Week 8 // Heart

Question 1

heart is located inside these two things

answer is not thoracic cavity - more specific

Answer 1

Heart located in the mediastinum, behind sternum inside pericardial cavity

Question 2

The heart is enclosed and held in place by this

Answer 2

pericardial cavity

Question 3

The two layers of the pericardial cavity

Answer 3

Visceral layer of serous pericardium (towards heart)

Parietal layer of serous pericardium (towards chest)

Question 4

Three layers of the heart wall (superficial to deep)

Answer 4

epicardium, myocardium, and endocardium

Question 5

Peri, myo and endocarditis

Answer 5

Pericarditis – inflammation of pericardium
2 types: acute has no known cause, sometimes viral
and chronic begins gradually. Fluid increases between parietal and visceral layers in chronic swelling

Myocarditis – inflammation of myocardium
(usually viral) also… covid vaccine

Endocarditis – inflammation of endocarditis, usually bacterial and usually involves heart valves

Question 6

Layers of the pericardium

Answer 6

The pericardium consists of an outer fibrous pericardium and an inner serous pericardium

Question 7

Layers of the serous pericardium has 2 layers

Answer 7

Visceral

Parietal

Question 8

What are the chambers of the heart?

Answer 8

The chambers of the heart include two upper atria and two lower ventricles

Question 9

The superior vena cava comes from which portion of the heart?

Answer 9

The right atrium

Question 10

What does the right atrium do?

Answer 10

The right atrium receives blood from the superior and inferior vena cava and the coronary sinus

Question 11

What does the right ventricle do?

Answer 11

The right ventricle receives blood from the right atrium and sends blood to the lungs

Right A->V->

Question 12

Left Atrium?

Answer 12

The left atrium receives blood from the pulmonary veins

Question 13

Left Ventricle

Answer 13

The left Ventricle receives blood from the left atrium and sends blood all over the body (descending / ascending aorta)

Question 14

Note that the wall of the left ventricle is much thicker than that of the right ventricle – why?

Answer 14

Right ventricle only needs to send blood to lung, relatively short distance. Left ventricle must send farther - pumps blood for all of the body

Question 15

Vena cava (superior and inferior) - what do they do?

Answer 15

Vena cava (superior and inferior) collect blood full of carbon dioxide and send it to the heart so that it can be oxygenated

Question 16

oxygen rich blood comes back into the heart in the

Answer 16

left atrium

Question 17

oxygenated blood is sent the rest of the body from the

Answer 17

left ventricle

Question 18

fibrous skeleton in the heart

Answer 18

The fibrous skeleton of the heart:

• Forms the foundation for which the heart valves attaches
• Serves as a point of insertion for cardiac muscle bundles
• Prevents over-stretching of the heart valves
• Acts as an electrical insulator

Question 19

Heart valves

Answer 19

The valves of the heart open and close in response to pressure changes as the heart contracts and relaxes

Right and left atrioventricular valves
- Prevent back flow from the ventricles into the atria
Right and left semilunar valves
- Prevent back flow from the arteries into the ventricles

Question 20

When one set of valves is open, the other set is

Answer 20

closed

Question 21

flow of blood through heart and lungs from the vena cavas and the coronary sinus (veins) to the arteries

Answer 21

vena cava -> right atrium -> right ventricle -> pulmonary valve, pulmonary artery ->

pulmonary capillaries of LUNGS ->

pulmonary veins, left atrium, left ventricle, aorta and other arteries then veins then back to vena cava (etc.) again

Question 22

Myocardial Ischemia

Answer 22

Reduced blood flow to the myocardium
Can cause hypoxia (reduced oxygen supply) and angina pectoris (severe pain in the chest) and pain in the neck, chin, left arm and elbow

Question 23

Myocardial Infarction

Answer 23

(Also called Heart attack)
Infarction refers to death of tissues due to interrupted blood supply

Treatments include thrombolytic injection, coronary angioplasty or coronary artery bypass grafting

Question 24

Heart Conduction system

Answer 24

Cardiac muscle cells are self-excitable, and therefore auto-rhythmic. (No stimulation from outside.)

