Skin Anatomy

Question 1

What are the 5 functions of the skin?

Answer 1

• Protection
• Thermoregulation
• Excretion of sweat
• Vitamin D synthesis
• Sensory reception

Question 2

What are the 3 layers of the skin?

Answer 2

• Epidermis (of ectoderm origin)
• Dermis (of mesoderm origin)
• Hypodermis (subcut tissue or superficial fascia - connective tissue)

Question 3

What epithelium is the epidermis composed of?

Answer 3

• Stratified squamous keratinised epithelium

Question 4

What are the 5 layers of keratinocytes?

Answer 4

• Stratum basale/germinativum (stem cell)
• Stratum spinosum (prickle cell)
• Stratum granulosum (Keratohyalin granules)
• Stratum lucidum (thick skin)
• Stratum corneum (Cornified layer)

Question 5

What is 1 in every 10 keratinocyte cells?

Answer 5

Melanocyte - pigment producing cell

Question 6

Label the cells of the skin

Answer 6

Question 7

Where are the langerhans cells and what do they do?

Answer 7

• Found in the stratum spinosum layer
• Antigen presenting cells for T cells

Question 8

What are the 2 layers of the dermis?

Answer 8

• Papillary layer - loose connective tissue
• Reticular layer - dense irregular connective tissue

Question 9

How is the papillary layer of the dermis attached to the epithelium?

Answer 9

• Dermal papillae that interdigitate with epidermal (rete) ridges

Question 10

How does epidermis get its blood supply?

Answer 10

• Epidermis doesnt have it’s own blood supply
• relies on diffusion from dermis

Question 11

What makes up your fingerprint?

Answer 11

The papillae in the dermis going up and down

Question 12

Label the layers of the skin

Answer 12

Question 13

What is the hypodermis made up of?

Answer 13

• Primarily adipose tissue segregated by loost connective tissue

Question 14

What does the hypodermis attach?

Answer 14

• Attaches the skin to underlying structures and allow its free movement

Question 15

What is the function of hypodermis?

Answer 15

Insulates the body and provides energy storage

Question 16

Does the hypodermis contain a blood supply?

Answer 16

Yes:
Contains major vessels, nerves, some nerve endings and terminal parts of the skin appendages

Question 17

What are 3 skin appendages?

Answer 17

• Hair and follicles
• Glands (sweat and sebaceous)
• Nails

Question 18

Define:
1. Hair follicle
2. Hair bulb
3. Hair

Answer 18

1. HF is a downgrowth of the epidermis (may extend to hypodermis)
2. HB is the terminal dilation of the hair follicle, consits of: matrix cells surrounding a hair (dermal papilla)
3. Keratinized outgrowth of the hair follicle

Question 19

What is the muscle that moves the hair?

Answer 19

Errector pili (goosebumps = contraction to make the hair standup)

Question 20

What is the:
* Frequency
* Structure
* Function
of the
1. Eccrine glands
2. Apocrine glands

Answer 20

1. Abundant
   * Coiled tubular glands, distal secretory part, narrow duct
   * Role in thermoregulation, protection & excretion
2. Limited to the areola, axilla, anal and external genital regions
   * Coiled tubular glands, wider lumen, branched and open into the hair follicles
   * Become functional at puberty, secretion is pheremone

Question 21

1. What are sebaceous glands and where are they found?
2. What do they produce
3. Function?

Answer 21

1. Branched acinar glands located between the hair follicle and arrector pili musle
2. Produces sebum
3. Waterproofing and protection

Question 22

What does blockage or inflammation of sebaceous glands result in?

Answer 22

Acne

Question 23

What are the nails composed of?

Answer 23

• Nail plate - several layers of dead compacted cells
• Nail bed - beneath nail plate - comprises dermis and epidermis
• Many nerves and vessels

Question 24

What are the 2 types of nerve endings?

Answer 24

• Non-encapsulated
• Encapsulated

Question 25

1. Where are non-encapsulated nerve endings found? 2. What do they do?

Answer 25

1. In epidermis between keratinocytes or attached to merkel cells * In the dermis around the hair follicles 2. In merkel cells detect pain, heat, cold, fine and discriminative touch * In the dermis detects hair displacement

Question 26

1. What are the 2 types of encapsulated nerve endings and where are they found, what do they detect?

Answer 26

1. Pacinian corpuscles (hypodermis) detect pressure and vibration 2. Meissner's corpuscles (dermis) detect light touch

Question 27

What do sympathetic motor efferent nerve endings supply?

Answer 27

* Vascular smooth muscle * Arrector pili muscles * Sweat glands

Question 28

What do the sympathetic sensory nerve endings supply?

Answer 28

* Carry sensation to the CNS