chapter 5 integumentary system

what is function of sebum?

a waxy oily mixture, mixed with cell junk.

describe the layers and basic structure and components of the dermis

papillary layer- thinner of the two superficial layers : composed of loose connective tissue. reticular layer- deep thick layer that seperates dermis form hypodermis. composed of dense irregular tissue.

how is melanin produced and its role in the integument?

melanin helps protect the karitonocytes from harmful u.v. rays. helps keep the keratinocytes from mutating. it is made by the determining of orange-red to black protein pigment melanin.

describe sebacious glands

oil glands, with bulb like structures( acni), they release product through duct, use hair follicle to create sebum.

describe how thick and thin skin differ

thick - has all five layers subject to areas with alot of mechanical stress. thin- in areas with little mechanical stress: has 4 layers, more hair.

describe the 4 types of sweat or sudoriferous glands-

1. Eccrine Glands- coiled tube that exits straight onto the apical surface. makes watery sweat. 2.Appocrine sweat glands- become active after puberty; coiled tube that borrows hair follicle to exit. makes a protein rich sweat, can be oderiferous. 3. ceruminous gland- produces earwax into ear; modified aprocrine gland. 4. mammary glands- modified sweat gland, that produces milk.

describe 4 types of cells located in epidermis

1. Keritinocytes- make keratin 2. dendritic cells- protect skin and deeper tissue from pathogens.( immune system) 3. merkel cells- detect light, discriminate shapes and texture, specialized for touch. 4. melanocytes- produce melanin, protect skin.

describe the 5 layers of epidermis

1. Stratum basale- single layer of cells on bottom; has keratinocytes, merkel cells, melano cytes, stem cells, 2. stratum spinosum-thickest layer, close to blood supply, stratum granulosum- has cytoplasmic granulosum, where we make water proofing for skin. 3. stratum lucidium- clear dead keratinocytes, found only in thick skin. 4. stratum corneum- outermost layer of epidermis, dead flattened keratinocytes; mostly keratin bundles. shed these.(slough off)

distinguish between the three types of hair

1. lanugo- thin nonpigmented hair; generally fall out around birth. 2. terminal hair- thick, coarse pigmented hair. surrounding eyes, on scalp. 3. vellus hair- thinner nonpigmented hair.

explain the functions of the dermal papillae, tactile corpuscles, lamellated corpuscles, dermal ridges, and epidermal ridges

1.dermal papillae- tiny projections found at surface; help give blood and other to avascular epidermis. 2. tactile corpuscles- sensory receptors to light and touch, give deeper sensation than merkel cells. 3.lamellated corpuscles- in reticular layer; more vibration and pressure. 4. dermal ridges- found where dermal papillae are more prominent. presence of thick collagen bundles. 5.epidermal ridges- enhance gripping ability of hands and feet. ( loops, arches)

briefly describe the minor pigments that contribute to skin color

carotene- yellow- orange pigment accumulates in stratum corneum. hemoglobin- foud in red blood cells, helps body carry oxygen.

describe the basic structure of skin

epidermis- avascular layer(keratinized stratified) dermis- deep to epidermis; loose connective tissueand dense irregular. cutaneous membrane- sweat glands, sebacious glands, hair and nails. arrector pilli muscle- muscle with hair. hypodermis- deep to dermis: fat layer

describe the basic functions carried out by the components of the integumentary system

sensation- percieve changes in body or external of body. Thermoregulation- regulate heat through negative feedback Excretion- where process and toxins are rid of the body