Blood

Question 1

Name the 3 groups of cells found in the blood

Answer 1

Erythrocytes, leukocytes and thrombocytes ( platelets).

Question 2

Name 5 white blood cells present in the blood, and state the main function of each

Answer 2

Neutrophils- phagocytise bacteria
Eosinophils- kill parasitic worms
Basophils- release histamine, heparin anticoagulant
Lymphocytes- amount immune response- direct cell attack or antibodies
Monocytes- develop into macrophages

Question 3

What is the sequence of events that prevents the loss of blood from blood vessels?

Answer 3

Haemostasis

Question 4

What is the most abundant plasma protein?

Answer 4

Albumin

Question 5

What are the 3 stages of Haemostasis?

Answer 5

1. Vascular spasms- vessel/capillaries constrict, vasoconstriction
2. Platelet plug formation- platelets adhere, release chemicals that make other platelets sticky, plug forms.
3. Fibrin forms a mesh- traps RBCs and platelets, forming clot.

Question 6

What is the fluid portion of the blood?

Answer 6

Plasma

Question 7

What is the red pigment in blood and what is it’s function?

Answer 7

Haemoglobin.

It’s function is to bind iron and oxygen in blood.

Question 8

What is the lifespan of erythrocytes?

Answer 8

120 days

Question 9

What does the intrinsic conduction system consist of?

Answer 9

Cardiac cells that initiate and distribute a wave of electricity throughout the heart.

Question 10

Where and how is iron stored in the body?

Answer 10

Liver, also in haemoglobin and ferritin-proteins in liver.

Question 11

What is a characteristic of anaemia?

Answer 11

A lack of intrinsic factor, which leads to a deficiency in vitamin B12 and formation of large pale cells called macrocytes.

Question 12

How many litres of blood due most adults have?

Answer 12

5-6 litres

Question 13

Define the terms End Diastolic Volume and End Systolic Volume?

Answer 13

EDV= the amount of blood that collects in a ventricle during diastole.

ESV= the volume of blood remaining in a ventricle after it has contracted.

Question 14

Define cardiac output?

Answer 14

Amount of blood pumped by each side of the heart in 1 minute.

Question 15

Define stroke volume?

Answer 15

Volume of blood pumped by each ventricle in one contraction.

Question 16

List and discuss the short term and long term mechanisms that regulate BP

Answer 16

SHORT TERM
Baroreceptors- sensory receptors that are sensitive to stretch. Detect small changes in BP. Depending on cause bradycardia/tachycardia

Adrenal Medullary Mech.- activated by substantial increase in sympathetic stimulation of heart & blood vessels; epinephrine-vasoconstriction; norepinephrine- vasodilation

Chemoreceptors- help maintains homeostasis when O2 decreases or CO2 & hydrogen increase. Hyperventilation.

CNS ischemic response- only activated in emergency/rare conditions. Acidosis? Increase peripheral resistance.

LONG TERM
Renin angiotensin-aldosterone: renin released by kidneys in response to low BP. Renin promotes angiotensin 2= vasoconstriction & aldosterone secretion.

ADH mech.- causes ADH release from post pituitary in response to low BP. Vasoconstriction & decreased urine output.

Atrial natriuretic mech.- a hormone released from cardiac cells in respond to high BP. Increase urine output= lower BV

Fluid shift mech.- movement of fluid between interstitial spaces and capillaries. Increase BV

Stress relaxation- adjustment of smooth muscle of blood cells in response to change in BP.