Chapter 5 Part 2 Flashcards
1
Q
Hair
A
- Hair itself (also called pili) are flexible strands of dead keratinized cells. Contains hard keratin, not soft keratin like in skin. Hard keratin is durable and the cells won’t flake off. Made in Hair Follicles
- Located everywhere except palms, soles (of feet), lips, nipples, and portions of the external genitalia.
- Functions) Warn of objects on the skin, Guard against trauma (in thick areas), Protect from heat loss and to shield the skin from sunlight.
2
Q
Regions of the Hair
A
- Shaft) Area of hair where keratinization is complete. Area that extends above the scalp.
- Root) Area within the scalp where keratinization is still going on.
3
Q
Shapes of Hair
A
- If the hair shaft is Flat and Ribbon like the cross section the hair will be Kinky.
- If shaft is oval in the cross section the hair will be wav
- If the shaft is perfectly round the hair will be straight.
4
Q
Three Parts of the Hair Shaft
A
- Medulla) Central core of large cells and air spaces and the only part of the hair which has Soft Keratin. It is absent in fine hairs.
- Cortex) Several layers of flattened cells surrounding the medulla.
- Cuticle) Outer layer consisting of overlapping layers (shingles on roof). Heavily keratinized; provides strength and keeps inner layer compact.
5
Q
Hair Color
A
- Pigments are made by melanocytes in the hair follicle.
- Combinations of the different colors of melanin (yellow, rust, brown, black) create the hair colors.
- Red hair also has the Pheomelanin pigment. Grey/white hair results when melanin production slows and air bubbles replace melanin in the hair.
6
Q
Hair Follicle
A
- (Folli - Bag) Folds down from the epidermal surface into the dermis. Extends from the epidermal surface into the dermis.
- Hair Bulb) Expanded area at the deep end of follicle.
- Hair Follicle Receptor (Root Plexus) sensory nerve endings that wrap around the hair bulb.
- Hair is considered a sensory touch receptor.
7
Q
Components of the Hair Follicle Wall.
A
- Peripheral Connective Tissue Sheath) Fibrous sheath derived from the dermis.
- Glassy membrane) thickened basil lamina
- Epithelial Root Sheath) derived from the epidermis.
8
Q
Hair matrix
A
- Area of bulb which actively dividing and making cells.
- As the matrix makes new cells it pushes the older ones upward.
9
Q
Arrector Pili
A
Small band of smooth muscle attached to the hair follicle. Responsible for goosebumps.
10
Q
Hair Papilla
A
-Dermal tissue containing a knot of capillaries that supply nutrients to growing hair. 1
11
Q
Nail Properties
A
- Scale like modifications of epidermis that contain hard keratin; protect the distal, dorsal surface of fingers and toes.
- Consist of a free edge, nail plate/body, and root.
- Nail bed is epidermis under the nail.
- Nails appear pink because of
12
Q
Nail Matrix
A
-Thickened portion of bed responsible for nail growth.
13
Q
Nail Folds
A
-Skin folds that overlap border of the nail
14
Q
Eponychium
A
- Also known as a cuticle.
- Is a nail fold that projects onto the surface of the nail body.
15
Q
Hyponychium
A
-Area under free edge of nail that accumulates dirt,
16
Q
Lunula
A
-Thickened nail matrix, appears white.
17
Q
Sweat Glands
A
- Also called sudoriferous gland (Sudor=sweat)
- Located on all skin surfaces except for nipples and some parts of the external genitalia
- Contain myoepithelial cells which contract sweat glands.
18
Q
Eccrine Sweat Glands
A
- Most abundant type. Located on palms, soles, and the forehead (places with no hair). Releases sweat via exocytosis (merocrine gland)
- Each is a Simple, Coiled, Tubular gland which connects to a pore on the skin.
- Function in thermoregulation by secreting sweat. the sweat is 99% water, salts, vitamin c, antibodies, metabolic waste, and Dermcidin (microbe- killing peptide).
- Ph is between 4 and 6
19
Q
Apocrine Sweat Glands.
A
- Confined to Axillary/ Anogenital areas. Large glands with ducts that empty into hair follicles.
- Vicious, Milky/Yellow sweat that contains fatty acids and proteins. Bacteria breaks down in this sweat which leads to body odor.
- Begin functioning at puberty. May be some form of sexual pheromone but does little in the way of thermoregulation.
20
Q
Modified Apocrine Sweat Glands
A
Ceruminous Glands) Lining of external ears. They secrete cerumen (earwax)
Mammary Glands) Secrete Milk.
