Cardiovascular lll

Question 1

Physiology - Circulatory System: What is the pathway of blood through the pulmonary circuit?

Answer 1

• Blood flows into the right atrium via the SVC + IVC.
• Right atrium
• Right ventricle (through atrioventricular tricuspid valve)
• Pulmonary artery (through pulmonary semilunar valve)
• Lungs (into arteries, arterioles, capillaries, venules, veins
• Pulmonary vein where blood enters into the systemic circulation system

Question 2

Physiology - Circulatory System: What is the pathway of blood through the systemic circuit?

Answer 2

• Blood enters via pulmonary vein
• Left atrium
• Left ventricle (through bicuspid/mitral valve)
• Aorta (through aortic semilunar valve)
• Into arteries of each organ
• Into arterioles, capillaries, venules, veins of each organ
• To vena cava - blood enters the circulatory system

Question 3

Foetal Circulation:
How does all nutrient, gas and oxygen exchange occur in a foetus?

Answer 3

Through the placenta. Lungs and digestive system are non-functioning in a foetus.

Question 4

Foetal Circulation:
How many veins/arteries does the umbilical cord carry?

Answer 4

One large umbilial vein, and two smaller umbillical arteries

Question 5

Foetal Circulation: What does the umbilical vein carry?

Answer 5

Blood rich in nutrients + oxygen to the foetus

Question 6

Foetal Circulation: What do the umbilical arteries carry?

Answer 6

Carbon dioxide + debris away from the foetus and into the placenta

Question 7

NOTE: Although extensive exchange between maternal and foetal blood components occurs, the blood of the mother and the foetus do not directly mix; instead, substances diffuse and exchange between the two sources of blood when they are adjacent at the placenta.

Question 8

How does blood move through the heart in the foetus (with non-functioning lungs)?

Answer 8

Blood is shunted directly from the right atrium through to the left atrium - there is no pulmonary circuit

Question 9

What is the definition of ‘arterial pulse’?

Answer 9

The alternating expansion and recoil of an artery that occurs with each beat + creates a pulse wave (aka a pulse)

Question 10

NOTE: normally pulse rate=heart rate. This can be changed by activity, postural changes and/or emotions

Question 11

Where can pulses be felt?

Answer 11

In any artery laying close to the body surface, by compressing the artery against firm tissue

Question 12

What is the most accessible pulse?

Answer 12

The radial pulse

Question 13

What are pressure points?

Answer 13

The same points of compressions as pulse points, that can be compressed distally to stop blood flow during significant blood loss

Question 14

Physiology - Blood Pressure: What is blood pressure defined as?

Answer 14

The pressure blood exerts against the inner walls of the blood vessels. Force that keeps blood circulating consistently even between heart beats. BP is understood to mean the pressure within the large systemic arteries near the heart.

Question 15

Which two arterial measurements can be made?

Answer 15

Systolic + Diastolic

Question 16

What defines systolic + diastolic in terms of measuring blood pressure?

Answer 16

Systolic - The pressure in the arteries at the peak of ventricular contraction
Diastolic - The pressure in the arteries at the peak of ventricular relaxation

Question 17

How is BP measured indirectly?

Answer 17

Via the ausculatatory method (measured at the brachial artery)

Question 18

What is blood pressure directly related to?

Answer 18

CO (cardiac output - the amount of blood pumped out of the heart heart over the course of a minute), and PR (peripheral resistance - which defines the amount of friction the blood encounters as it flows through the vessels)

Question 19

What is peripheral resistance in the context of blood pressure?

Answer 19

The amount of resistance blood encounters as it flows through the vessels

Question 20

What is the main factor that increases peripheral resistance?

Answer 20

The constriction of blood vessels (vasoconstriction)

Question 21

Which part of the nervous system can cause an increase in peripheral resistance via vasoconstriction?

Answer 21

The sympathetic nervous system. Vasoconstriction can occur due to fright, haemorrhge, or standing up (as blood can pool in the legs)

Question 22

What is atherosclerosis? How can it impact on peripheral resistance?

