W01L04 Circulation of Blood

Question 1

Effects of sympathetic on CVS

Answer 1

Majority of blood vessels to constrict, sometimes dilate

Question 2

Effects of parasympathetic on CVS

Answer 2

Does not directly innervate blood vessels

Question 3

Left vs right ventricle

Answer 3

Left ventricle more muscular as it pumps to systemic circulation instead of just lungs

Question 4

Parallel arrangement

Answer 4

Allows independent regulation of blood flow and also ensures that every peripheral tissue/organ receives adequate fresh blood

Question 5

Normal amount of circulation at rest

Answer 5

5L per min

Question 6

Blood vessel vary in…

Answer 6

Number
Diameter
Wall thickness
Smooth muscle
Elastic tissue
Fibrous tissue

Question 7

Blood vessels are ALL

Answer 7

ALL lined by endothelial cells

Question 8

Functions of endothelial cells in blood vessels

Answer 8

Help regulate constriction and dilation of blood vessels and allow diffusion of nutrients/waste in the capillaries
Tone is regulated through the sympathetic system

Question 9

Mechanism of dilation of blood vessels

Answer 9

Through NO (Nitrous Oxide), the blood vessels are dilated, a factor relased by endothelial cells

Question 10

Smooth muscles are absent in…

Answer 10

Capillaries and venules there more no way to constrict capillary beds

Question 11

Blood flow is dictated by…

Answer 11

Arterioles and terminal arterioles because they have smooth muscle

Question 12

Reason for arteries to have an abundance of smooth muscle and elastic tissue

Answer 12

To accommodate high pressure

Question 13

Ultimate function of the cardiovascular system

Answer 13

To ensure adequate blood flow through the capillaries of various organs
10 billion capillaries 5L volume

Question 14

Trained athletes might have

Answer 14

Left ventricular hypertrophy

Question 15

4 Valves of the heart

Answer 15

Try Pulling My Big Aorta
Tricuspid valve
Pulmonary valve
Mitral (Bicuspid) valve
Aortic valve

Question 16

Atrioventricular (cuspid) valves

Answer 16

Tricuspid valve between right atrium and right ventricle
Mitral (bicuspid) valve between left atrium and left ventricle
Fairly flimsy
Attached to chordae tendineae
Valves open passively

Question 17

Chordae tendineae

Answer 17

Attached to 2/3 papillary muscles to prevent valvular prolapse

Question 18

Semilunar valves

Answer 18

Aortic valve between left ventricle and aorta
Pulmonary valve between right ventricle and pulmonary trunk
Heavy duty
Smaller openings, higher pressure, more stress and physical abrasion

Question 19

Cardiac muscle vs skeletal contraction

Answer 19

Skeletal can increase force of contraction because it can involve more motor units but with cardiac muscle all the cells are already involved with every contraction

Question 20

Features of cardiac muscle

Answer 20

Striated small fivers with individual nucleus
Connected via intercalated discs
Electrical connection through gap junctions (functional syncytium)
Desmosomes for cell to cell adhesion

Question 21

Functional syncytium

Answer 21

Cardiac muscles are made up of connected tissues that are chemically mechanically and electronically connected to one another, so they function together as one big muscle that is why they are called functional syncytium

Question 22

Haematocrit

Answer 22

% of blood volume that is erythrocytes (42-45%)

Question 23

% of active circulating blood

Answer 23

At any given moment, only 5% is actually in the capillaries to perform the ultimate functions of the entire CVS: supplying nutrients and removing metabolic end products and other cell secretions