21
Q
Sebaceous Glands
A
- Simple branched alveolar glands that produce sebum (oil)
- Found everywhere except thick skin and the palms/ soles. Most develop/ secrete directly in hair follicles. Relatively inactive until puberty.
- Produce sebum, an oily secretion, via holocrine excretion. Sebum softens hair and skin.
22
Q
Acne
A
- Active inflammation of the sebaceous glands.
- Accompanied by pimples.
23
Q
6 Functions of the Integumentary System
A
1) Protection
2) Body Temperature Regulation
3) Cutaneous Sensations
4) Metabolic Functions
5) Blood Reservoir
6) Excretion of Wastes.
24
Q
Protection (Function)
A
- The skin is exposed to many microorganisms, abrasions, extreme temperatures, and chemicals.
- To protect against these factors the skin creates three barriers called the chemical, physical, and biological barrier.
25
Chemical Barrier
- Skin secrets chemicals to protect itself such as Sweat (antimicrobial proteins), Sebum and Defensins (kill bacteria) and cell defensins.
- Acid Mantle) skin has a pH of 4-6 which protects against bacterial multiplication.
- Melanin) protects agains UV rays.
26
Physical Barrier
-Rows of Flat, Dead, Keratinized cells in the stratum corneum. They are surrounded by glycolipids which block most water and water soluble substances.
27
Biological Barriers
- Epidermis) has phagocytic cells such as dendritic cells (engulf cells and bring them to white blood cells)
- Dermis) Contains Macrophages (also bring foreign cells to white blood cells)
- DNA can also absorb some UV radiation.
28
Body Temperature Regulation (Thermoregulation)
- Normal Heat) body will sweat about 500ml/day which is noticeable. This is called Insensible perspiration
- High Heat) Body will dilate dermal vessels and increase sweat gland production to 12L (3gallon) per day to cool body. Called Sensible Perspiration
- Cold Temp) Body will constrict dermal vessels and drop skin temperature.
29
Cutaneous sensations (Function)
- Cutaneous sensory receptors are part of the nervous system.
- Exteroreceptors) respond to stimuli outside body such as temp or touch.
- Free Nerve endings) sense painful stimuli
30
Metabolic Functions (of Integumentary System)
A) Synthesis of Vitamin D. (Needed for calcium absorption in digestion)
B) Epidermis makes chemical conversion. (Some form of synthesis occurring in epidermis)
31
Blood Reservoir (Function)
-The skin can hold up to 5% of the body's blood. This is done when other systems temporarily shut down (fight or flight)
32
Excretion
-Skin can excrete small amounts of waste (nitrogenous waste, ammonia, urea, uric acid) in the sweat.
33
Skin Cancer.
- Skin can have a number of different ailments. Skin Cancer is a very damaging ailment.
- Most skin cancer tumors are benign but will not metastasize (spread).
- Risk Factors) Overexposure to UV radiation and Frequent Irritation of the skin.
34
Basal Cell Carcinoma
- Least Malignant and most common skin cancer. Occurs when basal cells proliferate and invade dermis and hypodermis.
- Cured by surgical extraction in 99% of cases
35
Squamous Cell Carcinoma
- Second most common type of cancer. Can Metastasize to other cells. Found in keratinocytes of stratum spinosum
- Appears as red, scaly papule appearing on the scalp, ears, lower lip, or hands.
- If found early and removed via surgery or radiation therapy the chance of complete cure is good.
36
Melanoma
- Cancer of Melanocytes. Very dangerous as it is resistant to chemotherapy and highly metastatic.
- Treated via extraction accompanied with immunotherapy. The best chance of survival is early detection.
37
Burns
- Tissue damage caused by heat, electricity, radiation, and certain chemicals. Denatures proteins which destroys body cells.
- Immediate threat to survival is dehydration and electrolyte imbalance.
- To evaluate burns the Rule of Nines is used. It is used to estimate volume of fluid loss.
38
First Degree Burns
- Epithelial Damage only. Local redness, swelling, and pain.
- Referred to as partial thickness.
39
Second Degree Burns
- Epidermal and upper dermal damage. Blisters will appear.
| - Partial thickness burn because only epidermis and dermis are involved.
40
Third Degree Burns
- Entire thickness of skin is burned. Referred to as full thickness because it burns down to hypodermis.
- Skin turns grey white or cherry red and blacked. There is no pain as the nerve endings of the skin gets destroyed.
41
Severity/ Treatment of Burns.
- Burns are considered critical if 1) 25% of the body has second degree burns 2) 10% of the body has third degree burns 3) face, hands, or feet have third degree burns.
- Treatment includes debridement (removal of burnt skin) antibiotics, temporary covering, and skin grafts.
