Blood

Question 1

What is the blood

Answer 1

A fluid type of connective tissue
Composed of plasma (55) & cells (45)
Accounts for 7% body weight

Question 2

Functions of the blood

Answer 2

Contributes to homeostasis by transporting o2, co2, nutrients, wastes & hormones
Helps regulate pH & temperature
Immune function with antibodies, phagocytes, clotting factors etc

Question 3

What is blood plasma

Answer 3

The yellow coloured liquid that remains when cells are removed from blood
Consists of:
Mostly water (91)
Proteins (7)
Mineral salts (0.9)
Nutrients
Organic waste materials
Hormones
Enzymes
Gases

Question 4

How is blood plasma separated from blood cells

Answer 4

With the use of a centrifuge, where blood is spun to separate the contents based on density

Question 5

What is serum

Answer 5

Blood plasma with clotting factors removed

Question 6

What are hepatocytes

Answer 6

Liver cells

Question 7

What are the three proteins found in blood plasma

Answer 7

Albumin
Globulins
Fibrinogen

Question 8

Nutrients found in blood plasma

Answer 8

Simple sugars (carbohydrates) mostly glucose
Amino acids (building blocks for proteins)
Fats/oils - carried by lipoproteins
Vitamins

Question 9

What are cations

Answer 9

Mineral components found in blood plasma
Positively charged ions
Eg sodium, potassium, calcium, magnesium

Question 10

What are anions

Answer 10

Mineral component found in blood plasma
Negatively charged ions
Chlorides, bicarbonates, phosphates

Question 11

Haematopoiesis

Answer 11

Production of all blood cells

Question 12

Haematocrit

Answer 12

The percentage of blood volume occupied by erythrocytes

Question 13

How much oxygen can a haemoglobin molecule hold

Answer 13

4 polypeptide chains (globin) each bound to a haem pigment (iron) which can carry 1 oxygen molecule so in total one haemoglobin molecule can carry 4 oxygen molecules
HbA = two alpha & two beta

Question 14

Why is blood red

Answer 14

Due to the interaction & chemical bonds of iron & oxygen & the way they reflect light

Question 15

What causes hypoxia

Answer 15

Below normal blood cell levels stimulates kidneys to release hormone ‘erythopoietin’ to stimulate erythopoiesis

High altitude, haemolysis (blood destruction), blood loss, pregnancy

Question 16

What is erythropoiesis

Answer 16

Formation of erythrocytes in red bone marrow (erythropoietin hormone stimulates this)

Question 17

What is Haemolysis

Answer 17

The destruction of erythrocytes to release haemoglobin into plasma which is carried out by macrophages, found especially in the spleen, bone marrow & liver

Question 18

What is bilirubin

Answer 18

A by-product pigment formed from the breakdown of haem
It is predominately formed in the spleen, bone marrow & liver
It must be conjugated in the liver for it to be effectively excreted in the GIT (mostly in faeces through bile where it is turned into sturcubilin)

Question 19

What is the ABO blood group

Answer 19

Glycolipid antigens A&B located on the surface of erythrocytes which form 4 human blood groups A, B, AB, O
O=no antigen flags thus universal donor
AB=universal recipient can receive any blood group

Question 20

What is a transfusion reaction

Answer 20

The immune system makes antibodies against antigens it doesnt recognise that can cause haemolysis

Question 21

What is the rhesus factor blood group

Answer 21

Surface antigen found on erythrocytes inherited via a dominant gene

Question 22

What is the haemolytic disease of the newborn

Answer 22

Where baby is rhesus positive & mum is rhesus negative - mums immune system attacks baby’s blood if they come into contact eg by a haemorrhage or in second child birth due to females exposure to rhesus & bodys production of anti-bodies against the antigen

Anti-rhesus antibodies can be injected to inactivate foetal rhesus antigens

Question 23

What nutrients are required for erythropoiesis

Answer 23

Vitamin B12, folate (B9) & iron

Question 24

Two types of leukocytes

Answer 24

Granulocytes (secretory granules in cytoplasm)
Agranulocytes (no granules in cytoplasm)

Leukocytes function to defend the body from microbes & foreign particles & account for 1% blood volume

Question 25

What 3 cells are found in granulocytes & what are their functions

Answer 25

1. Neutrophils (account for 60%) - 1st to migrate to infection site, phagocytosis die & form pus 2. Basophils (account 1%) - key inflammatory cells, release histamine & hepanin 3. Eosinophils (account 2-4%) - eliminate parasites

Question 26

What 2 cells are found within agranulocytes & what are their functions

Answer 26

1. Monocytes (account 6%) - inflammation & repair, activate other immune cells via antigen presentation 2. Lymphocytes (account 30%) = B-lymphocytes, T-lymphocytes & Natural killers - critical for immunity against specific antigens, Bs make antibodies whilst Ts & NKs kill

Question 27

The production process of thrombocytes

Answer 27

Megakaryoblasts transform into megakaryoctyes which breakdown into thrombocyte fragments Which are Produced under thrombopoeitin hormone (mostly from liver)

Question 28

What are thrombocytes 4 stage blood clotting process

Answer 28

1. Vasoconstriction - thromboxane is released 2. Platelet plug formation- positive feedeback system where platelet aggregation (stickiness) increases to stick to cell wall & release binding hormones 3. Coagulation (clotting factors) - reinforce platelet plug with the enzyme thrombin converting fibrinogen into fibrin which are long sticky threads that create a mesh & a clot forms 4. Fibrinolysis - breakdown of a clot, enzyme plasmin

Question 29

How does the hormone thromboxane help blood clotting process

Answer 29

1st phase vasoconstriction - When collagen is exposed to vascular endothelium, thromboxane is released which causes smooth muscles to contract to help strengthen blood clotting

Question 30

How does the enzyme thrombin help blood clotting process

Answer 30

3rd phase coagulation- Thrombin converts fibrinogen into fibrin which are long sticky threads that create a mesh over site of injury & cause a clot to form

Question 31

How does the enzyme plasmin help the process of blood clotting

Answer 31

4th stage fibrinolysis- Plasmin can dissolve clots by digesting threads & inactivating fibrinogen & thrombin

Question 32

Normal male & female haemoglobin ranges

Answer 32

``` Males = 13-18 g/dL Females = 11.5-16.5 g/dL Preganancy = >11 g/dL ```

Question 33

What are some key functions of cholesterol

Answer 33

Cell membrane integrity (vital in brain) Vitamin D & calcium metabolism Sex hormones eg testosterone & oestregen

Question 34

What are low density lipoproteins (LDLs)

Answer 34

Carry 75% total cholesterol in blood, carryibg it from the liver to cells of the body When present in excess LDLs deposit cholesterol in arteries

Question 35

What are High density lipoproteins (HDLs)

Answer 35

Remove excess cholesterol from body cells & blood & transport back to the liver Help prevent cholesterol accumulation in blood

Question 36

How does the blood contribute to skin homeostasis

Answer 36

Delivers clotting factors & white blood cells to aid repair when the skin is injured Changes in blood flow to the skin is used to adjust body temp

Question 37

How does blood contribute to skeletal system homeostasis

Answer 37

Delivers bone minerals & hormones to control bone remodelling & RBC production (erythropoietin) to the bone

Question 38

How does blood contribute to muscular system homeostasis

Answer 38

Blood transports heat & lactic acid from the muscles

Question 39

How does blood help maintain body homeostasis

Answer 39

Skeletel, skin, muscular system Endocrine, lymphatic/immune system, respiratory system, digestive system, urinary system & reproductive system Delivery & distribution of substances for all