Chapter 7.1

Question 1

Where does oxygenated blood enter the heart

Answer 1

-it enters the heart through pulmonary veins

Question 2

Are the ventricles more muscular than the atria? If yes, then what does this mean?

Answer 2

• yes they are

- >this allows for more powerful contractions necessary to push blood through the rest of the cardiovascular system

Question 3

What is the valve between the right ventricle and right atrium referred to as

Answer 3

-it is referred to as the tricuspid valve

Question 4

What is the valve between the left atrium and the left ventricle known as

Answer 4

-it is known as the mitral or bicuspid valve

Question 5

What is the order of electrical impulses travelling through cardiac muscle

Answer 5

1) SA node
- >starts the impulse initiation

2) AV node
- >sits at the junction of the atria and ventricles

3) Bundle of His
- >embedded in the interventricular septum

4) Purkinje fibers
- >distributes the electrical signal through the ventricular muscle

Question 6

What is atrial kick? How does it result

Answer 6

• additional volume of blood from the atrium into the ventricles is atrial kick
• > note that this is due to an atrial systole or contraction of the atrium that results in an increase of the atrial pressure
• > this increased pressure results in a little more blood into the ventricles

Question 7

What happens to the valves during systole?

Answer 7

-ventricles contract and AV valves close and blood is pumped out of the ventricles

Question 8

What happens to the valves during diastole?

Answer 8

• heart is relaxed

- >the semilunar valves are closed and blood from the atria fills the ventricles

Question 9

What is cardiac output? What is cardiac output for humans?

Answer 9

• it is the total blood volume pumped by a ventricle in a minute
• note the volume of blood passing through each side of the heart must be the same

-for humans, cardiac output is generally about 5 liters per minute

Question 10

What are all blood vessels lined with? What type of cells

Answer 10

-they are lined with endothelial cells

Question 11

What is the purpose of endothelial cells

Answer 11

1) releases chemicals that aid in vasodilation and vasoconstriction
2) Allows white blood cells to pass through the vessel wall and into tissues during an inflammatory response
3) Also help in releasing certain chemicals that are necessary in the formation of blood clots

Question 12

Describe the general characteristics of capillaries

Answer 12

• vessels with single endothelial cell layer
• > so small that red blood cells pass in a single file line
• > note that gases, nutrients(glucose) and wastes pass through capillaries

Question 13

Describe the general characteristics of veins

Answer 13

• thin walled
• > inelastic
• > smaller amount of smooth muscle than arteries so less recoil
• larger veins contain valves
• > doesn’t allow for backflow of blood

Question 14

What is a deep vein thrombosis

Answer 14

-it is a clot in the deep vein thrombosis

Question 15

What is the hepatic portal system

Answer 15

-blood leaving the capillary bed in the gut passes through the hepatic portal vein before reaching the capillary beds in the liver

Question 16

What is the pathway of the hypophyseal portal system

Answer 16

-blood leaving the capillary bed in the hypothalamus goes to a capillary bed in the anterior pituitary

Question 17

What is the pathway of the renal portal system

Answer 17

-blood leaving the glomerulus travels through an efferent arteriole