Blood Histology

Question 1

List the functions of blood.

Answer 1

1. Transportation e.g. oxygen, hormones
2. Regulation e.g. body temp., pH
3. Protection e.g. contains leukocytes and antibodies

Question 2

Describe the appearance of erythrocytes.

Answer 2

• Biconcave
• Disc shaped
• No nucleus

Question 3

What is the function of erythrocytes?

Answer 3

Transport oxygen from the lungs to body tissues and return carbon dioxide from tissues to the lungs.

Question 4

What are the five different leukocytes?

Answer 4

Neutrophils, lymphocytes, monocytes, eosinophils and basophils.

Question 5

Describe the appearance and function of each type of leukocyte.

Answer 5

Neutrophils: Multilobed nucleus, granular; responsible for phagocytosis of pathogens.
Lymphocytes: Large, round nucleus, agranular; include T cells and B cells, which play key roles in adaptive immunity.
Monocytes: Kidney-shaped nucleus, agranular; differentiate into macrophages, which phagocytize pathogens and dead cells.
Eosinophils: Bilobed nucleus, granular; respond to parasitic infections and allergic reactions.
Basophils: Large, irregular nucleus, granular; release histamine and heparin, involved in inflammatory responses.

Question 6

Describe the appearance and function of platelets.

Answer 6

• Small, disc-shaped cell fragments.
• Release chemicals that activate clotting factors, leading to the formation of a stable blood clot to prevent blood loss.

Question 7

Describe and explain the three steps to the removal of RBCs.

Answer 7

1. Phagocytosis: Macrophages in the spleen and liver engulf and break down aged or damaged erythrocytes.
2. Hemoglobin Breakdown: Hemoglobin is split into heme and globin. Globin is broken down into amino acids, while heme is converted to biliverdin and then bilirubin, which is excreted in bile.
3. Iron Recycling: Iron from hemoglobin is recycled and transported back to the bone marrow by the protein transferrin to be used in new red blood cell production.