into the atria when ventricles contract
what is the “lub” sound?
what does this sound signify?
Av valves closing
signifies beginning of systole
what is the “dub” sound?
what does this sound signify?
semilunar valves closing
signifies beginning of ventricular diastole
these cells are striated, branched, and connected at intercalated disks
cardiac muscle cells
at the intercalated disks, what are the cells held together by?
desmosomes
what does the electrical impulse to contract move through?
gal junctions
what r two differences in cardiac contraction compared to skeletal muscle contraction
- depolarization wave opens slow Ca+2 channels in the SR
2. Ca+2 surge prolongs the depolarization phase n continues the contraction
describe the intrinsic conduction system of the heart
SA node - AV node- AV bundle - bundle branches - purkinjie fibers
pacemaker of the heart
SA node (sinoatrial)
how fast does the SA node generate an impulse
100 times/minute
how fast does the AV node generat an impulse in absence of the SA mode?
50 times/minute
the only electrical connection bw the atria and ventricles
AV bundle (bundle of His)
two pathways in the interventricular septum that carry impulses toward the apex of the heart
right n left bundle branches
what do the purkinjie fibers do?
cause the apex, papillary muscles. an the ventricular walls to depolarize
how fast do the AV bundle and purkinjie fibers depolarize in absence of AV node input?
30 times/minute
what modifies heartbeat?
the ANS
where are cardiac centers located?
brain stem (medulla oblongata)
what cardiac center innervates through sympathetic neurons?
what parts of the heart does it affect?
cardioacceleratory center
innervates the SA n AV node, heart muscles, and coronary arteries
what center inhibits through parasympathetic fibers?
what parts o the heart does it affect?
in what nerves?
cardioinhibitory
SA and AV node
in vagus nerves
when the heart is contracting
systole
when the heart is relaxing
diastole
volume of blood in the left ventricle at the end of ventricular diastole
end diastolic volume (EDV)
volume of blood remaining in the left ventricle after systole
end systolic volume (ESV)
volume of blood ejected from the left ventricle
stroke volume (SV)
what is the equation for stroke volume?
EDV - ESV
volume of blood pumped each min
?/?
cardiac output (Q) (ml/min)
what is the cardiac output approx at rest
~5 liters/min
what is the typical cardiac output during exercise?
~20 - 40 liters/min
stretch of the heart immediately before contraction?
what law?
preload
frank-starling law
force of contraction
contractility
back pressure of blood on the semilunar valves
afterload
muscles contract causing blood to b pushed toward the heart
why does this work
muscle pump
bc veins have valves
what three factors affect preload?
muscle pump
increased time bw systole and diastole
time of exercise
what two factors affect SV
contractility
afterload
t/f
resting heart rate is faster after meals
t
abnormally fast heart rate?
how fast is abnormal?
tachycardia
>100 bpm
what does tachycardia lead to if persistent?
fibrillation
abnormally slow heart rate?
what is the bpm for this?
bradycardia
<60 bpm
what is normal bpm?
bw 100-60 bpm
what are four age-related changes that affect the heart?
sclerosis and thickening of valve flaps
decline in cardiac strength
fibrosis of cardiac muscle
atherosclerosis
how long does CV training take to lower HR?
approx 12 weeks
t/f
CV training lowers HR at submaximal and max exercise
f
HR is unchanged at max exercise
t/f
CV training increases SV at rest, submaximal, and max exercise
t
how long until plasma volume is higher?
6 wks
is childrens’ SV bigger or smaller than adults’
smaller
what age range does ma HR not change for kids
7-15
what is the average max HR for kids
185-215
t/f
kids have less sweat glands than adults
f
