Exam 2 Study Questions Flashcards
Contains cranial nerves, spinal cord, and cardiac units.
cranial nerve 1
olfactory
cranial nerve 2
optic
cranial nerve 3
oculomotor: eye muscles, ciliary muscles, iris muscles
cranial nerve 4
trochlear: superior oblique, extrinsic eye muscle
cranial nerve 5
trigeminal: sensory, face and head
cranial nerve 6
abducens: lateral rectus, extrinsic eye muscle
cranial nerve 7
facial: motor muscles of the face, salivary glands, tear glands, sensory like taste buds on anterior of the tongue
cranial nerve 8
vestibulocochlear: cochlea vestibule and semicircular canals of the inner ear
cranial nerve 9
glossopharyngeal: motor muscles of the pharynx, taste buds on the posterior of tongue
cranial nerve 10
vagas: muscles of pharynx, larynx, thoracic, and abdominal organs, sensory taste buds on tongue and pharynx, thoracic and abdominal organs
cranial nerve 11
accessory: muscles of the larynx, pharynx, soft palate, shoulder and neck
cranial nerve 11:
hypoglossal: tongue muscles
white matter
transmission of information from brain to body
grey matter
integrating reflex activity between afferent input and efferent output
polysynaptic
more than two neurons connected
monosynaptic
only two neurons, cannot be infringed on by the brain
What are the components of the reflex arc?
sensory receptor -(sensory neuron)-> spinal cord –> interneuron -(motor neuron)-> spinal cord –> skeletal muscle cell
How are muscles the contractile specialists of the body?
It allows for so many bodily functions including allowing bones to move, swallowing food, breathing, cardiac movements, movement of blood, shivering/heat production, etc.
whole muscle is called
organ
a muscle cell is called
a fiber
intracellular structures of muscle cells are called
myofibrils
cytoskeletal elements of muscle cells are called
thick and thin filaments
thin filament
actin
thick filament
myosin
smallest functional unit of muscle cells
sarcomere
Z line
the rungs of the actin latter
M line
holds myosin in place
H band
distance between two actin filaments across a sarcomere
I band
light band, isotropic, actin
A band
dark band, anisotropic, myosin
2:1
actin:myosin
during a contraction..
_____ remain unchanged
_____ shorten
A band and M line remain unchanged
Z lines, H band, and the whole sarcomere shorten
sliding filament theory
thick and thin filaments for a cross-bridge, and together with ATP, create a power stroke to move Z bands together
excitation contraction coupling
the series of events that link the action potential (excitation) of the muscle cell membrane to muscular contraction
actin structure
double stranded, globular protein
also contains tropomyosin and troponin
tropomyosin
regulatory protein that prevents myosin from binding to actin
troponin
regulatory, Ca2+ dependent protein attached to tropomyosin on an actin filament
in the presence of Ca2+, moves tropomyosin out of the way to allow for myosin to bind
myosin structure
six polypeptide subunits
90deg at rest, 45deg when ‘loaded’
hinge region for movement
insoluble tail region
head region containing an actin binding domain and a myosin ATPase binding domain
How is the role of Ca2+ different in skeletal, cardiac, and smooth muscle?
Describe the steps of the cross-bridge cycle in skeletal muscle.
