Integumentary System

Question 1

Epidermis

Answer 1

• Most superficial layer of skin; entirely epithelial cells

- Does NOT contain blood vessels

Question 2

Function: Protection, Secretion, & communication

Answer 2

o Protects against bacteria, viruses, & various chemicals from entering the body.
o Sweat glands help rid the body of metabolic wastes.
o Sensory receptors: send information to the brain regarding pain, touch, pressure, & temperature.

▪ Protection, secretion, & communication. Skin
manufactures vitamin D & absorbs certain chemicals
(meds).

Question 3

Layers of the skin

Answer 3

o Stratum Corneum: “Top Layer”- Dead keratinocytes. composed of approximately 20 layers of flat cell-remnants that are like “bags of turtle wax”

o Stratum Lucidum: “Clear Layer”- Colorless protein eleidin

o Stratum Granulosum: “Thin Layer”- granular layer

o Stratum Spinosum: “Spiny Layer”- Thickest layer, keratinocytes, immune dendritic cells, sensory cells. 8–10 keratinocytes

o Stratum Basale: or stratum germinativum “Basal Layer”- Bottom layer; contains melanocytes

Question 4

Dermis

Answer 4

Directly below epidermis; mostly connective tissue

• Contains blood vessels
• Sensory receptors
• Hair follicles
• Sebaceous glands
• Sweat glands
• Elastin and Collagen fibers

Question 5

Hypodermis/SubQ

Answer 5

Connective tissue

• Binds the skin to underlying muscle
• Fat deposits cushion and insulate the body

Question 6

Glands

Answer 6

Exocrine: Secrete substances into ducts
Holocrine: secretory products; whole cells; connected to hair follicle
o Sebaceous Glands: secrete sebum: an oily mixture of lipids and proteins; waterproofs skin, protects from pathogens
Eccrine: Not connected to hair follicle, activated by high body temperature, located throughout
the body. A type of sweat gland (sudoriferous gland) in thermoregulation.
o Secrete a salty solution of electrolytes and water
-NaCl
-KHCO3
-Glucose
-Antimicrobial Peptides
Apocrine: Secrete an oily solution (fatty acids, triglycerides, and proteins)
o Located in:
- Armpits
- Groin
- Palms
-Soles of feet
o Secrete (sweat) during anxiety or stress
o Body Odor forms from bacteria feeding on apocrine sweat

Question 7

Skin’s involvement in temperature homeostasis

Answer 7

➢ Sweat glands to cool off body. Vasodilation of blood vessels.
➢ Shivering heats the body.
➢ Sebaceous & sweat glands are exocrine. Secret through ducts.
➢ Sebaceous are holocrine glands, and secrete sebum.
o Inhibits water loss from the skin, protects against bacterial & fungal infections.
➢ Sweat glands are either eccrine or apocrine glands. Apocrine are located in the armpits, groin, palms, & soles of the feet.