Anatomy & Physiology I Ch. 5 (Integumentary System)

Front 1

Organ

Back 1

group of tissues that performs a specific funtion

Front 2

Integumentary system

Back 2

skin and its derivatives

Front 3

Skin

Back 3

an organ made of different tissues joined together to perform a specific function

Front 4

Dermatology

Back 4

the medical specialty that deals with skin disorders

Front 5

Structures

Back 5

part of the integument
-skin, hair, nails, glands

Front 6

Overview of Functions

Back 6

Protection, sensation, temp. regulation, vitamin D production, excretion, immunity

Front 7

3 Layers of skin

Back 7

- Epidermis (stratified squamous)
- Dermis (dens irregular)
- Hypodermis (not part of skin)
- Subcutaneous

Front 8

Epidermis

Back 8

- Composed of cells arranged into layers or strata
- Seperated from dermis by basement membrane
- Avascular, nourished by diffusion from capillaries of the papillary layer of dermis

Front 9

Epidermal Cells

Back 9

- Cell types
-Keratinocytes, Melanocytes, langerhaun's cells, merkel's cells
- Desquamate - shluffing off of dead skin cells
- Keratinization - process where carotine is added to cells & waterproofs skin

Front 10

Melanocytes

Back 10

contribute to skin color, everyone has the same amount

Front 11

Langerhan Cells

Back 11

Has an immune function

Front 12

Merkel Cells

Back 12

senses light touching

Front 13

Thin Epidermis - 1-3 mm

Back 13

- More flexible than thick skin

- Covers rest of body

- Hair grows here

Front 14

Thick Epidermis - 4-5 mm

Back 14

- Has all 5 epithelial strata

- Areas under pressure or friction

- Fingerprints & footprints. Papillae or underlying dermis in parallel rows

Front 15

Callus

Back 15

- Increase in # of layers in stratum corneum

- When this occurs over boney area, corn forms

Front 16

Skin color - Factors influencing Pigmentation

Back 16

- Heredity, sunlight exposure, hormone secretion by anterior pituitary, age, blood volume, amount of unoxygenated hemoglobin, thickness of corneum (thicker areas can be yellowish)

Front 17

Adrenocorticotropic Hormone (ACTH)

Back 17

Peptide structure of the Adrenal cortex, Increases glucocorticoid hormone secretion

Front 18

Melanocyte-stimulating Hormone (MSH)

Back 18

Peptide structure of the Melanocytes in the skin, Increases melanin production in melanocytes to make the skin darker in color

Front 19

Tyrosinase

Back 19

Enzyme that converts the amino acid tyrosine to dopaquinone.

Front 20

Melanocytes

Back 20

Irregularly shaped cells that extend into the stratum basale and stratum spinosum. Produces Melanin

Front 21

Dermis "True skin"

Back 21

- Contains nerves, blood vessels, hair follicles, smooth muscles, skeletal muscles, glands, & lymphatic muscles
- Sensory functions
--Pain, itch, tickle, temperature, touch, pressure, two-point disscrimination

Front 22

2 Layers of Dermis

Back 22

Papillary layer (fingerprints)

Reticular layer (leather)

Front 23

Accessory skin structures: Hair

Back 23

- Shaft protrudes above skin surface (visible portion)

- Root is below surface; base of root = hair bulb

- 3 Centric Layers

Front 24

Hair: 3 centric layers

Back 24

Medulla - central axis

Cortex - Bulk of hair; layers of keratinized cells

Cuticle - Forms hair surface

Front 25

How hair grows - Follicle forms, germinal matrix forms, formation of hair papilla

Back 25

- Follicle - a small tube is formed as the cells of the epidermis spread into the dermis

- Germinal matrix - a cube-shaped cluster of cells which forms at the bottom of the follicle from the stratum germinativum; these are responsible for forming hairs

- Hair papilla - a small round mound of dermis that protrudes into the germinal matrix; it contains capillaries that nourish the germinal matrix

- Skin glands - inside dermis

--Sebaceous glands
□ Secretes sebum (oil); has antifungal effect
□ Prevents drying & may inhabit bacteria
□ Most empty into hair follicle

Sweat gland - two types traditionally called apocrine & merocrine, but apocrine may secrete in a merocrine or holocrin fashion

Front 26

Dermis - Merocrine (aka Eccrine)

Back 26

- Open directly onto surface or skin

- Functions throughout life

- Numerous in palms & soles of feet, can be as numerous as 3000/sq in. in the palms. Absent from margin of lips, labia minora, tips of penis, and clitoris

Front 27

Dermis - Apocrine

Active at puberty hypodermis

Back 27

- Open into hair follicles superficial to opening of sebaceous gland

- Secretion: organic compounds that are odorless but, when acted upon by bacteria, may become odiferous

- Found in axillae, genitalia, around anus

Front 28

Misc notes

Back 28

- 5 sizes of sovatious glands declines

- Production of sweat deminishes with age

- Old people are more susceptible to heat stroke

- Decline in number of malenocytes

- Age of integumentary system

Lunula - most active