vitale 1

Question 1

3 serous membranes generated by a tissue called mesothelium

Answer 1

-pleurae (2) around the lungs
-pericardium (1) around the heart
-peritoneum (1) around some organs of the abdomen

Question 2

where does gas exchange take place during fetal life?

Answer 2

in the maternal placenta

Question 3

what happens when the umbilical vessels are cut?

Answer 3

there is a shift from the fetal respiration (gas exchange in the maternal placenta) to adult respiration and it happens in a few seconds

Question 4

big autonomic innervation of the heart?

Answer 4

the cardiac plexus that comprehends both sympathetic and parasympathetic nerves

Question 5

congenital heart defects

Answer 5

failures that can happen during heart development (complex process that is ongoing until birth)

Question 6

the cardiac plexus don’t ? but regulates?

Answer 6

heart beating–>regulated by the cardiac plexus but autonomically generated inside the heart

Question 7

what is the main histological component of the heart?

Answer 7

cardiac muscle

Question 8

why can we say that the heart is a directional pump?

Answer 8

because it has valves that, by opening and closing, give directionality to the blood flow

Question 9

what’s the name of the diffusion of the electrical stimulus that generate contraction inside the heart?

Answer 9

conduction system: the system by which the electrical stimulus generated inside the heart diffuses to the whole organ

Question 10

systolic phase

Answer 10

the phase in which the heart contracts and blood is pushed inside the arteries

Question 11

diastolic phase

Answer 11

the heart is relaxed and the blood is coming back inside the cavities through veins

Question 12

arteries

Answer 12

vessels that bring blood away from the heart

Question 13

veins

Answer 13

vessels that bring blood back inside the heart

Question 14

capillary system

Answer 14

-allows exchange of substances from the blood to the different organs
-can not exist by itself: blood has to be pushed into the capillaries by arteries and it has to go back to the heart by veins
-the wall of the capillaries is very thin and specialized because it has to allow exchange of substances in both ways (from the blood to the organ and from the organ to the blood)
-we have billions of capillaries because they have to reach each and every cell in each organ

Question 15

conduction vessels

Answer 15

-all the vessels of the circulatory system but the capillaries

Question 16

which system is a low pressure system?

Answer 16

venus system

Question 17

which system is an high pressure system?

Answer 17

arterial system

Question 18

three segments of the system circulation

Answer 18

-the venus
-the arterial
-the capillaries

Question 19

in which vessel we can say that there is the highest pressure?

Answer 19

at the beginning of the aorta

Question 20

in which vessels can we say that there is the lowest pressure?

Answer 20

in the two vessels (vene cavae, superior and inferior) that bring back blood to the heart

Question 21

pulmonary circulation

Answer 21

-smaller than the general one
-arteries bring deoxygenated blood to the lungs->carbon dioxide is expirated and oxygen is uploaded from the alveoli to the capillaries

Question 22

lungs receive 2 circulations

Answer 22

1) pulmonary circulation (dedicated to gas exchange)
2) bronchial circulation, proper vessels of the lungs as organs

Question 23

efferent vessels

Answer 23

away from the heart, arteries

Question 24

afferent vessels

Answer 24

back into the heart, veins, that arise from the convergence of capillaries

Question 25

what allow substances and gas exchange between blood and tissues?

Answer 25

capillaries each capillary diameter is very small but we have billions of them-->the overall diameter of the capillary system is humongous, the global exchange surface with tissues is very big

Question 26

why is the global volume of capillaries bigger than the global volume of any other vessel?

Answer 26

because you want to slow down the blood flow rate to allow substances and gas exchange with the tissues

Question 27

why are capillaries so thin?

Answer 27

because the exchange rate is proportional to the contact area between blood cells and plasma and the endothelium of the vessel. The thinnest is the capillary, the highest is the area of contact, the highest is the exchange rate of substance

Question 28

what separates the right and the left side of the heart?

Answer 28

the cardiac septum

Question 29

what are the arteries that vascularize our heart?

Answer 29

coronary arteries

Question 30

elastic fibers and smooth muscle cells composition along the vessels

Answer 30

increased number of elastic fibers in the aorta and progressive decrease of elastic fiber as we go up with the quantity and down with the diameter of the specific vessels