Answer 22

Atherosclerosis is a disease which causes a buildup of plaque (composed of cholesterol + fat) in the arteries, which can restrict blood flow + in turn increase peripheral resistance of BP through constriction of arterial space.

Question 23

What are the main three ways that vasoconstriction can occur; causing an increase in peripheral resistance

Answer 23

• Sympathetic nervous system causing vasoconstriction
• Atherosclerosis causing vasoconstriction through plaque buildup
• Increased blood volume/viscosity increase PR

Question 24

Physiology: Blood Pressure Factors
Renal factors - How do kidneys play a role in regulating blood pressure?

Answer 24

By altering blood volume. The kidneys can control water reabsorption or filtering (thus altering blood volume)

Question 25

Physiology: Blood Pressure Factors Renal Factors Which enzyme do the kidneys release when blood pressure is low? How does the enzyme function?

Answer 25

Renin. Renin functions by triggering a series of chemical reactions, forming angiotensin - a potent vasoconstricter (peptide hormone).

Question 26

Physiology: Blood Pressure Factors Temperature Factors How does temperature influence blood pressure?

Answer 26

Vaconstriction/dilation of blood vessels. (Heat causes vasodilation where cooler temperatures may cause vasoconstriction).

Question 27

Physiology: Blood Pressure Factors How do chemicals influence blood pressure?

Answer 27

The effects of chemicals can be widespread. - Epinephrine/Adrenaline increases both HR and BP - Chemicals like Nicotine increase BP through vasoconstriction - Alcohol and histamine cause vasodilation and reduce BP

Question 28

Physiology: Blood Pressure Factors How does diet impact on blood pressure?

Answer 28

Diets high in salt, sat. fats and cholesterol can cause plaque build up in arteries (leading to atherosclerosis)

Question 29

Physiology: Blood Pressure Variations NOTES: BP varies with age, weight, mood, posture, race and physical activity What are some examples of blood pressure variations?

Answer 29

- Hypotension (low BP) - Orthostatic Hypotension (low BP caused by varying factors) Hypertension - (High BP)

Question 30

At what point/number is a systolic BP considered to be hypotension? type of hypotension?

Answer 30

A systolic number under 100 generally is considered as hypotension. Generally this is not a cause for concern, as it is an expected result of physical conditioning and age free illness.

Question 31

What is orthostatic hypotension? What are some causes?

Answer 31

Orthostatic hypotension is a type of hypotension that occurs due to standing up after a long period of sitting/recling. Aging, or a slow sympathetic nervous system can cause orthostatic hypotension.

Question 32

What is chronic, and acute hypotension? What causes each?

Answer 32

Chronic refers to an experienced disorder over a long period of time, where acute refers to a sudden or rapid onset. - Chronic hypotension may hint at poor nutrition or inadequate blood protein levels - Acute hypotension is an important warning of circulatory shock - usually from blood loss

Question 33

What is hypertension? At what arterial pressure is hypertension normally classified?

Answer 33

High blood pressure. Can be caused due to pathological conditions. Brief elevation is normal and can be caused due to exercise, fever, emotions etc. Defined as an arterial pressure above 140/90 or higher. *is a common and dangerous disease that warns of increased peripheral resistance. Heart is forced to pump against a greater resistance, in time the myocardium enlarges, and can be strained against capacity.***

Question 34

Physiology - Ageing: NOTES

Answer 34

Ageing changes are different to disease related changes so must be distinguished from cardiovascular disease With increasing age, there is a tendency towards replacement of normal structures/tissues with collagen and fibrous tissue. Both the myocardium and the heart valves are affected. With age, blood vessels lose their compliance (including aorta), which can increase the tendency to develop high blood pressure (hypertension). Increased left ventricular load (overcome lower compliant arteries) and afterload can cause left ventricular hypertrophy, increasing systolic BP

Question 35

Physiology - Aging: What are some changes in the conduction system that affect HR?

