Integumentary System

Question 1

what is the integumentary system composed of?

Answer 1

• skin
• hair
• oil and sweat glands
• nails
• sensory receptors

Question 2

what are the two main parts of the skin?

Answer 2

1. epidermis
   - thinner portion, composed of epithelial tissue
2. dermis
   - thicker portion, composed of dense irregular connective tissue

Question 3

what are the four principles types of cells in the epidermis?

Answer 3

1. keratinocytes - 90% of epidermal cells arranged in four or five layers to produce the protein keratin
2. melanocytes - 8% of the cells and produce the pigment melanin
3. intraepidermal macrophages (langerhans cells) participate in immune responses
4. tactile epithelial cells - detect touch sensations

Question 4

what are the 4 layers of the epidermis?

Answer 4

1. stratum basale - deepest layer
2. stratum spinosum - provides strength and flexibility
3. stratum granulosum - keratinocytes undergo apoptosis here (genetic programmed cell death)
4. stratum corneum - most superficial layer

Question 5

what is the fifth layer of the epidermis?

Answer 5

• stratum lucidum (only found in thick skin and is located between the granulosum and corneum
• palms and soles (thick skin) have this 5th layer

Question 6

what is the dermis mainly composed of?

Answer 6

• connective tissue containing collagen and elastic fibers

Question 7

how is the surface area of the dermis increased?

Answer 7

• small, fingerlike projections called dermal papillae, touch receptors (meissner corpuscles) and free nerve endings

Question 8

what does the deeper part of the dermis consist of?

Answer 8

• dense irregular connective tissue containing bundles of collagen and some coarse elastic fibers
• adipose cells, hair follicles, nerves, oil glands, and sweat glands are found between the fibers

Question 9

what are the accessory structures of the skin?

Answer 9

• hair
• glands
• nails

Question 10

hair (pili) location, structure

Answer 10

• present on most skin surfaces except the palms, palmar surfaces of the fingers, soles, and plantar surfaces
• they are dead, keratinised epidermal cells
• consist of shaft (most superficial), a root (into the dermis) and follicle

Question 11

what determines the colour of hair?

Answer 11

• melanin
• gray hair occurs with a decline in melanin
• white hair results from accumulation of air bubbles in the hair shaft

Question 12

what are glands and which ones associate with the skin?

Answer 12

• single or groups of epithelial cells that secrete a substance
  sebaceous - secrete sebum
  ceruminous - secrete cerumen
  sudoriferous (sweat) glands - secrete sweat
• apocrine
• eccrine

Question 13

what are nails, their principles and where they are located within the skin.

Answer 13

• hard, dead, keratinised epidermal cells covering the terminal portions of the fingers and toes
• principle parts are the nail body, free edge, nail root, lunula, cuticle, nail matrix
• the proximal portion of the epithelium deep into the nail root is called the nail matrix. cell division of the matrix cells produces new nails.

Question 14

what are the functions of the skin?

Answer 14

• body temperature regulation
• protection
• cutaneous sensations
• excretion and absorption
• synthesis of vitamin D

Question 15

what changes in the skin as a person ages?

Answer 15

• collagen fibers in the dermis begin to decrease in number, stiffen, break apart, and disorganise into a shapeless, matted tangle
• elastic fibers lose some of their elasticity, thicken into clumps and fray, an effect that is greatly accelerated in the skin of smokers
• fibroblasts, which produce both collagen and elastic fibers, decrease in number, and as a result, the skin forms crevices known as wrinkles

Question 16

what are some other aging changes?

Answer 16

• decreased gland numbers and production leading to less sebum and less sweat
• hair follicles and melanocytes slow and hair things, becomes grayer and may stop growing at all
• slower skin healing as immune cells decrease, dry skin fails to protect as well, and epidermal cells repair damage slower

Question 17

what are pressure ulcers? what are their symptoms?

Answer 17

• caused by a consistent deficiency of blood flow to skin tissues
• typically underlying bony structures are subjected to constant pressure from a bed, cast, or similar object
• as pressure continues, symptoms range from redness to blistering and ultimately ulceration as deeper tissue is damaged and dies

Question 18

what is an abrasion?

Answer 18

• type of open wound caused by skin rubbing against a rough surface usually affecting the epidermis
• may be called a scrape or a graze
• can range from mild to severe

Question 19

what is an incisional wound?

Answer 19

• made by cutting through skin, muscle, and fat so that a body part can be repaired or removed

Question 20

what is a puncture wound?

Answer 20

• a forceful injury caused by a sharp, pointed object that penetrates the skin
• usually narrower and deeper than a cut or scrape

Question 21

what is a penetrating wound?

Answer 21

• caused by objects penetrating the body
• pierce the skin and lacerate, disrupt, destroy or contuse adjacent tissue creating an open wound
• most common are gunshot wounds and sharp instruments

Question 22

what is a contusion?

Answer 22

• a bruise

Question 23

what is a haematoma?

Answer 23

• collection of blood in or near a recent surgical incision
• typically occurs in the subcutaneous space
• may occur deeper in the incision
• often caused by inadequate haemostasis after the skin has been closed

Question 24

what is a laceration?

Answer 24

• a wound that occurs when skin, tissue and/or muscle is torn or cut open.
• may be deep or shallow, long or short, wide or narrow