- energized - no Ca2+, no cross-bridge, 90 deg angle
- binding - Ca2+ is present, cross-bridge can form, tropomyosin slides out of regulatory position
- power stroke - lowest free energy is 45deg, myosin bends taking actin with it, ADP and Pi fall off, if no more ATP = rigor
- detachment - ATP binding to myosin breaks the bridge, lowest free energy is 90deg,
components of a twitch
latency, contraction, relaxation
latency
period of excitation-contraction coupling
contraction
period during which cross-bridge formation and filaments sliding
relaxation
SR (sarcoplasmic reticulum) and lateral sacs take up Ca2+, myosin returns to 90deg rest
one action potential =
one twitch
twitch explaination
not useful for work
response to single AP
subthreshold muscle response
tetany
smooth, sustained contraction
3-4x stronger than a twitch
increased frequency of cross-bridge cycles
steady [Ca2+] assists in smooth movement
summation
from multiple AP
similar to temporal summation of EPSP
increasing tension
three types of fatigue
cellular
neuromuscular
central/psychological
recovery
increased blood flow to increase O2 uptake
match O2 dept to ATP consumption
O2 debt equation
(energy consumed during activity) - (energy supplied by body)
small motor unit
refined, precision movements
1-12 fibers
large motor unit
coarse, powerful movements
increased tension
>2,000 fibers
muscle atrophy - exercise
increase glycogen stores
increases number of mitochondria
increases number of capillaries
hypertrophy of muscles
hypertrophy
building sarcomeres in parallel
muscle atrophy - immobility
terminal sarcomeres can die
hyperplasia
scar formation with death of sarcomeres
hyperplasia
development of new sarcomeres from stem cells (limited)
muscle atrophy - denervation
frequency of AP during development will drive formation of muscle type
electrical stimulation may slow atrophy
muscle atrophy - aging
30% of myofibrils become fat by age 80
automatic decrease in motor unit size, less tension
Ach synthesis
smooth muscle characteristics
single nucleus
spindle arrangement does not extend the length of muscle fibers, sheets
thin filaments are not actin, no troponin
third contractile protein = intermediate filaments
lacks myofibrils
not striated
no Z lines, bu modified dense bodies made of actinin
lacks T tubules
collagen fibers
rigid, limit organ volume
elastin fibers
allows distension of organs/blood
law of La Place
sigma (stress) = [P (wall pressure)* r (vessel radius)]/ w (width of smooth muscle)
if width goes up…
stress goes down
if radius gets smaller…
the stress also goes down
two pools of Ca2+
- sarcoplasmic reticulum (SR) - small
- voltage gated channels on the sarcolemma - large
the Ca2+ gates can be opened by
- voltage
- neurotransmitter
- hormones
IP3
a second messenger of smooth muscle
calmodulin
structurally similar to troponin, Ca2+ binds to form a complex
inactive myosin protein complex is converted to its active form
calmodulin phosphorylates…
myosin at a serine residue in the tail portion
only in the myosin of the smooth muscle
in smooth muscle tropomyosin acts as…
a structural protein
only in a ___________ state can smooth muscle achieve a cross-bridge
phosphorylated
four locations/actions that require ATP
- pump Ca2+ back into the SR
- pump Ca2+ out of the cell into the ECF
- phosphorylate myosin tail
- bind to head of myosin during step 4
smooth muscle is __________, slow when completing the cross bridge cycle
economically favorable
latch phenomena
actin/myosin covalent linkage
skeletal muscle cycle
2 ATP
100 ms
smooth muscle cycle
4 ATP
3 sec
self-generated electrical signals in two categories
multiunit and signal unit
multiunit
multiple discrete units
each fiber contracts independently
not very much of it
neurogenic
involuntary
usually in large blood vessels
single unit
excited and contact as a unit
single sheet
myogenic
found in hollow organs
two types of single unit smooth muscle
- pacemaker activity
- slow wave potential
pacemaker activity
membrane potential gradually reaches threshold
w/o nervous system
can be modulated
slow wave activity
oscillating + drifting membrane potential
self induced
produces a train of AP
basal electrical rhythm
three roles of a multicellular organism
- deliver glucose
- deliver O2
- remove waste
three primary roles of human circulatory system
- transportation
- regulation
- protection
tricuspid
right atria/right ventricle valve
open when ventricle is contracting
pulmonary semilunar
right ventricle/pulmonary artery
open when ventricle is contracting
mitral
left atrium/left ventricle
open when ventricle is relaxing
aortic semilunar
left ventricle/aortic arch
open when ventricle is contracting
stroke volume
volume of blood dispelled from the heart every beat
cardiac output equation
cardiac output = (stroke volume)(cardiac rate)
valves provide two main things
- one way blood flow
- regulated/control blood flow
fetal circulation is achieved via…
- Faraman ovale
- ductus arteriosis
faraman ovale
between two atrium, also observed between two ventricles
ductus arteriosis
connection between the pulmonary artery and the aortic arch
cyanosis
septum defect between chambers
_____ to _____ shunt
right, left
neurogenic
driven by nerves in the ANS
myogenic
produced from the muscle itself, self excitable
two types of nerves innervate the heart
parasympathetic, sympathetic
parasympathetic nerve
vegas, conserves the energy of the body system, lowers bpm
sympathetic nerve
sympathetic ganglion, prepares body for an emergency , fight/flight response, accelerates bpm
systole
orderly contraction of the heart
diastole
relaxation phase of the cycle
important implications of AP in the heart
maintenance of AP plateau is driven by Ca2+
absolute refractory period is extended
different channels that underlay the different AP in the myocardium in order to regulate
two principles of action potentials
fast and slow response
fast response
atria, ventricles, purkinje fibers
steep upsweep and large amplitude
L type Ca2+ channel, long lasting
cannot spontaneously depolarize
slow response
SA and AV nodes
T type Ca2+ channel, transient but responsible for the upsweep
resting membrane potential is not stable
spontaneous depolarization
activated first !
