Blood

Question 1

Give the four primary fluids of the body and reference whether it is intracellular or extracellular

Answer 1

1. Intracellular fluid e.g. cytosol
2. Extracellular: blood, interstitial fluid (fluid between blood vessels and cells, and lymph

Question 2

Explain how blood is involved in cardiovascular transport

Answer 2

1. Gases
   -erythrocytes are red blood cells that transport O2 and CO2
2. Nutrients
3. Waste
4. Hormones

Question 3

Explain how blood is involved in regulation/homeostasis

Answer 3

1. PH regulation, buffering (pH 7.35-7.45)
2. Body temperature
3. Water balance

Question 4

Explain the protective functions of blood

Answer 4

1. Microorganisms
   -blood contains 5 types of white blood cells providing specific and non-specific immunity
2. Cancer cells
   -related to the immune system
3. Clotting/Wound repair
   -platelets facilitate clotting and thus repair

Question 5

Define how blood and blood plasma relate to connective tissue and extracellular matrix

Answer 5

1. Blood is specialised connective tissue composed of blood cells
2. Plasma is the extracellular matrix containing water, proteins/enzymes, hormones

Question 6

What is hematocrit

Answer 6

The percentage of the total blood volume occupied by centrifuged red blood cells

Question 7

How is the blood cell adapted to its function

What functions do blood cells forego as a result of its physiology

Answer 7

1. No nucleus
2. No mitochondria or ER
3. An elaborate cytoskeleton supporting its biconcave disk
4. Very flexible
5. Contain haemoglobin, where oxygen binds to one of the four haem groups per haemoglobin
6. Some CO2 bound on globulin
7. No anaerobic or aerobic respiration, thus no ATP generation
8. No protein synthesis
9. Thus unable to renew plasma membrane/organelle components
10. Live for four months

Question 8

Give description and processing of old red blood cells

Answer 8

1. Loss of membrane flexibility making them fragile and susceptible to rupture
2. Engulfed by phagocytosis, lymph nodes and bone marrow

Question 9

Give the consequences of excessive haemoglobin breakdown

Answer 9

1. Haemoglobin metabolism causes a buildup of bilirubin, a yellow coloured by-product
2. Insoluble in water and unable to be removed from the body it is toxic and causes brain damage
3. Bilirubin is converted to a water soluble bilirubin diglucoronide when added to glucoronic acid that can be expelled into intestine
4. Buildup results in jaundice
5. Triggered by gallstones, alcohol liver disease, pancreatitis, hepatitis, sickle cell anaemia

Question 10

Erythrocyte pathology

Answer 10

1. Membrane cytoskeleton defects lead to anemia, jaundice, enlarged spleen
2. Enzyme deficiencies lead to dysfunctional cells e.g. glucose-6-phosphate dehydrogenase, Pyruvate kinase
3. Haemoglobin defects in globin chains
4. Sickle cell anemia - E6V point mutation i.e. glutamic acid to valine mutation, recessive, 20 day lifespan, bilirubin production

Question 11

Describe B-thalassemia causes and symptoms

Answer 11

1. Inadequate HbA formation meaning pale and small RBCs (hypochromic, microcytic)
2. Aggregating a-globin chains aggregate on the membrane, damaging it
3. Excessive extra vascular hemolysis
4. Growth retardation, skeletal deformities, cardiac failure due to iron overload
5. Treatment: bone marrow transplant at early age