Skin LO6

Question 1

Skin

Answer 1

Composed of epithelial tissue, connective tissue, muscle tissues and nervous tissue
3 main regions
- epidermis – outer epithelial layer
- dermis – deep supporting layer of connective tissue
- hypodermis – subcutaneous layer of
connective tissue and adipose tissue

Question 2

Epidermis

Answer 2

• avascular: oxygen and nutrients diffuse from blood vessels of the dermis
• cells of the epidermis are tightly joined together to create continuous sheets
  of cells: prevent substances moving through spaces
• epidermis is constantly being renewed
• dead cells are replaced with new cells
• cells move from the deepest layer of the epidermis to a more superficial layer, they flatten, and eventually die.

Question 3

Dermis

Answer 3

consists of connective tissue
* cells: macrophages and fibroblasts
* fibroblasts produce collagen & elastic fibers: provide tensile strength & flexibility
contains
* blood vessels
* nerves & sensory receptors
* glands
* sweat: produce sweat
* sebaceous: produce sebum
* hair follicles

Question 4

Hypodermis

Answer 4

consists mostly of adipose tissue
functions:
* anchors skin to underlying tissue
* stores fat
* shock absorber
* insulaton

Question 5

Functions of the skin

Answer 5

1. Sensations (Blood flow, pain, temp, touch etc)
2. Metabolic functions (vitamin d)
3. Excretion (wastes excreted through sweat)
4. Protection (physical/mechanical barriers - block things entering, chemical barriers - pH, biological barriers - macrophages)
5. Blood reservoir
6. Temperature regulation

Question 6

cutaneous membrane

Answer 6

skin, exposed to the air and is dry

Question 7

mucous membrane

Answer 7

lines the bodies cavities that are open to outside of body. Found in digestive, respiratory, urinary and reproductive tracts.
Wet membranes

Question 8

serous membrane

Answer 8

line closed ventral body cavities.
Secretes a clear serous fluid to lubricate surface. Wet
membranes that are not exposed to external
environment