BIO201 Ch 5 Study guide

Which structure is responsible for forming fingerprints?

dermal ridges

Mammary glands and ceruminous glands are modified versions of:

apocrine glands

Which of the following is true of the stratum basale?

All of the above

Which structure of the hair follicle is a sensory nerve that detects if the hair is touched?

root hair plexus

Which of the following is true of the stratum lucidum?

All of the above

Which layer of the skin is made of dense irregular connective tissue that makes up 80% of the dermal thickness?

reticular layer

Which of the following is true of the stratum corneum?

it is composed of dead cells

Which of the following is true of the stratum spinosum?

the cells are connected together with desmosomes

Which layer of the epidermis has the most mitotically active cells because it is closest to the dermal blood supply?

stratum basale

What is the immediate threat to homeostasis due to burns?

dehydration and electrolyte imbalance

Which type of cell found in the epidermis are star shaped cells that patrol the epidermis and activate the immune system?

dendritic cells

What structures make up the integumentary system?

Hair, skin, nails, sweat glands, sebaceous glands

What are the 6 main functions of the skin?

Protection, Body temperature regulation, cutaneous sensations, metabolic functions, blood reservoir, excretion of wastes

What are the 3 main layers of the skin?  How would you describe each layer?

epidermis, dermis, hypodermis

epidermis

(AVASCULAR) superficial region - Consists mostly of keratinized stratified squamous epithelium

dermis

(VASCULAR) underlies epidermis. Mostly consists of fibrous connective tissue

hypodermis (superficial fascia)

Subcutaneous layer deep to the skin. Mostly adipose tissue that absorbs shock and insulates. Anchors skin to underlying structures, mostly muscles

What 4 types of cells can be found in the epidermis? 

Keratinocytes, melanocytes, dendritic cells (Langerhans), tactile (merkel) cells

What are the layers of the epidermis and where do you find each (deep to superficial)?

Stratum germinativum (stratum basale)

Stratum spinosum (prickly layer)

Stratum granulosum

Stratum lucidum

Stratum corneum (horny layer)

Describe the stratum basal layer.

Deepest of all epidermal layers, single row of mitotic stems cells, -% melanocytes

Describe the stratum spinosum.

Several layers thick, contains web-like system of intermediate prekeratin filaments attached to desmosomes. Helps to resist tension and pulling, abundant keratinocytes, melanosomes and dendritic cells

Describe the granular layer.

4-6 cells thick (layer is thin since cells are flattened) Keratinization begins

Describe the stratum lucidum (clear layer)

Only find in thick skin (sole of foot or palm). Consists of thin translucent band of two to three rows of clear, flat, dead keratinocytes

Describe the stratum corneum (horny layer)

20-30 rows of flat anucleated keratinized dead cells

Why are cleavage lines important?

Important to surgeons because incisions parallel to cleavage lines heal more readily

What are cleavage lines?

Many collagen fibers running parallel to skin surface

Functions of the hair

warn of insects on skin, hair on head helps guard against physical trauma, protect from heat loss, and shield skin from sunlight

Pili

(hair) flexible strands of keratin

What are fibroblasts function?

They produce collagen fibers to bridge the gap until regeneration is complete

Describe the components of a hair follicle and their functions.

1. Hair bulb: expanded area at: end of follicle

2. Hair follicle receptor (or root hair plexus): sensory nerve endings that: wrap around bulb

3. Hair matrix: actively dividing area of bulb that: produces hair cells

4. Arrector pili: small band of smooth muscle attached to follicle

Nail matrix

Responsible for nail growth

Eponychium

cuticle

Koilonchya

“spoon nail” abnormal shape of nail, can indicate iron deficiency

Sweat glands (sudoriferous glands)

Eccrine and apocrine sweat glands

Sweat is

99% water (also contains salts, vitamin C, antibodies, dermcidin (microbe-killing peptide), metabolic wastes (lactic acid)

Eccrine gland:

Most common, on palms, soles, and forehead. For thermoregulation

Apocrine glands

Secrete viscous milky or yellowish sweat that contains: fatty substances and proteins

ABCD rule).*

1. A: asymmetry; the two sides of the pigmented area: do not match

2. B: border irregularity; exhibits: indentations

3. C: color; contains: several colors (black, brown, tan, and sometimes red or blue)

4. D: diameter; larger than: 6mm (the size of a pencil eraser

Describe the 3 steps of tissue repair.

1. Inflammation sets stage - clotting occurs

2. Organization restores blood supply - clotting is replace with granulation tissue

   1. Regeneration and fibrosis effect permanent repair scab detaches and fibrous tissue matures