Cardiac muscle cells repeatedly generate spontaneous action potentials that then trigger heart contractions
These cells form the conduction system, which is the route for propagating action potentials through the heart muscle

Question 25

Artificial Pacemakers

Answer 25

Device that sends out small electrical currents to stimulate heart to contract Includes a battery and pulse generator Connected to 1 or 2 flexible leads threaded through superior vena cava and into chambers of the heart

Question 26

Influences on the Conduction System - things setting heart's pace

Answer 26

The auto-rhythmic fibers in the SA (sinuatrial) node are the natural pacemaker of the heart because they initiate action potentials most frequently Signals from the nervous system and hormones (like epinephrine) can modify the heart rate and force of contraction but they do not set the fundamental rhythm

Question 27

What is the Sinuatrial Node? *

Answer 27

The auto-rhythmic fibers in the SA (sinuatrial) node are the natural pacemaker of the heart because they initiate action potentials most frequently

Question 28

How do hormones and nervous system affect heart?

Answer 28

Signals from the nervous system and hormones (like epinephrine) can modify the heart rate and force of contraction but they do not set the fundamental rhythm (which is controlled by the Sinuatrial Node)

Question 29

Cardiac muscle generates _____ via anaerobic cellular respiration and creatine phosphate

Answer 29

ATP

Question 30

What is an EKG or ECG?

Answer 30

An EKG (Electrocardiogram) is a recording of the electrical changes that accompany each heart beat

Question 31

systole

Answer 31

contraction (systole)

Question 32

diastole

Answer 32

relaxation (diastole)

Question 33

One cardiac cycle consists of

Answer 33

One cardiac cycle consists of the contraction (systole) and relaxation (diastole) of both atria, rapidly followed by the systole and diastole of both ventricles ``` It includes: Electrical events Pressure changes Heart sounds Volume changes Mechanical events ```

Question 34

Cardiac Output *

Answer 34

C O is the volume of blood ejected from the left or right ventricle into the aorta or pulmonary trunk each minute

Question 35

Stroke volume

Answer 35

``` Stroke volume (SV) is the amount of blood pumped out of the ventricle in one beat C O (mL/min) = SV (mL/beat) × HR (beats/min) ```

Question 36

Three factors regulate stroke volume:

Answer 36

Three factors regulate stroke volume: Preload (before contraction, left ventricle - how much volume of blood inside the left ventricle.) Contractility (how well valves close and open and how strong heart pumps) Afterload (how much blood is left after pump, if too much, less stroke volume)

Question 37

What factors regulate heart rate?

Answer 37

``` Sinuatrial Mode Plus: several factors regulate heart rate: Autonomic nervous system Hormones Ions Age Gender Physical fitness Temperature ```

Question 38

Regular aerobic exercise can:

Answer 38

``` Increase cardiac output Increase HDL (high-density lipoproteins) Decrease triglycerides Improve lung function Decrease blood pressure Assist in weight control ```

Question 39

Cardiomyoplasty

Answer 39

A large piece of the patient's own skeletal muscle (left latissimus dorsi) is partially freed from connective tissue attachments and wrapped around the heart, leaving the blood and nerve supply intact. An implanted pacemaker stimulates the skeletal muscle's motor neurons to cause contraction 10-20 times per minute, in synchrony with some of the heartbeats.

Question 40

Skeletal muscle assist device

Answer 40

A piece of the patient's own skeletal muscle is used to fashion a pouch inserted between the heart and aorta, functioning as a booster heart. A pacemaker stimulates the muscle's motor neurons to elicit contraction.

Question 41

Ventricular assist device (VAD)

Answer 41

A mechanical pump helps a weakened ventricle pump | blood throughout the body so the heart does not have to work as hard