Body Fluids and Circulation

Question 1

From where to where do arteries transport blood? What type of blood do they transport?

Answer 1

• From the heart to the rest of the body
• Carry mostly oxygenated blood

Question 2

From where to where do veins transport blood? What type of blood do they transport?

Answer 2

• From the rest of the body to the heart
• Carry mostly deoxygenated blood

Question 3

From where to where do capillaries transport blood? What type of blood do they transport?

Answer 3

• Capillaries connect arteries and veins
• They carry both oxygenated and deoxygenated blood

Question 4

Are the walls of arteries thick + why?

Answer 4

Arteries have thicker walls and blood flows through them with higher pressure

Question 5

Are the walls of veins thick + why?

Answer 5

Veins have thinner walls and blood flows through them with low pressure

Question 6

Are the walls of capillaries thick + why?

Answer 6

Capillaries have walls only one cell thick for diffusion

Question 7

Arteries, veins, capillaries- valves?

Answer 7

Arteries- no valves
Veins- Have valves
Capillaries- no valves

Question 8

Speed of blood in arteries and veins

Answer 8

Arteries- blood speed fast
Veins- blood speed slow

Question 9

Tricuspid valve- location + allows blood to flow from

Answer 9

location: right atrioventricular septum

allows blood to flow from: right atrium to right ventricle

Question 10

Bicuspid valve/mitral valve- location + allows blood to flow from

Answer 10

location: left atrioventricular septum

allows blood to flow from left atrium to left ventricle

Question 11

Pulmonary valve- location + allows blood to flow from

Answer 11

location: at the origin of the pulmonary artery in the right ventricle

allows blood to flow from right ventricle into the pulmonary artery

Question 12

Systemic valves/Aortic valves- location + allows blood to flow from

Answer 12

location: at the origin of the systemic aorta

allows blood to flow from the left ventricle into the systemic aorta

Question 13

Duration of one cardiac cycle

Answer 13

0.8 second

Question 14

Contraction of heart chambers

Answer 14

Systole

Question 15

Relaxation of heart chambers

Answer 15

Diastole

Question 16

Atrial systole

Answer 16

• Duration- 0.1 sec
• Deoxygenated blood (low pressure) enters right atrium
• Oxygenated blood enters left atrium
• Contraction of atria
• Blood flows into ventricles
• Atria act as a pump to collect and force blood into the ventricles

Question 17

Atrial diastole

Answer 17

The atrium relapses

Question 18

Ventricular systole

Answer 18

• Duration- 0.3 sec
• Ventricles contract
• Atrioventricular valves close (causing LUB sound)
• Ventricular pressure rises and exceeds blood pressure in the aorta and the pulmonary artery
• Aortic and pulmonary valves open
• Blood drained out from the ventricles into the vessels
• At the end of ventricular systole, ventricular diastole begins

Question 19

Ventricular diastole

Answer 19

• Pressure falls in the ventricles
• High pressure in the aorta and pulmonary artery forces a small amount of blood towards the ventricles, thus closing the semi-lunar valves (causing DUP sound)
• Atria and ventricles continue joint diastole (Cardiac diastole - 0.4 second)

Question 20

How is systolic pressure measured by a sphygmomanometer?

Answer 20

• Air is pumped into the cuff until the pressure is sufficient to stop the flow of blood in the branchial artery. No sound is heard.
• The doctor then slowly releases air until he hears the first pulse.
• Pressure of air in the cuff is slightly lesser than the pressure of the blood in the branchial artery. (>120 mm Hg)
• The reading that is noted is the systolic pressure

Question 21

How is diastolic pressure measured by a sphygmomanometer?

Answer 21

• The doctor releases a little more air after measuring the systolic pressure, stopping at the point when no more sound is heard (<80 mm Hg)
• The reading is noted
• This is the diastolic pressure

Question 22

Heart rate

Answer 22

Heart rate is the rate at which the cardiac muscles contract and relax rhythmically. Thus, the heart rate of a healthy adult at rest is normally 70-75 per minute.

Question 23

Pulse

Answer 23

Pulse is a wave felt along the wall of an artery due to the contraction of the left venticle. Pulse is the heart rate i.e. the number of times the heart beats per minute.
Normal pulse rate is 60-100 beats per minute

Question 24

What is cardiac output?

