L5: Heart 2

Question 1

a large, smooth-walled portion of the right atrium

Answer 1

sinus venarum

smooth, thin and not very contractile

Question 2

musculi pectinati is part of..

Answer 2

right auricle

forms the anterior part of the chamber

Question 3

the junction between the right auricle(musculi pectinati) and sinus venarum is called…

Answer 3

crista terminalis

Question 4

a small depression located in the interatrial septum of the heart. It is a remnant of a fetal structure that served a vital function during fetal development.

Answer 4

fossa ovalis

Question 5

function of valve of inferior vena cava

Answer 5

in the embryo helped direct oxygenated blood coming into the right atrium to the foramen ovale

Question 6

fossa ovalis used to be…

Answer 6

foramen ovale

Question 7

main pumping component of the receiving right chamber is…

Answer 7

right AURICLE( thicker and stronger musculi pectinati)

atrial contraction- auricle doing most of the work

sinus venarum is quite thin and does not contribute much to the squeezing of the blood

Question 8

what is one way of testing the health of the right side of the heart?

Answer 8

jugular venous pressure

can insert a pressure probe through a central line(commonly internal jugular vein) and make the pressure probe come down to the lvl of transthoracic plane: perfect spot to measure pressure spikes in the venous side(right chamber): jugular venous pressure( when the atria contract pressure is higher) also detects the health of the valves

Question 9

atrioventricular valves attach to…

Answer 9

fibrous skeleton

Question 10

1 papillary muscle helps control how many casps?

Answer 10

half of 2 neighbouring casps

Clinically: if papillary muscle fails it affects half of 2 valve leaflets( not just 1)

Question 11

chordae tendinae are attached to…

Answer 11

papillary muscles

Question 12

muscle arrangement in the ventricles is called

Answer 12

trabeculae carneae

Question 13

septomarginal trabecula runs from…

Answer 13

from interventricular septum to anterior papillary muscle

Question 14

specialised beam of trabecula muscle in the right ventricle

Answer 14

septomarginal trabecula (moderator band)

Question 15

moderator band
(what it is, function)

Answer 15

The moderator band, also known as the septomarginal trabecula, is a muscular structure that is found in the right ventricle of the heart. It is a distinctive muscular ridge that extends from the interventricular septum to the base of the anterior papillary muscle.

The moderator band has several important functions in the heart:

Electrical Conduction: The moderator band contains specialized myocardial fibers that conduct electrical signals. It helps to rapidly conduct electrical impulses from the right bundle branch to the anterior papillary muscle, ensuring synchronous contraction of the ventricles.

Support for the Tricuspid Valve: The moderator band provides additional support to the tricuspid valve, which separates the right atrium from the right ventricle. It helps to maintain the proper position and tension of the tricuspid valve leaflets during ventricular contraction, preventing backflow of blood into the right atrium.

Blood Flow Regulation: The presence of the moderator band affects blood flow dynamics within the right ventricle. It helps to divert blood from the inflow region to the outflow region of the right ventricle, facilitating efficient ejection of blood into the pulmonary artery.

Question 16

a cone-shaped structure located at the base of the right ventricle in the heart. It is the transitional region between the right ventricle and the pulmonary trunk, which is the main artery that carries deoxygenated blood from the heart to the lungs.

Answer 16

conus arteriosus

Question 17

Answer 17

Question 18

right atrioventricular valve is a ____ valve

Answer 18

tricuspid

Question 19

why do we have 4 pulmonary veins?

Answer 19

as the atrial wall enlarged
parts of the pulmonary veins go on to form smooth part of the atrium

Question 20

how to tell pulmonary and aortic valve apart

Answer 20

aortic valve have coronary ostea

Question 21

what are the 2 main things that cause heart murmurs?

Answer 21

1. Stenosis(narrowing)
   e.g. artic stenosis in rheumatic fever patients- opening becomes more narrow. More wooshing sound

2.Regergetation
valves leak. Hear wooshing sound.

Question 22

why is the stiffening of the interventricular septum important during ventricular depolarisation

Answer 22

want it to stiffen just before the outer parts of the wall start to contract, to protect the right ventricle. R. ventricle is weaker than the left and when left ventricle contracts it can distort the inlet of the right ventricle causing it to leak.

Question 23

another name for Purkinje fibers

Answer 23

subendocardial branches

Question 24

why does one of the Purkinje fibers goes out to make a moderator band and stimulate papillary m?

Answer 24

want papillary m to be activated before the ventricle contracts so that they are ready

Question 25

sympathetic activity/effects in the heart:

Answer 25

increase HR
increase contraction
increased BP
vasodilate coronary arteries( BUT vasoconstriction of peripheral vessels to increase BP)

Afferent:
referred pain: chest, arm etc. Not precise.

Question 26

Parasympathetic activity/effects in the heart:

Answer 26

decrease HR, BP

vasoconstriction of coronary arteries

Afferent:
does not contribute to pain
monitors BP, blood chemistry etc.