Cell differentiation (continued)

Question 1

Name the layers of the skin?

Answer 1

Dermis.
Epidermis.
Hypodermis.

Question 2

What is the dermis made of? (4 things)

Answer 2

Collagen (strength and suppleness).
Sensory receptors (activated by touch/pressure/pain).
Hair follicles + nail beds.
Elastic fibres (elasticity and resilience).

Question 3

Which 3 highly specialised cells are in the epidermis?

Answer 3

Melanocytes:
Basal layer.
Produce + secrete melanin using tyrosinase gene.
UV protection.
Langerhans cells:
Monocyte lineage.
Immune surveillance.
Merkel cells:
Epithelial lineage.
Mechanoreceptors for touch sensation.

Question 4

What is the main component of the self-regenerating stratified squamous epithelial cells?

Answer 4

Keratinocytes.

Question 5

What are the components of the hypodermis?

Answer 5

Areolar tissue:
Flexible (loose) and strong connective tissue.
Mostly adipose tissue:
(Subcutaneous fat for insulation + energy storage).

Question 6

Why is the hypodermis the target of subcutaneous injections?

Answer 6

High vascularity, absorbs drugs quicker.