16. Cardiovascular 4 Flashcards
What are the 4 results of HF (heart failure)?
- apoptosis of heart cells
- necrosis of heart cells
- fibrosis
- hypertrophy
Describe hypertrophy of the heart during HF
its when the heart muscle is overworked causing the muscle to grow. This growth leaves less space for blood flow
What are the 2 main things that could occur wrt the remodeling from chronic HF?
- muscle growth = less space for blood flow
- receptor desensitization = reduced response to contractility
Describe the treatment for HF. Is this a permanent solution?
beta-receptor blockers = slow down the progressive symptoms by DEC the HR. This is not a cure.
a) What are myocardial cells?
b) What do myocardial cells contain?
c) What is a sarcomere?
a) heart muscle cells used to cause the contractions
b) actin filaments and myosin filaments
c) the scaffolded form that the filaments are arranged in
How do the 2 filaments in the sarcomere interact to contract the heart
they slide along each other
Describe striations
scaffolding = thin-thick-thin-thick
Describe how the myocytes and myocardial cells communicate in order to allow for contractions in the heart
they connect via gap jxns at the ends
What are intercalated discs
the border of the 2 myocytes where the gap jxns that connect them are concentrated
W/in the cardiac muscle, the fibers contain all of the following except
a) mitochondria
b) sarcoplasmic reticulum
c) Ca2+ storage
d) group of myocytes
e) all are contained in a fiber
c - Ca is w/in the SR not the fibers directly
describe the 6 steps involved in the excitation-contraction coupling in the cardiac muscle using the following terms; SA-node, AP, depolarize, voltage-gated Ca channel, Ca release channel, myocardial cell, cytoplasm, SR, contraction, relaxation, Ca-ATPase pump, sarcomere, Ca.
- the SA node triggers an AP causing a depolarization
- the voltage-gated Ca channels open allowing for an influx of
Ca into the cytoplasm of the myocardial cell - The Ca release channels open w/in the SR allowing for the efflux
of Ca from the interior of the SR to the cytoplasm of the myocardial cell - the Ca binds to the sarcomere stimulating a contraction
- Ca-ATPase pumps Ca back into the SR
- the myocardial cell relaxes
Fill in the image using the following
a) voltage-gated Ca channel
b) Ca release channel
c) troponin
d) sarcoplasmic reticulum
e) Ca-ATPase pump
f) transverse tubule
g) sarcomere
a) green
b) blue
c) brown
d) pink
e) orange
f) yellow
g) purple
Match the following
a) thin
b) thick
1. actin
2. myosin
a) 1
b) 2
Put the following in order from outer to inner
a) myofibrils
b) myocardial cell
c) sarcomere
d) myofilaments
b -> a -> d -> c
Fill in the image using the following terms
a) striations
b) sarcolemma
c) myofibrils
d) myofilaments
e) sarcoplasm
f) nucleus
a) purple
b) yellow
c) pink
d) blue
e) green
f) orange
fill in the image using the following
a) A band
b) H band
c) I band
d) Actin
e) myosin
f) sarcomere
g) Z disc
a) purple
b) yellow
c) pink
d) blue
e) green
f) brown
g) orange
Describe the following
a) Z disc
b) sarcomere
c) I band
d) A-band
e) H-band
a) proteins that act as anchors for the actin filaments
b) the space in between two Z-discs
c) the section of the sarcomere that only contains actin filaments
d) the section of the sarcomere in which the actin and the myosin overlap
e) the center of the A-band that only contains myosin
This image is demonstrating what
a) relaxed myofibril
b) contracted myofibril
c) all of the above
d) none of the above
a
This image is demonstrating what
a) relaxed myofibril
b) contracted myofibril
c) all of the above
d) none of the above
b
a) What is the purpose of titin proteins?
b) What is the significance of them being elastic?
a) they are elastic proteins that anchor the myosin filaments to the z-disc in order to stabilize them.
b) it allows the muscle to return to its original length after being stretched
We know that during contractions sarcomeres shorten. How is it possible for the H-band to shorten if the A-band doesn’t?