1-2 in heart beat graph
atria contracting
2-3 heart beat graph
atria relaxes
3-4 heart beat graph
ventricle is contracting
4-5 heart beat graph
pressure is falling, ventricles relaxing
S1
in line with 3, closure of tricuspid and mirtal
S2
in line with 5, closure of pulmonary semilunar and aortic semilunar
S3
ventricle vibrating in a child, heart disease in adults
S4
normal, atria contract
P wave
atria depolarization
Q, R, S
two events
- ventricle depolarization
- repolarization of atria
T wave
repolarization of ventricles
what is a heart murmur?
blood regurgitates back through valves
bradycardia
less than 60 bpm
normal heart beat
75 bpm
tachycardia
greater than 100 bpm
ectopic pacemakers
cells outside of the SA node assume pacemaker activity
ventricular tachycardia
ectopic pacemaker activity explicitly in the ventricles causing them to beat separately from the atria
flutter
200-300 bpm, regular rhythm but usually leads to fibrillation
atrial fibrillation
the pumping action of atria steps; ventricles still pump 80% of the blood, can live for years w/o knowing
ventricular fibrillation
the pumping action of ventricles stops; only 20% of blood, only lives minutes
how to fix atrial fibrillation
reestablish proper atria rhythm via drug therapy, increases refractory period
how to fix ventricular fibrillation
reestablished via large shock to the heart causing complete refraction and hope the heart restarts
normal P, Q, R, S time
0.12 to 0.2 seconds
atrioventricular (AV) block
diagnosed by changes in the PQRS period
1st degree AV block
> 0.2 seconds, too long
2nd degree AV block
AV node damaged, and only 2/3 of the AP make it to the ventricle
multiple P waves w/o and associated QRS
3rd degree AV block
no AP reach the ventricles, atria beat via SA node and ventricles beat via ectopic pacemakers; ventricle beat os irregular
myocardial infarction (MI)
heart attack, suppressed or irregular QRS, accompanied by reduced O2
ischemia
low O2 environment, ST depression
away from the heart
arteries, arterioles
true gas exchange occurs in
capillaries
back to the heart
veins, venuoles
“metarteriole”
only in some vessels, provides pressure balance following the path of least resistance from artery to vein
artery characteristics
very muscular, thick
have stretch receptors
100-110 mmHg pressure
three tunics of arteries
- tunica externa (adventida)
- tunica media
- tunica interna
capillary characteristics
ring muscles control precapillary sphincters
- hormonally and neurally controlled
relax = open bed (exercise)
close = contraction (thermoregulate)
gas exchange
vein characteristics
not as muscular
30 mmHg pressure
assisted blood flow by skeletal muscle
has backwash valve
LDL
low density lipoprotein, carries cholesterol to all cells
HDL
high density lipoprotein, carries cholesterol to liver, bile, or degrade it
thrombosis
accumulation of a lipid plaque
embolism
moving thrombosis
treatments for thrombosis
replace vessel with a bypass
angioplasty
blood thinners
stints
intravessel cementation