CVS

Question 1

How much blood does an average adult have?

Answer 1

5 litres

Question 2

What is the haematocrit?

Answer 2

The volume of blood that is composed of red blood cells.

Normally about 0.45.

Question 3

What is the life span of a red blood cell?

Answer 3

120 days

Question 4

What is the life span of a platelet?

Answer 4

7-10 days

Question 5

What bones make up the axial skeleton?

Answer 5

Skull, ribs, spine, pelvis, and long bones.

Question 6

What stimulates red blood cells to be made?

Answer 6

Erythropoietin (hormone made in the kidney)

Question 7

What stimulates white blood cells to be made?

Answer 7

Granulocyte colony stimulating factor (G-CSF)

Question 8

What stimulates platelets to be made?

Answer 8

Thrombopoietin (Tpo)

Question 9

What is an immature red blood cell known as?

Answer 9

A reticulocyte

Question 10

What type of antibodies are the anti-A and anti-B antibodies?

Answer 10

anti-erythrocyte antibodies (natural antibodies)

Question 11

What is the term used to describe a higher than normal haemoglobin level in the blood?

Answer 11

Polycthaemia

Question 12

Briefly describe iron deficiency anaemia.

Answer 12

Lack of iron results in the reduced proportion of small red cells.

Question 13

Briefly describe macrocytic anaemia.

Answer 13

Abnormally large red blood cells are released which are immature (red cells shrink as they mature).
These cells have low levels of haemoglobin.
Occurs due to B12/folate deficiency.

Question 14

Briefly describe pernicious anaemia.

Answer 14

Autoimmune disease causes antibodies to be produced against gastric parietal cells.
Less intrinsic factor released.
Less B12 absorption.
Less DNA synthesis and cell division.

Question 15

Define haemolysis.

Answer 15

Normal or increased cell production but decreased life span.

Question 16

What is acute myeloblastic anaemia?

Answer 16

Proliferation of the precursor myeloblasts.

Primarily affects adults.

Question 17

What is acute lymphocytic anaemia?

Answer 17

Proliferation of the lymphoblast precursor cells.

Primarily affects children.

Question 18

What is high grade lymphoma?

Answer 18

Lymphocytes in lymph nodes becoming malignant.

Question 19

What terms are used to describe high and low levels of platelets?

Answer 19

High = thrombocytosis
Low = thrombocytopenia

Question 20

Which clotting factors are vitamin K dependent?

Answer 20

II, VII, IX, and X

Question 21

What type of protein are coagulation factors?

Answer 21

Enzymes

Question 22

What is the main role of clotting factors?

Answer 22

Converts soluble fibrinogen to an insoluble fibrin polymer.

Question 23

Define haemostasis.

Answer 23

The arrest of bleeding, involving the physiological processes of blood coagulation and the contraction of damaged blood vessels.

Question 24

What is tissue factor?

Answer 24

Molecule present on every cell except endothelial cells which activates platelets.
When endothelium is breached proteins come into contact with tissue factor and are activated.

Question 25

What is the role of thrombin in the coagulation cascade?

Answer 25

It is the key enzyme that all the other reactions are aiming to generate. It cleaves fibrinogen creating fibrin polymerisation.

Question 26

Briefly describe disseminated intravascular coagulation (DIC).

Answer 26

Simultaneous bleeding and microvascular thrombosis.

Question 27

What causes a damage blood vessel to immediately constrict?

Answer 27

endothelin-1

Question 28

Which receptor on the surface of a platelet does Von Willebrand factor bind to?

Answer 28

Glycoprotein 1b

Question 29

Which receptors on the platelet does thrombin bind to?

Answer 29

PAR1 and PAR4

Question 30

Which platelet granules contain fibrinogen?

Answer 30

alpha granules

Question 31

What causes a damaged blood vessel to constrict after platelet activation?

Answer 31

Thromboxane A2

Question 32

Which two molecules does a healthy endothelium secrete which prevents the platelet plug expanding to an undamaged area?

Answer 32

``` Prostacyclin (vasodilator and inhibitor of platelet aggregatin) Nitric oxide (Vasodilator and inhibitor of platelet adhesion, activation, & aggregation) ```

Question 33

What is the role of blood clotting?

Answer 33

Occurs locally around the platelet plug to support and reinforce it.

Question 34

What is the difference between the extrinsic and intrinsic clotting pathways?

Answer 34

Extrinsic - a cellular element outside the blood is needed | Intrinsic - everything necessary is within the blood

Question 35

What causes the release of calcium from the sarcoplasmic reticulum?

Answer 35

Calcium ions that have entered the cell and travelled down the T tubules bind to ryanodine receptors on the sarcoplasmic reticulum and cause calcium release.

Question 36

How are calcium ions removed from the cardiac myocyte to end muscle contraction?

Answer 36

By active Ca++ pumps in the sarcoplasmic reticulum and sarcolemma. By Na+/Ca++ countertransporters in the sarcolemma (transport Na+ into the cell and Ca++ out of the cell).

Question 37

What is dextrocardia?

Answer 37

When the heart is on the right side of the chest instead of the left.

Question 38

If the veins are dilated what happens to the preload?

Answer 38

It decreases

Question 39

If the arteries are dilated what happens to the afterload?

Answer 39

It decreases

Question 40

What is intrinsic autoregulation?

Answer 40

The arterioles either vasoconstrict or vasodilate in response to changes in resistance with the aim of maintaining constant blood flow.

Question 41

Describe myogenic autoregulation.

Answer 41

Increased blood flow results in stretched vascular smooth muscle and the muscle automatically constricts. When smooth muscle isn't stretched as much (low blood pressure) the muscle relaxes and dilates.

Question 42

What is the main goal of central control of circulation?

Answer 42

Maintain mean systemic arterial pressure.

Question 43

What is the main goal of autoregulatory control of circulation?

Answer 43

Maintain constant blood flow to tissues.

Question 44

What is the pressor region?

Answer 44

Region in the medulla responsible for raising blood pressure. It is sympathetic.

Question 45

How does the pressor region work?

Answer 45

Increases vasoconstriction. Increases cardiac output (by increasing heart rate and stroke volume). Increases contractility.

Question 46

What is the depressor region?

Answer 46

Region in the medulla responsible for lowering blood pressure. It is parasympathetic.

Question 47

How does the depressor region work?

Answer 47

Inhibits the pressor region.

Question 48

Where are the cardiopulmonary baroreceptors located?

Answer 48

Located in the atria, ventricles, and pulmonary artery.

Question 49

What effects do the cardiopulmonary baroreceptors have?

Answer 49

When stimulated by high blood pressure: Inhibit the pressor region (vasodilation). Inhibit renin-angiotensin-aldosterone system (fluid loss). Inhibit ADH (fluid loss).

Question 50

How can adrenaline act as both a vasoconstrictor and vasodilator?

Answer 50

It can act on different receptors.

Question 51

Why is the pressure in the right side of a foetal heart greater than the pressure in the left?

Answer 51

The lungs and pulmonary circulation are non-functioning, so there is high pulmonary vascular resistance.