Answer 24

• Measure of blood volume ejected from the heart over a given time
• It maintians blood flow throughout the body
• Determined by multiplying heart rate by stoke volume (CO= SV * HR)
• 5.25 L/min

Question 25

What is heart rate? | formula + value

Answer 25

Heart rate: Number of beats/ min 75 beats/min

Question 26

Stroke volume | Definition + value

Answer 26

Amount of blood ejected from the ventricles during one heartbeat 70 mL/beat

Question 27

ECG | full form + definition

Answer 27

ECG (Electrocardiogram) is a graphical representation of the electrical activities of the heart during a cardiac cycle

Question 28

P-Wave

Answer 28

Depolarisation of atria in response to sinoatrial (SA) node triggering | little bump at the start

Question 29

PR Interval

Answer 29

Delay of AV (atrioventricular) node to allow filling of ventricles | little flat thing after P wave

Question 30

QRS complex

Answer 30

Depolarization of ventricles, triggers main pumping contractions | tall mountain part

Question 31

ST Segment

Answer 31

Beginning of ventricle repolarization, should be flat | flat part after QRS complex

Question 32

T-Wave

Answer 32

Ventricular repolarization | little bump at the end

Question 33

Composition of blood

Answer 33

* Plasma- 55% * Formed elements- 45%

Question 34

Composition of plasma

Answer 34

* Proteins- 7% (Albumins, Globulins, Fibrinogen, Prothrombin- blood coagulation) * Water- 91% * Other solutes- 2% ( Ions, nutrients, waste products, gases, regulatory substances)

Question 35

Composition of formed elements of blood

Answer 35

* Platelets <1% * Leukocytes (WBCs) <1% * Erythrocytes (RBCs) >99%

Question 36

Leukocytes: classification

Answer 36

**Agranulocytes** Lymphocytes- 20-25% Monocytes- 3-8% **Granulocytes** Neutrophils- 60-70% Eosinophils- 2-4% Basophils- 0.5-1%

Question 37

Blood coagulation: process

Answer 37

* At injury site, the tissues release platelets and clotting factor prothrombin activator (Thrombokinase) and calcium ions * Prothrombin activator converts prothrombin to thrombin * Thrombin in turn converts fibrinogen into fibrin * Fibrins form mesh like structure in which red blood cells get trapped * Clot is formed and bleeding stops

Question 38

Hypertension

Answer 38

* Disorder of the circulatory system * High blood pressure above the normal 120/80 mm/Hg

Question 39

Coronary Artery Disease | Mention coronary heart disease

Answer 39

* Disorder of the circulatory system * The coronary arteries become narrow, reducing the blood flow to the heart * This results in Coronary Heart Disease, a condition in which the heart muscle is damaged because of an inadequate supply of blood due to obstruction of its blood supply.

Question 40

Angina pectoris Symptoms, definition

Answer 40

Definition: Attacks of choking or throttling pain across the upper part of the chest due to reduction in blood flow through the coronary arteries which supply heart muscles is known as angina pectoris. Symptoms * Chest pain (angina) * Fatigue * Shortness of breath * Cold sweats

Question 41

Cardiac arrest/Heart failure Cause and symptoms

Answer 41

Heart is not pumping blood effectively enough to meet the needs of the body Cause: Usually triggered by a problem with the heart's electrical impulses Symptoms: * Loss of consciousness * No pulse or breathing

Question 42

Myogenic heart

Answer 42

* In myogenic heart, the cardiac movement is initiated rhythmically by cardiac muscles themselves. * Acetylcholine inhibits the heart beat. * This type of heart is found in molluscs and vertebrates

Question 43

Who was the pacemaker first used by?

Answer 43

Chardack

Question 44

What is a pacemaker?

Answer 44

A tiny computerised electrical device that is implanted in the patient's body to regulate heart beat. Electrodes from it are usually connected to the right ventricle.

Question 45

Neurogenic heart

Answer 45

* Cardiac movement is initiated by nerves arising from the brain * Heart of all invertebrates except molluscs