Chapter 6

Question 1

Layers of the heart

Answer 1

1. Epicardium - outside layer of connective tissue
2. Myocardium - middle layer of muscle
3. Endocardium - inner layer of smooth endothelium that lines the heart

Question 2

Heart chambers

Answer 2

2 atria (atrium) - receiving superior chambers of the heart, veins enter
2 ventricles- the inferior, discharging chambers of the heart, arteries leave

Question 3

Sinoatrial node (SA)

Answer 3

Small mass of tissue in the right atrium, functions as a pacemaker ie sets the pace of the action potentials (electrical signals) that initiate heart contractions

Question 4

Gap junctions

Answer 4

Allow action potentials to pass from one heart cell to another adjacent cell and allow the heart to contact in unison. A specialized intercellular connection which allow various molecules, ions and electrical impulses to directly pass between cells.

Question 5

Ectopic pacemaker

Answer 5

Any pacemaker in the heart other than the SA node

Question 6

Systole

Answer 6

Contraction of the ventricles

Question 7

Diastole

Answer 7

Relaxation of the ventricles

Question 8

Systematic circulation

Answer 8

Left side of the heart receives freshly oxygenated blood from the lungs via the pulmonary vein and pumps it to all the body cells via the aorta and systemic arteries

Question 9

The aorta

Answer 9

The main artery of the systemic circulation. It carries blood to all the other arteries except the pulmonary artery

Question 10

Systemic capillaries

Answer 10

Provide oxygen to all body’s cells

Question 11

Venae cavae

Answer 11

Largest veins in the body. They receive all the unoxygenated blood coming into the right heart

Question 12

Pulmonary circulation

Answer 12

The right heart pumps unoxygenated blood via the pulmonary arteries to the lungs, where oxygen is picked up and brought to the left heart via the pulmonary veins

Question 13

Coronary arteries

Answer 13

Encircle the heart. They flow through and feed the myocardium during diastole

Question 14

Shock

Answer 14

Critical condition caused by a sudden drop in blood flow through the body sharply curtailing the delivery of oxygen and nutrients to vital organs. Can be due to not enough volume or output by the heart. Hypotension, hyperventilation, weak rapid pulse, cold, clammy, grayish-blue skin, decreased urine flow and a sense of great anxiety and foreboding, confusion and sometime combativeness. Keep patient warm, give fluids by mouth or intravenously and drugs to improve cardiac and circulatory function.

Question 15

Hypotension

Answer 15

Low blood pressure

Question 16

Hyperventilation

Answer 16

Over breathing

Question 17

Cyanosis

Answer 17

Greyish-blueish skin

Question 18

Oliguria

Answer 18

Decreased urine flow

Question 19

Hypertension

Answer 19

Normally defined as a systolic pressure of 140 mm Hg or higher and/or diastolic pressure of 95 mm Hg or higher on tow are more measurements on two or more occasions

Question 20

Essential hypertension

Answer 20

Aka primary hypertension or idiopathic hypertension is hypertension that has no identifiable cause. The silent killer.

Question 21

baroreceptor

Answer 21

A sensory nerve ending in some large blood vessels. Eg, the common carotid artery of the neck that is sensitive to stretching of the arterial wall. The stretching results from changes in blood pressure.

Question 22

common carotid artery

Answer 22

Neck. Sensitive to stretching of the arterial wall

Question 23

Cardiac arrest

Answer 23

Indicates a sudden stop in effective and normal blood circulation due to failure of the heart to pump blood. Brain is the first organ effected. Loss of consciousness and breathing is shallow and minimized. Over 5 mins = permanent brain damage

Question 24

cardiac arrest causes

Answer 24

1. Myocardial infarction (heart attack)
2. Cardiac rhythm disturbance ( arrhythmia -most common fatal is ventricular fibrillation)
3. Extremely high or low body tempurature

Question 25

heart murmur

Answer 25

An abnormal continuous or periodic sound originating in the heart valves

Question 26

Atherosclerosis

Answer 26

Means clogging of the arteries. Fatty substances form a deposit of plaque on the inner lining of the arterial walls

Question 27

Ichemia

Answer 27

Loss of local blood flow due to mechanical obstruction

Question 28

Angina pectoris

Answer 28

Severe constricting pain (angina) in the chest (pectoris)due to ichemia of the heart muscle; usually caused by coronary disease

Question 29

Cell Necrosis

Answer 29

Cell death

Question 30

Ichemic necrosis

Answer 30

A death of an area of the heart muscle, usually results of occlusion (blocked) of a coronary artery

Question 31

Infarction

Answer 31

Cell death (necrosis) caused by a local lack of oxygen, due to an obstruction of tissue’s blood supply (ichemia). the resulting lesion is referred to as an infarct

Question 32

Lesion

Answer 32

A region in an organ or tissue that has suffered damage through injury or disease, such as a wound, ulcer, abscess or tumor

Question 33

Myocardial infarction

Answer 33

Death of some heart tissue and is commonly know as heart attack

Question 34

A-FIB

Answer 34

Atrial fibrillation - an abnormal heart rhythm characterized by rapid and irregular beating. Starts as brief periods of abnormal beating which become longer and possibly constant over time. Most episodes have no symptoms. Increases risk of heart failure, dementia and stroke. Hypertension is the most common alterable risk factor. Diagnosis by feeling pulse - confirmed my electrocardiogram ECG. AF often treaded with medications to slow HR to a normal range.

Question 35

Position for CPR

Answer 35

Supine - on the back

Question 36

Sternum

Answer 36

Breast bone

Question 37

AED

Answer 37

Automated external defibrillator - portable electronic devise that automatically diagnosis the life threatening cardiac arrhythmias of ventricular fibrillation and ventricular tachycardia

Question 38

fibrillation

Answer 38

Vermicular twitching of individual muscle fibres (vermicular = wormlike)

Question 39

Defibrillation

Answer 39

More successful if performed within 5 minutes of cardiac arrest and changes of survival decreases up to 10% for every minute that passes after the arrest