Exam 1: Hematopoiesis stuff

Question 1

Define hematopoiesis.

Answer 1

Blood cell development and production

Question 2

What 4 structures in the body are involved in hematopoiesis?

Answer 2

1. Bone marrow
2. Spleen
3. Lymph nodes
4. Thymus

Question 3

Describe the development of hematopoiesis at this stage:

2 weeks old

Answer 3

• yolk sac

- primitive (erythroblast)

Question 4

Describe the development of hematopoiesis at this stage:

2 months old

Answer 4

liver and spleen

Question 5

Describe the development of hematopoiesis at this stage:

7 months old

Answer 5

• bone marrow

- most bones are filled with erythroid cells

Question 6

Describe the development of hematopoiesis at this stage:

Birth

Answer 6

• hematopoiesis stops in the liver and spleen
  # now only occurs in bones
• about 90% of bone marrow is active (red)

Question 7

Describe the different types of bone marrow.

Answer 7

1. Red
     # active
2. Yellow
     # inactive
     # adipocytes

Question 8

Describe the development of hematopoiesis at this stage:

4 years old

Answer 8

• long bones (ex: femur, tibia) begin having fat cells

- inactive/yellow

Question 9

Describe the development of hematopoiesis at this stage:

18 – 20 years old

Answer 9

- hematopoiesis is reduced to 60% active/red
     # sternum
     # ribs
     # pelvis
     # vertebrae
     # skull
- the rest is 40% inactive/yellow

Question 10

Describe the development of hematopoiesis at this stage:

40 years old

Answer 10

• hematopoiesis is reduced to 50% active/red
• thus, fat and red marrow are equal in these areas:
  # sternum
  # ribs
  # pelvis
  # vertebrae
  # skull

Question 11

Describe the development of hematopoiesis at this stage:

> 55 years old

Answer 11

- hematopoiesis is reduced to 40% active/red in these areas:
     # sternum
     # ribs
     # pelvis
     # vertebrae
     # skull

Question 12

Where is the best spot for retrieving bone marrow?

Answer 12

iliac crest

Question 13

Explain extramedullary hematopoiesis.

Answer 13

• when bone marrow stops doing all the work

- the liver/spleen kicks back into action just like old times