Anatomy Chapter 1 Section 5 Integumentary System

What two things make up the integumentary system?

the skin and its accessory structures

What are the 2 accessory structures?

1. hair

2. nails

3. glands

4. muscles

5. nerves

What is the cutaneous membrane?

the skin

What is the largest organ of the body?

the skin

What are 8 functions of the skin?

1. temperature regulation

2. blood storage

3. protection

4. barrier to the external environment

5. excretion and absorption

6. water repellent

7. provides sensory information

8. synthesizes vitamin D

What are the 2 parts of the skin? What are those parts composed of?

1. epidermis - thin layer of stratified squamous epithelium

2. dermis - thicker layer composed of connective tissue

What is not part of the skin and is sometimes called the subcutaneous layer? What two types of tissue is it composed of?

hypodermis, areolar and adipose tissue (loose connective tissue)

Where is thick skin found? Will the epidermis be thicker or thinner? Will there be hair? Are there any sebaceous glands? How many sudoriferous glands are there? How many sensory receptors are there?

• palms of hands and soles of feet

• epidermis will be thicker

• no hair

• no sebaceous glands

• more sudoriferous glands than thin skin

• more densely packed sensory receptors

Where is thin skin found? Will the epidermis be thicker or thinner? Will there be hair? Are there any sebaceous glands? How many sudoriferous glands are there? How many sensory receptors are there?

• everything except palms, palmer surface of the fingers and soles

• epidermis will be thinner

• has hair

• has sebaceous glands

• fewer sudoriferous glands than thick skin

• has sensory receptors, but not as many as thick skin

What is the order in the layers of skin (top —> bottom)? Which layer is only present in thick skin?

• cornuem

• lucidum - only present in thick skin

• granulosum

• spinosum

• basale

What is the layer that is only 1 row of cuboidal or columnar keratinocytes?

stratum basale

What layer undergoes cell divison and contains melaninocytes, langerhans cells, and merkel cells?

stratum basale

What is the layer that has 8-10 layers of keratinocytes?

stratum spinosum

What is the layer that contains melanocytes and langerhans cells?

stratum spinosum

What is the layer that contains 5 layers of keratinocytes?

stratum granulosum

What layer contains lamellar granules and undergoes apoptosis?

stratum granulosum

What layer contains 3-5 layers of keratinocytes and is only found in thick skin?

stratum lucidium

What layer contains 25-30 layers of dead keratinocytes?

stratum cornuem

What layer contains mostly keratin? This is where the most keratinization takes place.

stratum cornuem

What are the 4 principal types of cells that are found in the epidermis? What do they do?

1. Keratinocytes - produce keratin and lamellar granules

2. Melanocytes - found deep in the epidermis and produces melanin

3. Langerhans cells - aids in immunity

4. Merkel cells - sensory neurons for tactile (touch) sensation

What is the process of when cell of the stratum basale are pushed toward the surface as new cells appear? How long does this process typically occur?

keratinization, 4 weeks or 30 days

What is the connective tissue made of?

collagen and elastic fibers

What are the two layers or regions of the dermis?

Papillary region and reticular region

What region of the dermis is the upper 20% of the total dermis, contains capillary loops, which creates epidermal ridges?

papillary region

What region of the dermis is the lower 80% of the total dermis, attaches to the hypodermis, contains the hair follicles, nerves, blood vessels, glands (sebaceous & sudoriferous) & muscles?

reticular region

What are the three main factors that will affect skin color?

1. Hereditary factors

2. Environmental factors

3. Physiological factors

Hair color is determined by _____________?

melanocytes

What is the superficial portion of the hair that is outside of the skin?

shaft

What is the deep portion of hair that is deep into the skin?

root

What surrounds the hair root?

follicle

What is the expanded base of the follicle?

bulb

What is the projection into the hair follicle at the hair bulb

that contains blood vessels?

papillia

What are the sebaceous glands connected to?

the hair follicles

What are the sudoriferous glands connected to?

sweat glands

What are sebaceous glands?

glands that secrete oil or sebum

What are sudoriferous glands? What are the two types?

sweat glands, eccrine and apocrine

Where is eccrine sudoriferous glands located and what is its function?

• forehead, palms, soles

• function in temperature regulation

Where is apocrine sudoriferous glands located?

• axilla (armpits), groin, bearded region

• hair during puberty region

What are two types of modified specialized sudoriferous glands? What do they secrete?

ceruminous glands - secretes cerumen, mammary glands - secretes milk

What are plates of tightly packed, hard, keratinized epidermal cells?

nails

What is the visible portion of the nail (usually pink in color)?

nail plate (body)

What is the portion of the nail that extends past the nail body and digit?

free edge

What is the crescent shaped area of the nail body distal to the nail root?

the lunula

What is the portion of the nail buried within a fold of skin?

nail root

Where is the nail matrix located?

the nail root

What is the a thickened tissue along proximal border of the nail body? What is another name for it?

Cuticle, eponychium

What is deep into the nail body (the nail body lies on this)? What is another name for this?

Nail bed (hyponychium)

What is the difference between epidermal wound healing and deep wound healing?

epidermal wound healing is avascular and healing relatively quickly while deep wound healing goes all the way through the dermis to the stratum basale, this means that new tissue will grow there or if the gap is small, the tissues will grow back together

What are the 4 phases that occur in deep wound healing? In the 1st stage what 4 things accompany this?

1. Inflammation (redness, pain, swelling, and heat)

2. Migratory

3. Proliferative (excessive growth)

4. Maturation

Which layer of the skin are sebaceous glands found?

the reticular region of the dermis

How are sebaceous glands associated with hair follicles and what do they secrete?

they are connected and attached to hair follicles, and they secrete oil

The ducts of apocrine sweat glands open into what?

hair follicles