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Anatomy & Physiology I > Chapter Six > Flashcards

Flashcards in Chapter Six Deck (48):
1

Organ (describe)

Two or more types of tissues grouped
together and performing specialized
functions

2

Integumentary System (describe)

The skin and its accessory structures (hair, nails, glands, sensory receptors)

3

Skin (describe)

Contains 2 layers: epithelial tissue and overlying connective tissue
Outer layer is the epidermis; inner layer is the dermis

4

Skin

Epidermis (describe)

Outer layer
Stratified squamous epithelium
Basement membrane between epidermis and dermis
Protects against water loss, chemicals, mechanical injury, pathogens

5

Skin

Dermis (describe)

Inner layer
Thicker of the 2 layers of the skin
Connective tissue
Contains collagenous & elastic fibers

6

Skin

Subcutaneous layer (hypodermis) (describe)

Beneath dermis; insulating layer
Areolar and adipose connective tissue
Not considered part of the skin
Contains blood vessels that supply skin

7

Keratinization (describe)

Process of hardening, dehydration, and keratin accumulation that occurs in epidermal cells as they migrate outward

8

Keratin (describe):

Tough, fibrous, waterproof protein made and stored in the cells
As cells reach outer surface, become tightly packed, develop desmosomes, form outer layer, stratum corneum
Stratum corneum cells are eventually shed from skin surface

9

Stratum Basale

Deepest layer of the epidermis, nourished by blood vessels in dermis

10

Melanocytes (describe)

Located in the stratum basale produce the dark pigment melanin
Absorbs UV light from sunlight and provides skin color

11

Factors Affecting Skin Color

Hereditary Factors
Environmental Factors
Physiological Factors

12

Dermis (describe)

Inner layer of skin; average of 1-2 mm thick
Contains dermal papillae to bind epidermis to underlying tissues
Connective tissue layer; contains muscle fibers
Nerve cell processes

13

Layers of Dermis

Papillary layer
Reticular layer

14

Layers of Dermis

Papillary Layer (describe)

Superficial layer; thinner of the 2 layers
Areolar connective tissue
Location of dermal papillae

15

Layers of Dermis

Reticular Layer (describe)

Deeper layer; thicker of 2 layers
Dense irregular connective tissue

16

Accessory Structures of the Skin (list)

Hair follicles
Nails
Skin glands (sweat and sebaceous)

17

Nails (describe)

Protective coverings on ends of fingers and toes

18

Parts of Nail (list)

Nail plate
Nail bed
Lunula

19

Nail Plate (describe)

Overlies nail bed

20

Nail Bed (describe)

Surface of skin, under nail plate

21

Lunula (describe)

Most active growing region; pale, half-moon-shaped region at base of nail plate

22

Hair Follicle (describe)

Tube-like depression of epidermal cells from which hair develops

23

Parts of Hair (list)

Hair bulb (dividing cells)
Hair root
Hair shaft (dead, epidermal cells)

24

Skin Glands

Sebaceous Glands

Produce sebum, which consists of fatty material and cellular debris
Sebum keeps hair and skin soft and waterproof
Excess sebum can result in acne
Absent on palms and soles

25

Skin Glands

Sweat Glands

Also called sudoriferous glands
Widespread in skin
Originate in deeper dermis or hypodermis as ball-shaped coils

26

Types of Skin Glands (list)

Eccrine (merocrine) glands
Apocrine sweat glands
Ceruminous glands
Mammary glands

27

Eccrine (Merocrine) Glands (describe)

Numerous, hands, feet, forehead
Respond to elevated body temperature

28

Apocrine Sweat Glands (describe)

Axillary and groin areas
Secrete by exocytosis
Respond to emotions, pain

29

Ceruminous Glands (describe)

Produce ear wax

30

Mammary Glands (describe)

Produce milk

31

Skin (functions)

Protective covering, barrier against harmful substances and microorganisms
Prevents some water loss
Contains sensory receptors
Excretes some wastes
Helps produce Vitamin D
Helps regulate body temperature

32

Regulation of Body Temperature

Important to regulate body temperature; slight shift can disrupt rates of metabolic reactions
Set point is monitored by Hypothalamus
Skin plays key role in homeostatic mechanisms that regulate body temperature

33

Heat Production and Loss (describe)

Heat is a product of cellular metabolism
The most active body cells are major heat producers: Skeletal muscle, cardiac muscle, cells of the liver
When body is too warm, body responds with vasodilation of dermal blood vessels and vasoconstriction of deep blood vessels. Heat can escape through skin.

34

Methods of Heat Loss

Radiation
Conduction
Convection
Evaporation

35

Radiation (describe)

Primary method of heat loss, infrared heat rays escape

36

Conduction (describe)

Heat moves from skin to cooler objects

37

Convection (describe)

Heat loss into circulating air currents

38

Evaporation (describe)

Sweat changes into a gas, carries heat away

39

Body Temperature Regulation

When Body Temperature Rises

Thermoreceptors signal hypothalamus
Vasodilation of dermal blood vessels
Sweat glands are activated

40

Body Temperature Regulation

When Body Temperature Falls

Thermoreceptors signal hypothalamus
Vasoconstriction of dermal blood vessels
Sweat glands are inactive
Muscles contract involuntarily (shivering)

41

Problems in Body Temperature Regulation

Hyperthermia

Abnormally high body temperature
Can occur on hot, humid day, when sweat cannot evaporate
When air temperature is high, radiation is less effective
Body may gain heat from hotter air
Skin becomes dry, person gets weak, dizzy, nauseous, with headache, rapid pulse

42

Problems in Body Temperature Regulation

Hyporthermia

Abnormally low body temperature
Can result from prolonged exposure to cold, or illness
Shivering is involuntary skeletal muscle contraction, caused by hypothalamus
Progresses to confusion, lethargy, loss of reflexes and consciousness
Without treatment, organs shut down

43

Inflammation (describe)

Inflammation is a normal response to injury or stress
Inflammation is body’s attempt to restrict spread of infection
Blood vessels in affected tissues dilate and become more permeable, allowing fluids to leak into the damaged tissues

44

Shallow Cut (describe)

Affects only the epidermis, results in epidermal cells along its margin dividing more rapidly than usual, to fill gap

45

Deep Cut (describe)

Reaching dermis or subcutaneous layer, results in blood vessels breaking; released blood forms a clot

46

Burns

Superficial, partial-thickness (first degree) burn (describe):

Injures only epidermis, as in sunburn; redness, heat, inflammation
Healing takes days-weeks, no scarring

47

Burns

Deep, partial-thickness (second degree) burn (describe):

Destroys epidermis and some dermis, as in burn from hot liquid
May blister, healing varies with severity of burn & stem cell survival
Stem cells in hair follicles and glands can help regenerate skin
Usually recovers completely, no scarring

48

Burns

Full-thickness (third degree) burn (describe):

Destroys epidermis, dermis, accessory structures
Results from prolonged exposure to heat, flames, hot liquids
Some healing from margins
Often requires skin graft, skin substitutes