Answer 35

- Changes in the conduction system impulses can affect heart rate. In some cases there is a loss of self paced pacemaker cells. - Baroreceptors can become less sensitive, compromising the body's capacity to effectively respond to sudden changes in BP - There is decreased responsiveness to beta-adrenergic receptor stimulation and an increase in catecholamine secretions

Question 36

Physiology - Disorders: What is Pericarditis? What causes it?

Answer 36

Pericarditis is the inflammation of the pericardium (the sac surrounding the heart). Can be caused by various factors: trauma, viral or bacterial infection, tumours, and other factors. Can be acute or chronic

Question 37

Physiology - Disorders: What is Rheumatic heart disease? What causes it?

Answer 37

Can be caused from a delayed/improper treatment of a streptococcal infection/strep throat/scarlett fever. Can result in stenosis or other deformities of valves, chordae tendineae or myocardium and inflammation.

Question 38

Physiology - Disorders: What is mitral valve prolapse? What causes it?

Answer 38

Mitral valve prolapse is a heart condition where the valve flaps between the left upper and lower heart chambers bulge backward during the heart's contraction, sometimes allowing blood to leak back. Mainly caused by genetics (myxomatous degeneration), but can originate from rheumatic fever.

Question 39

Physiology - Disorders: What is Aortic regurgitation? What causes it?

Answer 39

Caused by leaky aortic semilunar valve, blood regurgitates back into the left ventricle. Causes volume overload, subsequent hypertrophy and increase in contraction strength to compensate. Can lead to MI (myocardial infarction/heart attack) through decreased blood flow causing muscle cell impairment. Caused by congenital heart defects, aging and infections.

Question 40

Physiology: Disoders Pericarditis - NOTES Pericarditis - The pericardial oedema that characterizes this condition often causes the visceral and parietal layers of the serous pericardium to rub together—causing severe chest pain. Pericardial fluid, pus, or blood (in the case of an injury) may accumulate in the space between the two pericardial layers and impair the pumping action of the heart. This is termed pericardial effusion and may develop into a serious compression of the heart called cardiac tamponade – fluid build up in the spaces around the heart.

Question 41

Physiology: Disorders What is coronary artery disease? What causes it?

Answer 41

Coronary artery disease = buildup of plaque (a substance made of fat, cholesterol, and other substances) inside the coronary arteries, leading to their narrowing and hardening, a process called atherosclerosis, which restricts blood flow to the heart. Similar to atherosclerosis but specifically focusing on the arteries to the heart. Can be caused by diet and cholesterol.

Question 42

Physiology: Disorders What defines the term 'cardiomyopathy'?

Answer 42

A term that describes a number of different types of heart diseases that result in abnormal enlargement

Question 43

Physiology: Disorders What is Angina pectoris? What causes it?

Answer 43

When the myocardium is deprived of sufficient oxygen, coronary arteries are limited in function. (from latin angina=tightening/to choke, pectoris=chest)

Question 44

Physiology: Disorders What is heart failure? What causes it?

Answer 44

Heart failure describes the inability of the heart to pump enough blood to sustain life. It is often measured as a decline in the ejection fraction (EF) below normal. The lower the EF, the more severe the heart failure.

Question 45

Physiology: Disorders What is congestive heart failure? What causes it?

Answer 45

Defines simply left sided heart failure. It is the inability of the left ventricle to pump blood effectively. Most often, such failure results stem from chronic systemic hypertension (high BP), or by myocardial infarction caused by coronary artery disease

Question 46

Physiology: Disorders Congestive heart failure - NOTES

Answer 46

It is called congestive heart failure because it decreases pumping pressure in the systemic circulation, which in turn causes the body to retain fluids. Portions of the systemic circulation thus become congested with extra fluid. Left-sided heart failure also causes congestion of blood in the pulmonary circulation, termed pulmonary oedema —possibly leading to right-sided heart failure and pulmonary hypertension