HAP1 - Exercise 7

Ace your homework & exams now with Quizwiz!

Follicle

- a structure formed from both epidermal and dermal cells. Its inner epithelial root sheath with two parts (internal and external) is enclosed by a thickened basement membrane, the glassy membrane, and a connective tissue root sheath which is essentially dermal tissue.

Epidermal Dendritic cells

- aka Langerhans cells -immunity

Keratin

- fibrous protein that gives the epidermis its durability and protective capabilities -connected to each other by desmosomes

Stratum Basale (basal layer)

-10% - 25% of the cells in this stratum are melanocytes - basal layer -rapid cell division -adequate diffusion

Stratum Spinosum (spiny layer)

-Largest layer of the epidermis. Under the stratum granulosum layer -contain thick weblike bundles of intermediate filaments made of pre keratin protein -adequate diffusion

Eccrine Glands

-aka merocrine sweat glands -distributed all over the body -produce clear perspiration consisting primarily of water, salts, and urea -heat regulating apparatus

Epidermis

-avascular -keratinized stratified squamous -4 distinct cell types and 4/5 distinct layers

Reticular Layer

-deepest skin layer -dense irregular CT and contains many arteries and veins. sweat and sebaceous glands, and pressure receptors (pacinian corpuscles)

Dermis

-dense irregular CT making up this -Papillary and reticular areas -richly provided with lymphatic vessels and a nerve supply

Skin/integument

-insulates and cushions the underlying body tissues and protects the entire body from mechanical , chemical damage, thermal damage, and bacterial invasion;prevents water loss; regulates heat loss; mini-excretory system; chemical conversions (vitamin D synthesis); sense organs (dermis)

Papillary layer

-more superficial dermal region composed of areolar CT. Uneven and has finger like projections from its superior surface (dermal papillae- attach it to the epidermis) -lie on top of the larger dermal reidges -produce fingerprints -abundant capillary networks

keratinocytes

-most abundant epidermal cells, mainly to produce keratin fibrils

Sweat (sudoriferous) glands

-outlets for the glands are epithelial openings called pores

Apocrine

-primarily in the axillary and genital areas -secrete a milky protein and fat rich substance

Stratum Corneum (horny layer)

-the outermost epidermal layer consists of some 20 - 30 cell layers -accounts for the bulk of the epidermal thickness -dead -flattened scalelike remnants are fully keratinized -carotene

Stratum Granulosum (granular layer)

-thin layer named for the abundant granules its cells contain 1. lamellated granules - waterproofing glycolipid that is secreted into the extracellular space 2. keratohyaline granules - combine with the intermediate filaments in the more superfical layers to form the keratin fibrils

Stratum lucidum (clear layer)

-thin, translucent band of flattened dead keratinocytes with indistinct boundaries -not present in regions of thin skin -dead

_____ glands are found primarily in the genital and axillary areas

Apocrine

these cells produce a brown to black pigment that colors the skin and protects DNA from the damaging effects of UV radiation

Melanocytes

The portion of the hair that you see that projects from the scalp surface is known as the

Shaft

Melanocytes

Spidery black cells that produce the borwn to black pigment called melanin

Lunule

The proximal region of the thickened nail matrix, which appears as a white crescent (blood supply in the underlying dermis)

Hypodermis/superficial fascia

The subcutaneous tissue deep to the skin. It is not part of the skin, but it shares some of the skins protective functions. It is superficial to the tough connective tissue wrapping (fascia) of the skeletal muscles, consists mostly of adipose tissue. Functions: Anchors the skin to the underlying structures (mostly muscle), acts as a shock absorber.

(T/F) nails are hornlike derivatives of the epidermis

True

hair bulb

collection of well nourished germinal epithelial cells at the basal end of the follicle

If the environment is cool and the body heat must be conserved, the arterioles ___ so that blood bypasses the dermal capillary networks temporarily

constrict

When body temp high, the arterioles serving the skin ____ and the capillary network of the dermis becomes engorged with heated blood

dilate

hair root

enclosed within the follicle

The skin has two distinct regions. The superficial layer is the ______ and the underlying CT, the _______

epidermis; dermis

Nail bed

extension of the stratum basale beneath the nail

Sebaceous (oil) glands

found nearly all over the skin except for the palms of the hands and soles of the feet

Tactile (merkel ) cells

occasional spiky hemispheres that form sensitive touch receptors located at the epidermal-dermal junction

hair shaft

portion projecting from the scalp surface

Sebum

products of sebaceous glands -mixture of oily substances and fragmented cells that acts as a lubricant to keep the skin soft and moist and keeps hair from becoming brittle

The ducts of _____ glands usually empty into a hair follicle but may also open directly on the skin surface

sebaceous

Cutaneous glands

sebaceous glands and the sweat glands

All the following are functions of the skin except excretion of body wastes insulation protection from mechanical damage site of vitamin A synthesis

site of vitamin A synthesis

Nail Folds

skin folds that overlap border of nail

Arrector pili muscle

small bands of smooth muscle cells connect each hair follicle to the papillary layer of the dermis

Papilla

small nipple of dermal tissue that protrudes int o the hair bulb from the CT sheath and provides nutrition to the growing hair

hair

structure consisting of a medulla, a central region surrounded first by the cortex and then by the protective cuticle .

Root

the part that is embedded in the skin and adheres to an epithelial nail bed

Free edge

the portion of the nail that grows out away from the body

Eponychium

the thick proximal nail fold commonly called the cuticle

Nail Body

the visible attached portion

Nail Matrix

thickened proximal portion of the nail bed; responsible for nail growth


Related study sets

Maternal & Newborn Health - Archer Review (1/2)

View Set

English - Including Quotations in Your Writing

View Set

Topic 6 -Energy Flow In Ecosystems

View Set

Chapter 12: Lymphatic and Immune Systems

View Set

Ch 9 Alterations in Immunity and Inflammation

View Set