1. Chapter 6
Integumentary System

2. Skin Picture p.118 & p.123

3. The Integumentary System
Membranes of epithelium and connective tissues that cover body surfaces and lines cavities and organs.
2 or more tissues grouped together = organs
4 Membranes:
Serous
Mucous
Synovial
Cutaneous (skin)
Skin Video

4. Types of Membranes SEROUS
Lines body cavities that lack openings to the outside
Thorax - Parietal pleura/Visceral pleura
Abdomen – Parietal peritoneum/Visceral peritoneum
Contains simple squamous epithelial and loose connective tissue
Cells secrete serous fluid to lubricate

6. Types of Membranes MUCOUS Lines cavities that open to outside of body
Oral & nasal cavities, digestive, respiratory, urinary, reproductive
Contains epithelium and loose connective tissue
Mucous cells secrete mucus

7. Types of Membranes SYNOVIAL
Inner linings of joint cavities, between ends of bones, and freely movable joints
Knees, shoulder, phalanges
Contains loose connective tissue & adipose tissue
Synovial cells secrete a thick, colorless
synovial fluid that lubricate the ends of bones.

8. Adipose (fat) Beneath skin
NAME
LOCATION
EXTRAS
Adipose
(fat)
Beneath skin
Insulates & cushions, stores energy…average adult has billion fat cells

9. CUTANEOUS (SKIN) Largest (by weight) and very versatile organ
Vital in maintaining homeostasis:
Regulates body temperature
Limits water loss
Houses sensory receptors
Synthesizes various biochemicals
Excretes wastes
2.5 Layers
Epidermis
Dermis
Subcutaneous (not a true layer of skin because it’s beneath the skin!)
Basement membrane separates these layers

11. EPIDERMIS
Outer layer of stratified squamous epithelial tissue and lacks blood vessels
Keratinization: older cells harden, cytoplasm fills with strands of tough, fibrous, keratin-waterproof protein (stratum corneum)
Stratum corneum
-avascular (lacks blood vessels) old, hard, dead cells
Stratum basale
- gets blood supply from dermis-cells grow and divide and move/pushed up

12. Stratified squamous
Layers of thin cells that reproduce deep within and push old cells outward.
Keratinization – process which a
protein accumulates as skin ages…causes cells to harden and die

13. Epithelial Tissue
Covers all body surfaces, lines internal organs/body cavities and gland tissues
No blood vessels, but are nourished thru diffusion from underlying connective tissues
Reproduce quickly (heals quickly)
Functions: secretion, absorption, excretion, sensory receptors

15. EPIDERMIS The growth and loss of cells is balanced
Cell reproduction increases where skin is rubbed or pressed regularly, causing thickened areas called calluses.
Functions (protective)
Shields underlying tissues from water loss
Mechanical injury
Harmful chemicals
Keeps out disease

16. EPIDERMIS Contains melanocytes (cells) that produce melanin
Absorbs light energy to protect deeper cells from the sun’s ultraviolet rays.
Produces skin/hair color
Amount of melanin produced and size of granules determines how light/dark your skin is, as well as genetics, sunlight, blood in surface vessels (high O2 = pink & low O2 = blue –cyanosis)
All people have the same number of melanocytes…differences occur in melanin amount and size!

18. DERMIS
Inner layer that contains fibrous connective tissue, epithelial, smooth, nervous, and blood tissues
Thicker
Tough & elastic (due to collagen & elastic fibers)
Contains blood vessels
Give nutrients to all skin cells and regulates body temp (if hot blood vessels expand to release heat, if cold blood vesslesl contsrict to keep heat in)
Bed sores
Contains nerve fibers, hair follicles, sebaceous glands, and sweat glands

19. Subcutaneous (hypodermis)
Beneath dermis/continuous from
Contains loose connective and adipose tissue
Insulates
Binds skin to underlying organs

20. Accessory Organs 1) Hair follicles
Hair is found everywhere except palms, soles, lips, nipples, and external reproductive organs
Hair is dead epidermal cells (keratinized)
Arrector pili muscle
attached to hair follicle
Contracts in cold or upset (goosebumps)
Color from melanin
More = darker
Less = lighter
None = albinism/old age
Trichosiderin = red
shaft
Hair follicle
Cell division occurs here

22. Congential generalized hypertrichosis-”werewolves”

23. Accessory Organs 2) Sebaceous Glands (holocrine glands)
Attached to hair follicles
Secrete oily mixture of fat and cell debris called sebum
Keeps hair and skin soft, pliable and waterproof
* Acne: overactive and inflamed sebaceous gland that becomes plugged and surrounded by small, red elevations (pimples/blackheads)

24. Accessory Organs 3) Nails
Protective coverings over the ends of fingers and toes.
consist of stratified squamous epithelial cells overlying the nail bed, with the lunula as the most actively growing region of the nail root.
As new cells are produced, older ones are pushed outward and become keratinized.

26. Accessory Organs 4) Sweat Glands (sudoriferous glands)
Sweat = water, salt, waste (urea & uric acid)
Apocrine gland (emotional – pain, nervous, upset, frightened)
armpit and groin
Exocrine gland (hair follicles)
palms and soles of feet
Eccrine gland (heat and exercise)
most abundant
forehead, neck, back

27. Sweat Glands

28. 4 Major Types of Tissues (pg. 95)
Epithelial
covering
Connective
support
Muscle
movement
Nervous
control

30. Body Temperature Regulation
Increased temp – Nervous system signals blood vessels to dilate (open), sweat glands to secrete, heat is lost…sweat evaporates cooling the skin
Decreased temp – Nervous system signals blood vessels to constrict (smaller), sweat glands become inactive, heat is retained…muscles contract involuntarily to generate heat
Normal 98.6˚F/ 37˚C
Hypothermia below 95˚F
Hyperthermia above 106˚F

31. Videos
Integumentary System Part 1 Integumentary System Part 2