Circulatory System

Question 1

How does the body react to low Oxygen?

Answer 1

hormone erythropoietin is secreted from kidneys to go activate bone marrow to stimulate red blood cell production

Question 2

diastolic blood pressure

Answer 2

the bottom number

Heart muscles relax and fill with bloods returning to the heart via veins

because blood is not pumped from the heart, the volume of blood flowing through the arteries is lowered, decreasing pressure on the arterial walls

Question 3

systolic blood pressure

Answer 3

the top number

heart muscles contract and pump blood into arteries. This increases the volume of blood flowing into the arteries on contraction of the heart, increasing pressure on the arterial walls

Question 4

contraction of heart

Answer 4

pumps blood through vessels of the circulatory system, facilitating the delivery of oxygen and nutrients to tissues and the removal of waste products

blood moves away from heart through arteries and returns to the heart through veins

Question 5

Compared to the blood flowing into the left ventricle, the blood flowing into the right ventricle

Answer 5

is passing through a cardiac chamber with thinner walls so that it can pump blood at lower pressure to lungs

Question 6

Why does the left ventricle have thicker walls?

Answer 6

to pump blood at higher pressure to all body tissues except lungs

Question 7

right heart

Answer 7

pumps blood to the lungs to get oxygenated

receives deoxygenated blood from the tissues

Question 8

left heart

Answer 8

pumps blood to the rest of the body

receives oxygenated blood from the lungs

Question 9

Blood

Answer 9

fluid connective tissue in the body composed of living cells and nonliving plasma

contain both cellular portions and liquid portions

Question 10

cellular portion of blood

Answer 10

erythrocytes - transport oxygen
leukocytes - part of immune defense
platelets - help with blood clotting

Question 11

liquid portion of blood

Answer 11

about 90% water and 10% other substances

other substances: electrolytes (sodium, potassium, bicarbonate), respiratory gases (carbon dioxide and oxygen), hormones (insulin and glucagon), nutrients (glucose, amino acids), metabolic waste (urea), blood proteins (transferrin, albumin, antibodies, fibrinogen)

Question 12

What role does the liver play in blood clotting?

Answer 12

The liver produces clotting factors that are specialized proteins which are activated by platelet aggregation

Question 13

Process of blood clotting

Answer 13

1. Formation of the platelet plug occurs when the endothelial damage exposes connective tissue (fibrin)
   - platelets (derived from bone marrow) bind to collagen fibers and aggregate to form a platelet plug which will release signals that activate clotting factors
2. clotting factors are synthesized in the liver and released
   - these activate formation of thrombin which induces fibrin to form adhesive mesh structure to reinforce the clot

Question 14

endothelial cells

Answer 14

special types of cells that maintain vessel by releasing chemicals that aid in vasoconstriction and dilation

also allow white blood cells to pass through vessel wall and in tissues during inflammatory

also released chemicals when damaged that are involved in formation of blood clots to repair the vessel and stop bleeding