Cardiovascular Anatomy (Lecture)

Question 1

What is artery?

Answer 1

• blood vessel that carries blood away from the heart
• usually oxygenated, exception is pulmonary arteries
• they gradually decrease in size from: arteries, arterioles to capillaries

Question 2

what are the three layers in the walls of arteries

Answer 2

1. Tunica externa or adventitia - outer layer
2. Tunica Media - middle or smooth muscle
3. Tunica Intima - inner layer with a smooth inner lumen, and elastic lamina to maintain shape

Question 3

Three types of arteries

Answer 3

1. elastic arteries
2. muscular arteries
3. arterioloes

Question 4

Elastic Arteries

Answer 4

• largest in size
• allow for a high degree of expansion between heart beats
• ex/ abdominal aorta

Question 5

Muscular arteries

Answer 5

• distributing arteries (main roads)
• regulate flow of blood to different parts of body

Question 6

Arterioles

Answer 6

• narrow lumina
• thick muscular walls (constriction/dilation)

Question 7

Capillaries

Answer 7

• simples endothelial tubes
• arranged in networks (capillary beds)
• O2, nutrients, CO2 and other materials are exchanges through diffusion

Question 8

What are veins

Answer 8

• return blood towards the heart
• usually deoxygenated, exception of pulmonary veins
• gradually increasing size of vessels (capillaries, venules, veins)
• they’re similar in structure to arteries, but the walls are thinner and have less developed muscle layer as there is lower blood pressure

Question 9

what are the three types of veins

Answer 9

1. small - unite to form venous plexus
2. Medium - have valves to maintain direction of flow, musculovenous pump
3. Large - wide bundles of smooth muscle, have valves, well deeloped tuniva adventitia

Question 10

Mediastinum

Answer 10

• middle space between two pulmonary cavities
• contains heart, great vessels, trachea, esophagus

Question 11

where is the heart located

Answer 11

• mediastinum
• covered on each side by a mediastinal pleura

Question 12

pericardium

Answer 12

• surrounds the heart
• double walled fibroserous sac enclosing the heart
• has two layers:
  1. fibrous pericardium: tough outer layer that stabilizes and prevents over-dilation
  2. Serous pericardium: lies within and directly covers heart
  i. parietal layer - more superficial
  ii. visceral layer - more deep
• between them is the pericardial cavity

Question 13

three tissue layers of heart

Answer 13

1. epicardium - thin external layer for lubrication; contains adipose and vessels
2. myocardium - thick middle layer for contraction (95-97% of heart wall)
3. endocardium - thin internal layers for protection

Question 14

sides of heart

Answer 14

• right side receives and sends deoxygenated blood
• left side receives and sends oxygenated blood

Question 15

Atria

Answer 15

• means entry hall
• smooth, thin walled interior
• musculi pectinati muscles for contraction and movement of blood vessels
• interatrial septum between atria

Question 16

Ventricles

Answer 16

• means little belly
• there are muscular elevations called trabeculae carneae that help produce a rigorous contraction
• left ventricle is more developed and thicker than the right
• chordae tendineae extend from papillary muscles to attach to the valves
• interventricular septum us string oblique partition

Question 17

atrioventricular valves

Answer 17

• tricuspid valve separates right atrium and right ventricle
• bicuspid (mitral) valve separates left atrium and left ventricle

Question 18

Semilunar valves

Answer 18

• pulmonary separates right ventricle and pulmonary trunk
• aortic separates left ventricle and ascending aorta

Question 19

what are the three steps of the cardiac cycle

Answer 19

1. period of diastole
2. atrial systole
3. ventricular systole

Question 20

what happens during diastole

Answer 20

• blood passively enters relaxed atria
• increased atrial pressure causes AV valves to open

Question 21

what happens during atrial systole

Answer 21

• ventricles remain in diastole
• atria contract
• blood is squeezed through AV valves into ventricles
• at the end the AV valves snap shut in response to the chordae tendineae and makes “LUB” sound

Question 22

ventricular systole

Answer 22

• atria enter diastole
• ventricles contract
• blood squeezed through semilunar valves into circulation
• at the end semilunar valves slam shut “DUB”

Question 23

what is the path of blood through the heart?

Answer 23

1. deoxygenated blood enters right atrium
2. travels through tricuspid valve to right ventricle
3. from right ventricle travels through pulmonary semilunar valve to pulmonary trunk
4. pulmonary trunk divides into L/R pulmonary arteries to each lung
5. oxygenated blood from the L/R sup/inf pulmonary veins enter left atrium
6. travels through bicuspid valve to left ventricle
7. from left ventricle travels through aortic semilunar valve to ascending aorta
8. aorta gives off brachiocephalic trunk, left common carotid, and left subclavian arteries

Question 24

Coronary Arteries

Answer 24

• first branches from aorta (heart eats first)
• supplies epicardium and myocardium
• right coronary artery supplies right atrium and most of right ventricle
• left coronary artery supplies left atrium and most of left ventricle

Question 25

Venous return in the heart

Answer 25

• great, middle, and small cardiac veins
• veins drain into coronary sinus which dumps into right atrium

Question 26

Arteries of the thorax

Answer 26

1. Intercostal arteries - branches from descending thoracic aorta and runs through costal groove of each rib
2. Internal thoracic arteries - branch from subclavian arteries