Lecture #7

Question 1

Flow is governed by two main variables, what are they?

Answer 1

1. Pressure
   - impels fluid to move
   - According to pressure gradient (high to low)
2. Resistance
   - opposes flow

Question 2

Auscultation

Answer 2

Listening to sounds made by the body

Question 3

S1 Lub

Answer 3

AV valves

Question 4

S2 (Dub)

Answer 4

SL Valves

Question 5

Pulmonary Edema

Answer 5

1. Right Ventricle output exceeds left ventricle output
2. Pressure backs up
3. Fluid accumulates in pulmonary tissue

Question 6

Systemic Edema

Answer 6

1. Left Ventricle output exceeds right ventricle output
2. Pressure backs up
3. Fluid accumulates in systemic tissue

Question 7

Cardiac Output

Answer 7

CO=HR(SV)

Volume of blood pumped per unit time

Question 8

Cardiac Output can be modified by either term:

Answer 8

1. Heart Rate (HR)
   - Modulated by nervous and endocrine system
   - bradycardia (<60bpm)
   - Tachycardia (>100bpm)
2. Stroke Volume (SV)
   - volume of blood pumped with each beat
   - preload, contractility, and after load

Question 9

Heart rate is regulated by?

Answer 9

Cardiac centers in the Medulla of the brain
1. Proprioceptors are responsible for activating muscles and joints

2. Baroreceptors (pressure receptors)
   are responsible for detecting changes in blood pressure, include the aorta and internal carotid arteries
3. Chemoreceptors are responsible for detecting blood pH, CO2, and O2, in Aortic arch, carotid arteries, medulla

Question 10

Autonomic Nervous systtem

Answer 10

• influence the rate of impulse generation (firing), depolarization/depolarization of myocardium
• Influence strength of atrial and ventricular contraction
• influence changes in the heart and circulatory system faster than metabolic or humoral agents

Question 11

Vagal Tone

Answer 11

Parasympathetic, slower heart rate between 70-80bpm

• if all sympathetic and parasympathetic stimulations or nerves are damage heart will continue beating at 100bpm

Question 12

Blood Flow

Answer 12

• the amount of blood flowing through an organ, tissue, or blood vessel in a given time (mL/min)

Question 13

Perfusion

Answer 13

the passage of fluid per given volume or mass of tissue in a given time (mL/min/g)

Question 14

Flow of blood thought the body

Answer 14

• is constant and is equal to the cardiac output (5.25L/min)

- flow through individual organs varies from minute to minute

Question 15

Hemodynamics

Answer 15

Physical principles of blood flow based on pressure and resistance

1. the greater the difference between two points, the greater the flow
2. the greater the resistance = less flow

Question 16

Blood Pressure

Answer 16

is the force that blood exerts against a vessel wall

BP declines with distance from the heart

• arterial elasticity
• friction on vessel wall

Question 17

Where is Blood Pressure measured?

Normal Value

Answer 17

brachial artery of the arm using sphymomanometer

= 120/75mmHg

Question 18

Two pressures are recorded

Answer 18

1. Systolic Pressure - peak arterial BP taken during ventricular contraction
2. Diastolic Pressure - minimum arterial BP taken during ventricular relaxation (diastole)

Question 19

Pulse Pressure

Answer 19

difference between systolic-diastolic pressure

Question 20

Mean Arterial Pressure (MAP)

Answer 20

• the mean pressure, takes measurements at several intervals throughout the cardiac cycle

MAP = diastolic pressure + 1/3 (Pulse Pressure)

Question 21

What is Atherosclerosis?

Answer 21

Fat build up inside the arteries (plaque)

• progressive conditions lead to coronary artery disease and peripheral artery disease

Question 22

Define Hypertension

Answer 22

High blood pressure
BP>140/90
- can weaken arteries, cause aneurysms, promote atherosclerosis

Question 23

Define Hypotension

Answer 23

chronic low resting BP

- caused by blood loss, dehydration and anemia

Question 24

What are the factors contribute to blood pressure

Answer 24

1. Cardiac Output - the amount of blood pumped out by the heart per minute
2. Blood Volume
   - regulated by the kidneys
3. Resistance to Flow

Question 25

Peripheral Resistance

Answer 25

the opposition to flow that blood encounters in vessels away from the heart

Question 26

What are the factors that influence resistance?

Answer 26

1. Blood Viscosity (Thickness) - increased mainly from RBC count and albumin 2. Vessel length - more friction it encounters the father it goes - pressure and flow declines with distance 3. Vessel Radius - most powerful influence over flow

Question 27

Laminar Flow

Answer 27

flows in layers, faster in the center. small changes in blood vessel radius can cause large change in flow

Question 28

Vasoconstriction

Answer 28

when smooth muscle of tunica media contracts

Question 29

Vasodilation

Answer 29

relaxation of the smooth muscle, allowing blood pressure to expand vessel

Question 30

Peripheral Resistance | Aorta to capillaries

Answer 30

Blood velocity decreases from aorta --> capillaries because: 1. increase distance = more friction -- lower speed 2. decreased radii of vessels = more resistance 3. Greater corss-sectional area because the # of vessel increase

Question 31

Peripheral Resistance From capillaries -- > vena cava velocity increase because:

Answer 31

1. Veins are larger = less resistance than capillaries 2. Convergence of vessels large amounts of blood into smaller channels BLOOD IN VEINS NEVER REGAIN VELOCITY IT LOST

Question 32

Vasoreflexes

Answer 32

are quick and powerful ways of regulating blood pressure and flow

Question 33

Two purposes of dilation and constriction are?

Answer 33

1. General control of BP throughout the whole body | 2. Method of rerouting blood from one region to another for perfusion of individual organs

Question 34

What are the 3 ways of controlling vasomotor activity?

Answer 34

1. Local Control 2. Neural Control 3. Hormonal Control