Integumentary System part 1

Question 1

The integumentary system consists of ______.

Answer 1

…skin and accessory structures

Question 2

Accessory structures

Answer 2

Sweat glands (sudoriferous glands)
Sebaceous glands (oil glands)
Hair
Nails

Question 3

General functions

Answer 3

Protection & Sensation

Question 4

[General functions] Protection

Answer 4

-From external world (injury)
-Infection
-UV radiation
-Dehydration

Question 5

[General functions] Sensation

Answer 5

-Touch
-Thermoregulation
-Metabolic functions (making Vitamin D)

Question 6

Made of 2 main layers, which names are:

Answer 6

Epidermis & Dermis

Question 7

Epidermis (top layer)

Answer 7

-Keratinized stratified squamous epithelium
-Consists of 4 distinct cell types arranged in 4-5 layers

Question 8

Epidermal cell types

Answer 8

-Keratinocytes (structure)
-Melanocytes (pigment)
-Merkel cells (sensation)
-Langerhans’ cells (phagocytes - immune defense)

Question 9

Keratinocytes

Answer 9

-Most numerous epidermal cell
-Produce keratin
-Tightly connected by desmosomes
-Described as squamous in histology

Question 10

Melanocytes

Answer 10

-Synthesize protein pigment melanin
-Found in deepest layer of epidermis (basale)

Question 11

What does melanin do?

Answer 11

Protects DNA in nucleus from being damaged by UV radiation

Question 12

What type of skin has 5 layers and can only be found in the palms, fingertips, and soles of the feet?

Answer 12

Thick skin

Question 13

What type of skin only has 4 layers?

Answer 13

Thin skin

Question 14

What are the 4 layers of skin both thin and thick skin have in common (lowest to highest)?

Answer 14

Stratum…basale, spinosum, granulosum, and corneum.

Question 15

What’s the one layer of skin that thick skin has but thin skin doesn’t?

Answer 15

Stratum lucidum (below stratum corneum)

Question 16

Stratum basale

Answer 16

-Deepest
-Single row of cuboidal cells
-Cells highly mitoic
-AKA stratum germinativum

Question 17

Stratum spinosum

Answer 17

-2nd deepest
-Cells begin flattening & making keratin precursors
-looks prickly because of desmosomes exposed from being flattened

Question 18

Stratum granulosum

Answer 18

-3-5 cell layers thick
-Cells continue to flatten & cells/organelles disintegrate
-Accumulate granules containing keratin precursor

Question 19

[stratum granulosum] What do the granules contain?

Answer 19

A waterproofing agent —> cells die as they move up cuz they can’t get nutrients

Question 20

Stratum Lucidum (only in thick skin!)

Answer 20

-3-5 layers of flat, dead keratinocytes
-no nuclei/organelles
-clear appearance under right kind of microscope

Question 21

Stratum corneum

Answer 21

-outermost stratum
-20-30 cell layers thick
-protects against:
-Mechanical abrasion
-Pathogen entry
-Desiccation (drying out)
-AKA cornified layer

Question 22

2nd layer of skin

Answer 22

Dermis

Question 23

Material of dermis

Answer 23

Strong flexible fibrous connective tissue

Question 24

Two layers of dermis

Answer 24

Papillary (20%) & reticular (80%)

Question 25

[Dermis] Papillary (above)

Answer 25

Forms dermal ridges (fingerprints)

Question 26

[Dermis] Reticular

Answer 26

-deepest layer of dermis
-where most accessory structures are
-composed mostly of collagen (strength)
-main purpose = prevent damage from mechanical intrusion

Question 27

3rd layer of skin (not official)

Answer 27

Subcutaneous/Hypodermis

Question 28

Subcutaneous/hypodermis main purpose