Integument II

Question 1

Describe Sebaceous Glands

Answer 1

• Holocrine glands
• Branched acinar glands with short ducts
• Found everywhere except palms and soles
• Continuously produce sebum
  * Released into hair follicle
• Growth is stimulated at puberty by sex hormones

Question 2

Describe merocrine glands

Answer 2

• Coiled, simple tubular secretory portions:
  * Lined by simple epithelium
  * Apical dark secretory cells secrete glycoproteins
  * Basal clear cells secrete water and electrolytes
  * Myoepithelial cells
• Duct system consists of stratified cuboidal epithelium except in epidermis.
• Cholinergic endings

Question 3

What are the two types of sudoriferous glands?

Answer 3

merocrine and apocrine

Question 4

Describe apocrine glands

Answer 4

• Found in labia majora, areola, and axillary and anal regions.
• Secretions are thicker and more viscous than merocrine types.
• Excretory duct opens into hair follicle.
• Adrenergic innervation
• Inactive until puberty
• Special types:
  
  • Ceruminous glands
  • Glands of Moll

Question 5

List the components of a hair follicle.

Answer 5

• Root
• Free shaft
• Hair follicle

Question 6

What is a hair follicle developed from?

Answer 6

epidermis as elastic, keratinized threads

Question 7

What are associated with hair follicles?

Answer 7

Sebaceous glands and arrector pili muscles

Question 8

Describe a hair bulb.

Answer 8

• Expanded lower part of hair follicle
• Matrix
• Vascularized dermal papilla

Question 9

List and describe the two sheaths of a hair follicle.

Answer 9

• External root sheath:
  
  • Down growth of epidermis
• Internal root sheath:
  
  • Generated by bulb matrix
  • Layers:
    * Henle’s layer (outermost)
    * Huxley’s layer
    * Cuticle
    * Interlocks with cuticle of hair shaft

Question 10

List the layers of the hair shaft.

Answer 10

• Medulla (innermost)
• Cortex
• Cuticle

Question 11

What cells can reestablish epidermis in severely burned

patients.

Answer 11

Keratinocyte Stem Cells

Question 12

List the migration pathways of keratinocyte stem cells.

Answer 12

• Bulb-epidermis stem cell pathway
• Bulb-sebaceous gland stem cell pathway
• Bulb-hair stem cell pathway

Question 13

List the signalling pathways of keratinocyte stem cells.

Answer 13

• Wnt signaling pathway

* Notch signaling pathway

Question 14

You treat a cancer patient with chemotherapy. Which layer of the skin will most likely be affected by the chemotherapy treatment?

Answer 14

stratum basale

Question 15

You examine a slide of skin taken from the palm of a cadaver. You notice that there is an extra layer of skin between the stratum corneum and granulosum. What is this extra layer?

Answer 15

stratum lucidum

Question 16

You encounter a patient in the ER who has suffered a second degree burn. What type of cells in the skin will regenerate the epidermis?

Answer 16

Keratinocyte stem cells.