the shortening is from the sliding of the filaments causing the H-band to shorten as more overlap of the filaments occurs leaving less space where only myosin filaments are present (H-band)
During the sliding filament theory, what happens to the following
a) A-bands
b) H-bands
c) I-bands
a) they move closer together
b) shortens -> disappears
c) shortens
What is the purpose of the angular heads at the end of the myosin proteins
they interact w/ the overlapping actin and pull it in order to induce a contraction (sliding filament)
Describe the following
a) tropomyosin
b) troponin
a) proteins attached to the actin and cover myosin binding sites while the sarcomere is relaxed
b) 3 subunit complex attached to the tropomyosin and acts as a Ca binding site that will remove tropomyosin when active
describe the steps involved in the sliding filament theory of contraction using the following terms; rest/relax, ADP, Pi, ATP, myosin, actin, head, SR, troponin, tropomyosin, Ca, power stroke, contract, slide
- resting myosin contains bound ADP and PI
- the Ca released by the SR binds to troponin
- conformational change in tropomyosin revealing the myosin binding site on the actin
- the myosin head interacts w/ the binding site on the actin causing it to release the Pi
- this induces a conformational change producing a power stroke allowing for the filaments to slide across each other
- ADP is released allowing for an ATP to bind to the myosin head causing it to detach from the actin
- the ATP hydrolysis to ADP and Pi returning to its relaxed form
fill in the image using the following
a) ADP + Pi
b) myosin
c) actin
d) cross bridge
e) troponin
f) tropomyosin
a) blue
b) yellow
c) orange
d) green
e) pink
f) purple
the cross-bridge cycle is also known as what?
the sliding filament theory of contraction cycle
_____ is ultimately responsible for controlling muscular contraction
a) ADP
b) Ca
c) Pi
d) ATP
e) all of the above
b
Describe the following for skeletal muscle contractions
a) generation of AP
b) anatomy/structure
c) mechanism of excitation-contraction coupling
a) needs external stimulation by the somatic motor nerves
b) the cells are long, non-branched with multiple nuclei and are structurally and fxnally separated
c) the Ca channels on the transverse tubules are interconnected to the Ca-releasing channels in the SR
Describe the following for cardiac muscle contractions
a) generation of AP
b) anatomy/structure
c) mechanism of excitation-contraction coupling
a) AP are produced automatically using HCN channels in the SA node
b) the cells are short, branched, and interconnected via gap jxns
c) the voltage-gated Ca channels in the transverse tubules are indep from the Ca-releasing channels in the SR
What type of muscle cell is this?
a) skeletal
b) cardiac
c) smooth
d) none of the above
a
What type of muscle cell is this?
a) skeletal
b) cardiac
c) smooth
d) none of the above
b
This image is showing the mechanism of the excitation-contraction couple for which type of muscle cell
a) skeletal
b) cardiac
c) smooth
d) none of the above
a
This image is showing the mechanism of the excitation-contraction couple for which type of muscle cell
a) skeletal
b) cardiac
c) smooth
d) none of the above
b
T or F - there is no known cure for HF
T
___ of patients w/ HF die w/in 5 years
a) 10%
b) 25%
c) 30%
d) 50%
e) 75%
d
Describe coronary artery disease
a heart disease that involves a build-up of plaque in one or more coronary arteries narrowing the radium of the BV and reducing the amount of blood that can reach the heart
What are coronary arteries?
the major arteries involved in supplying the heart w/ blood
Describe the difference b/w a heart attack and angina
unlike a heart attack, the coronary arteries in someone w/ angina are only partially blocked and thus can be treated with vasodilators
What is the significance of nitroglycerin wrt angina
it’s a vasodilator that can improve the blood flow in the partly restricted coronary arteries allowing for the heart to get enough blood supply
What is atherosclerosis?
a build-up of plaque in the arterial wall
What causes a myocardial infarction
heart attack = when the arteries are completely blocked preventing blood from reaching the heart
when the heart pumps inefficiently and can on longer meet the body’s need for blood. The _____ are often to blame for the insufficient flow
a) arteries
b) veins
c) atria
d) ventricles
e) more than one above
d
Describe the following
a) CAD
b) HCM
c) DCM
a) coronary artery disease = complete build-up of plaque in coronary arteries
b) hypertrophic cardiomyopathy = thickening of ventricular walls due to the muscle growth
c) dilated cardiomyopathy = the thinning of the ventricular walls causing the ventricle to expand
Describe what this image is showing
congestive HF = HF that causes a back-up of blood in the veins
What is the treatment for congestive HF?
Beta receptor blockers used to reduce the stress on the heart
