Unit 1 Lecture

Question 1

What are the three components of the cardiovascular system?

Answer 1

• The heart: which acts as a pump to propel….
• Blood: which moves through tubes called….
• Blood vessels: which conduct blood throughout the body

Question 2

What does the circulation of blood look like in the heart?

Answer 2

Circulation is continuous with two trips through heart before returning to where you started. The heart is thus often called a double pump.

Question 3

What is the heart often called?

Answer 3

A double pump

Question 4

What is each stop at the heart?

Answer 4

Each stop at the heart is the end of a separate circuit

(Heart -> arteries -> capillaries -> veins -> heart)

Question 5

What are the two cardiovascular circuits?

Answer 5

Question 6

What does each side of the heart contain?

Answer 6

It contains an atrium and a ventricle. Blood enters into the heart at an atrium and is ejected out of the heart from a ventricle.

Question 7

Discuss systemic circuit

Answer 7

• Carries oxygenated blood (“arterial blood:) to body cells/tissues/organs
• Begins with the left ventricle of the heart (ejects blood into the aorta) and ends with the right atrium (collects returning blood)
• Distributes blood in a parallel manner. Major recipients of blood include: kidneys, GI system, skeletal muscle, brain, skin, liver, bone, and heart

Question 8

Discuss the pulmonary circuit (Pulmonary Circulation)

Answer 8

• Carries de-oxygenated blood (“venous blood”) to the lungs where it is reloaded with oxygen (and emptied of excess carbon dioxide) before returning to the heart
• Begins with the right ventricle of the heart (ejects blood into the pulmonary trunk) and ends with the left atrium (collects the returning blood)
• Requires proper functioning of the respiratory system

Question 9

What does blood flow with?

Answer 9

Blood flows with a concentration gradient

-Blood has more pressure at the start where it is pushed out

Question 10

Study the circulation of blood

Answer 10

Question 11

What is cardiac output?

Answer 11

It is the amount of blood pumped by a ventricle per unit time (measured in L/min)

Question 12

Does the systemic or pulmonary circuit have a faster cardiac output?

Answer 12

Both systemic and pulmonary circuits have the same cardiac output. (Left and right ventricles eject the same amount of blood)

-It is equal to about 5 L/min under resting conditions

Question 13

Does cardiac output change?

Answer 13

Cardiac output changes to meet the needs of the body. CO can be increased as much as 30 L/min during maximal exercise

Question 14

What is a heart and what is it composed of?

Answer 14

• Is composed primarily of cardiac muscle
• Is a double pump
• Contains 4 chambers
• Directs blood flow by means of 4 valves
• Is suppled with blood by the first two arteries formed off of the aorta

Question 15

What are the four chambers of the mammmalian heart? And how does blood move through them?

Answer 15

1. Right atrium (RA)
2. Left atrium (LA)
3. Right ventricle (RV)
4. Left ventricle (LV)

Question 16

What do the atria and ventricles do?

Answer 16

The atria recieves blood; the ventricles force blood out of the heart into systemic and pulmonary circuits

Question 17

Which ventricle has more muscle and why?

Answer 17

Due to the difference in workload, the left ventricle has much more muscle (is much thicker) than the right ventricle.

Question 18

Why does blood happen to move only in one direction (always into atria, then ventricles, and then out of the heart)?

Answer 18

Heart valves

Question 19

Discuss heart valves

Answer 19

• There are four “one-way” heart valves
• Heart valves ensure that blood flows through the heart in only one direction
• There are two between the atria and ventricles (left and right atrioventricular valves)
• There are teo semilunar valves (one between LV and aorta, and the other between RV and pulmonary trunk)

Question 20

What is the left Atrioventricular Valve called and what does it separate?

Answer 20

The left AV is also called the bicuspid valve (“two cusps”) or mitral valve

-It separates the left atrium and left ventricle

Question 21

What is the right Atrioventricular Valve called and what does it separate?

Answer 21

The right AV is also called the tricuspid valve (“three cusps”)

-Separates the right atrium and right ventricle

Question 22

What are chordae tendinae, what do they do, what do they prevent?

Answer 22

• The tissue flaps of the AV have tendons known as chordae tendinae
  
  • Chordea tendinae attach the valve cusps to the inner ventricular walls
  • Chordae tendinae prevent “prolapse” of the valves into the atria during ventricular contraction

Question 23

What do papillary muscles do?

Answer 23

Specialized muscles, known as papillary muscles, regulate tension in the chordae tendinae and contract simultaneously with the ventircles

Question 24

What does the aoritc semilunar valve do?

Answer 24

The aortic semilunar valve separates the left ventricular chamber from the aorta

Question 25

What does the pulmonary semilunar valve do?

Answer 25

The pulmonary semilunary valve separates the right ventricular chamber from the pulmonary trunk

Question 26

How do the aortic semilunar valve and pulmonary semilunar valve open and close?

Answer 26

These valves open in a pressure-dependent manner, meaning that they open and close in response to pressure differences between the major vessels and heart ventricles

Question 27

Commonality between AV and Semilunar valves?

Answer 27

AV valves open and close together and same with semilunar valves

Question 28

Summarize CV circulation

Answer 28

Question 29

Summary of the internal anatomical features of the heart

Answer 29

Question 30

What is coronary circulation?

Answer 30

Coronary circulation is the part of systemic circulation that provides itself with blood. Collateral routes (anastomoses) ensure blood delivery to heart tissue even if major vessels are occulded. The tissues of the heart are supplied wiht blood from the right and lefr coronary arteries

Question 31

Where do right and left coronary arteries originate?

Answer 31

Right and left coronary arteries originate on the ascending aorta

Question 32

Discuss the right coronary artery

Answer 32

Question 33

Discuss the left coronary artery

Answer 33

Question 34

Regarding coronary circulation, what does the great cardiac vein do?

Answer 34

The great cardiac vein drains the anterior heart

Question 35

Regarding coronary circulation, what does the middle cardiac vein do?

Answer 35

The middle cardiac vein drains the posterior heart

Question 36

Regarding coronary circulation, what does the coronary sinus do?

Answer 36

Borth middle and great cardiac veins drain into the coronary sinu which in turn drains into the right atrium

Question 37

What are the two types of congestive heart failure?

Answer 37

* Diastolic: heart cant fill * Systolic: heart cant pump

Question 38

What is congestive heart failure caused by?

Answer 38

* Cardiovascular disease * Hypertension

Question 39

What does cardiac muscle consist of?

Answer 39

Cardiac muscle consists of branched, striated fibrt with one or two centrally located nuclei

Question 40

What are actin and myosin?

Answer 40

Actin and myosin are packaged in myofibrils, in the same arrangement as thet are in skeletal muscles; its sarcmeres

Question 41

Why do the cardiac muscles contain a branching pattern?

Answer 41

Branching pattern, which forms a network that can facilitate the transmission of electrical impuses in all directiosn

Question 42

What are gap junctions?

Answer 42

* Gap junctions are small channels which allow electrical impulses to pass quickly from one cell to the next * Gap junctions are located in "intercalated discs" which lie between adjacent mucle fibers * Intercalated discs also contain desmosomes, which hold adjacent cells toegther