Circulatory System

Question 1

types of circulatory system:

Answer 1

close circulatory system - blood closed at all times within vessels of different size and wall thickness

open circulatory system - common mostly in anthrops and mollusks

Question 2

Specific Functions of the Circulatory System:

Answer 2

• distribution of nutrients
• transportation and exchange of oxygen and carbon dioxide
• removal of waste materials
• distribution of endocrine secretions
• prevention of excessive bleeding
• prevention of infection
• regulation of body temperature

Question 3

The cardiovascular system:

Answer 3

consists of heart and blood vessels that send blood to:
lungs for oxygen
digestive system for nutrients

CV system also circulates waste products to certain organ systems for removal from the blood

Question 4

The Heart: Structures

Answer 4

• Cone-shaped organ about the size of a loose fist
• In the mediastinum
• Extends from the level of the second rib to about the level of the sixth rib
• Slightly left of the midline

Question 5

Covers the heart and large blood vessels attached to the heart

Answer 5

Pericardium

Question 6

• Innermost layer
• Directly on the heart

Answer 6

Visceral pericardium

Question 7

Layer on top of the visceral pericardium

Answer 7

Parietal pericardium

Question 8

Heart walls:

Answer 8

Epicardium
* Outermost layer
* Fat to cushion heart

Myocardium
* Middle layer
* Primarily cardiac muscle

Endocardium
* Innermost layer
* Thin and smooth
* Stretches as the heart pumps

Question 9

Four chambers:

Answer 9

Two atria
* Upper chambers
* Left and right
* Separated by interatrial septum

Two ventricles
* Lower chambers
* Left and right
* Separated by interventricular septum

Question 10

prevents blood from flowing back into the right atrium when the right ventricle contracts

Answer 10

Tricuspid valve

Question 11

prevents blood from flowing back into the left atrium when the left ventricle contracts

Answer 11

Bicuspid valve

Question 12

prevents blood from flowing back into the right ventricle

Answer 12

Pulmonary valve

Question 13

prevents blood from flowing back
into the left ventricle

Answer 13

Aortic valve

Question 14

Cardiac Cycle
Influenced by:

Answer 14

• Exercise
• Parasympathetic nerves
• Sympathetic nerves
• Cardiac control center
• Body temperature
• Potassium ions
• Calcium ions

Question 15

First Sound

Answer 15

Lubb

Question 16

Second sound

Answer 16

Dubb

Question 17

Wall of the right atrium: Natural pacemaker
and sends impulse to AV node

Answer 17

Sinoatrial node (SA node)

Question 18

Between atria just above ventricles that sends impulse to the bundle of His

Answer 18

Atrioventricular node (AV
node)

Question 19

Between ventricles
Two branches
Sends impulse to Purkinje fibers

Answer 19

Bundle of His

Question 20

• Lateral walls of ventricles
• Ventricles contract

Answer 20

Purkinje fibers

Question 21

Group of structures that send electrical impulses through the heart

Answer 21

Cardiac Conduction System

Question 22

Arteries

Answer 22

• Strongest of the blood vessels
• Carry blood away
  from the heart

Under high pressure
* Vasoconstriction
* Vasodilation

Question 23

Small branches of arteries

Answer 23

Arterioles

Question 24

Takes blood from the heart to the body

Answer 24

Aorta

Question 25

Supply blood to heart muscle

Answer 25

Coronary arteries

Question 26

Veins

Answer 26

**Blood under no pressure in veins** * Does not move very easily * Skeletal muscle contractions help move blood * The sympathetic nervous system also influences the pressure * Valves prevent backflow

Question 27

Capillaries

Answer 27

* Branches of arterioles * The smallest type of blood vessel * Connect arterioles to venules * Only about one cell layer thick * Oxygen and nutrients can pass out of a capillary into a body cell * Carbon dioxide and other waste products pass out of a body cell into a capillary

Question 28

How do arteries control blood pressure?

Answer 28

The muscular walls of arteries can constrict to increase blood pressure or dilate to decrease blood pressure.

Question 29

Blood Pressure

Answer 29

**Force blood exerts on the inner walls of blood vessels** * Highest in arteries * Lowest in veins

Question 30

* Ventricles contract * Blood pressure is at its greatest in the arteries

Answer 30

Systolic pressure

Question 31

* Ventricles relax * Blood pressure in arteries is at its lowest

Answer 31

Diastolic pressure

Question 32

It is located in the aorta and carotid arteries. It also help regulate blood pressure

Answer 32

Baroreceptors

Question 33

What is the difference between the systolic pressure and diastolic pressure?

Answer 33

**systolic pressure:** contraction of ventricles increasing the pressure in the arteries. **diastolic pressure:** the result of the relaxation of the ventricles lowering the pressure in the arteries.

Question 34

Pulmonary circuit

Answer 34

right atrium 🡪 right ventricle 🡪 pulmonary artery trunk 🡪 pulmonary arteries 🡪 lungs 🡪 pulmonary veins 🡪 heart (left atrium)

Question 35

Systemic circuit

Answer 35

left atrium 🡪 left ventricle 🡪 aorta 🡪 arteries 🡪 arterioles 🡪 capillaries 🡪 venules 🡪 veins 🡪 vena cava 🡪 heart (right atrium)

Question 36

Carry oxygen-rich blood away from the heart

Answer 36

Arterial system

Question 37

Carries oxygen-poor blood toward the heart

Answer 37

Venous system

Question 38

Collection of veins carrying blood to the liver

Answer 38

Hepatic portal system

Question 39

carry oxygen-poor blood

Answer 39

Pulmonary arteries