Ch 5 Anatomy

Question 1

Three major layers of the skin

Answer 1

Epidermis, Dermis, and Hypodermis

Question 2

What are the functions of the integumentary system?

Answer 2

• Protection: chemical, physical and mechanical
• Temperature regulation
• Cutaneous sensation
• Metabolic functions: Synthesis of vitamin D
• Blood reservoir: holds 5% of blood volume
• Excretion: some nitrogen wastes lost in sweat

Question 3

Keratinocytes

Answer 3

Produce keratin which is the fibrous protein that gives the epidermis its protective properties.

Question 4

Melanocytes

Answer 4

• spider shaped epithelial cells that synthesis the pigment melanin are found in the deepest layer of the epidermis.
• Form a pigment shield that protects the nucleus from the damaging effects of ultraviolet radiation in sunlight.

Question 5

Dendritic cells (Langerhans cells)

Answer 5

• arise from bone marrow and migrate to the epidermis.

- they ingest foreign substances and are key activators of our immune system.

Question 6

Tactile cells (Merkel cells)

Answer 6

• are present at the epidermal-dermal junction.

- function as a sensory receptor for touch.

Question 7

Stratum Basale

Answer 7

• Deepest epidermal layer
• single row of stem cells
• 10 to 25% of cells are melanocytes.

Question 8

Stratum Spinosum

Answer 8

• several layers thick

- contain a weblike system of intermediate filaments, mainly tension- resting bundles of pre-keratin filaments.

Question 9

Stratum Granulosum

Answer 9

• consists of three to five layers of flattened cells

- two types of granules: keratohyaline granules and lamellar granules.

Question 10

Stratum Corneum

Answer 10

• most superficial layer
• 20 to 30 layers of dead cells
• essentially flat membrane sacs filled with keratin
• Glycolipids in extracellular space

Question 11

Describe the dermis

Answer 11

• strong flexible connective tissue

- has two layers: papillary and reticular layer

Question 12

Which pigments contribute to skin color and what color does each add?

Answer 12

-Skin color is determined by the amount of melanin present.

Question 13

Erythema

Answer 13

Reddened skin may indicate embarrassment(blushing), fever, hypertension, inflammation, or allergy.

Question 14

Pallor, or blanching

Answer 14

• During fear, anger, and certain other types of emotional stress, some people become pale.
• Pale skin may also signify anemia or low blood pressure.

Question 15

Jaundice or yellow cast

Answer 15

an abnormal yellow skin tone usually signifies liver disorder, in which yellow bile pigments accumulate in the blood and are deposited in body tissues.

Question 16

Bronzing

Answer 16

A bronze, almost metallic appearance of the skin is a sign of Addisons disease, in which the adrenal cortex produces inadequate amounts of its steroid hormones; or a sign of pituitary gland tumors that secrete melanocyte-stimulating hormone.

Question 17

Black-and-blue marks or bruises

Answer 17

blood has escaped from the circulation and clotted beneath the skin. These are called hematomas.