Skin and Fascia 3: Additional Structures of the Skin

Question 1

What are nails?

Answer 1

Hard keratinized plates found on the dorsal surface of the digits

Question 2

What is the purpose of fingernails?

Answer 2

Rigid support for finger tip
Helps efficient fine movements

Question 3

What is the structure of the hair follicle?

Answer 3

Hair follicles are tubular invaginations of epidermis
Arrector pili smooth muscle connects the follicle to the superficial part of the dermis

Question 4

What is hair?

Answer 4

Filaments which arise from hair follicles

Question 5

How are the different parts of the hair formed?

Answer 5

Medulla: Formed from irregular cells
Cortex: Formed from keratin
Cuticle: Flat cells + melanin
Outer epithelial sheath is continuous with stratum spinosum

Question 6

What are the arrector pili muscles?

Answer 6

Band of smooth muscle

Question 7

What does contraction of the arrector pili muscle cause?

Answer 7

Causes sebaceous gland to express the secretion out into the hair follicle
Can contract during exposure to cold

Question 8

What is the function of sebaceous glands?

Answer 8

Secrete sebum which prevent dryness

Question 9

Classify sebaceous glands based on its mechanism of secretion

Answer 9

Holocrine gland

Question 10

What is the structure of a sweat gland?

Answer 10

Single long tube with highly coiled end while the body is the secretory part
Lined by cuboidal epithelium

Question 11

What type of gland is a sweat gland?

Answer 11

Typical gland: Merocrine glands, have watery secretion & secrete by exocytosis

Question 12

What are some examples of atypical glands?

Answer 12

Apocrine gland: Their secretions are viscous and contain proteins. Present in axilla, areola, perianal region and glans penis.
Ceruminous gland: Produce wax in ear