Chapter 5 The Integumentary System - Study Guide

Function of Apocrine Sweat Glands

Begin functioning during puberty and are active during emotional sweating; They are stimulated during emotional stress and sexual excitement (DO NOT PLAY A ROLE IN BODY TEMPERATURE REGULATION)

The superficial region of the dermis contains _____

Blood vessels, nerves, hair follicles, dermal papillae, and corpuscles of touch

*Functions of the Skin:*

Body temperature regulation; Protection; Cutaneous Sensations; Excretion and absorption; Synthesis of vitamin D

Intraepidermal Macrophages (Langerhans Cells)

Cells of the skin that are active in the immune process

Melanocytes

Cells producing the pigment responsible for skin color (melanin)

Keratinocytes

Cells that produce keratin (*helps waterproof and protect the skin and underlying cells* from abrasions, heat, microbes, and chemicals)

Tactile Epithelial Cells (Merkel Cells)

Detect touch sensations

Types of Sudoriferous Glands:

Eccrine and apocrine

Skin coloration changes when _____

Exposed to ultraviolet radiation of the sun

The deepest part of the skin is composed of dense regular connective tissue.

False

*Ceruminous glands*

Glands that are present in the external auditory meatus (outer ear canal)

*Sebaceous Glands (oil glands)*

Glands that secrete an oily substance called sebum and are glands usually associated with hair follicles

-Keratinization

Process by which cells form in the stratum basale, rise to the surface, become keratinized, slough off, and are replaced by underlying cells.

Cell division of the nail matrix cells _____

Produces new nails

Function of Hair:

Protection

The epidermis is associated with _____

Protection from the ultraviolet light

Function of Cerumen:

Provides sticky barrier that impedes the entrance of foreign bodies & insects; Waterproofs the canal; Prevents bacteria and fungi from entering cells

Types of Glands Associated with the Skin:

Sebaceous (oil); sudoriferous (sweat); ceruminous

*Glands*

Single or groups of epithelial cells that secrete a substance

The Integumentary System Components:

Skin, hair, nails, oil and sweat glands, and sensory receptors

Stratum Corneum

Sloughs off dead skin (most superficial layer).

Dermal Papillae

Small, fingerlike, nipple-shaped projections that greatly increase the surface area of the dermis

Layers of the Epidermis from Deep to Superficial:

Stratum Basale; Stratum Spinosum; Stratum Granulosum; Stratum Lucidum (thick, hairless skin only); Stratum Corneum

In which portion of the skin will you find dermal papillae?

Superficial region of the dermis

Hair Follicle

Surrounds the root and is composed of 2 layers of epidermal cells, external and internal root sheaths, surrounded by a connective tissue sheath

*Hair*

Threads of fused, dead, keratinized epidermal cells

What is the result of aging in the skin?

Wrinkling, loss of subcutaneous fat, atrophy of sebaceous glands, and decreases in the number of melanocytes and intraepidermal macrophages.

Carotene

Yellow-orange pigment that gives carrots and egg-yolks their color. When an excessive amount is eaten, it may accumulate in the stratum corneum, fatty, areas of the dermis, and subcutaneous layer and turns skin color orange

Superificial Region of the Dermis:

Consists of areolar connective tissue containing fine elastic fibers

Cuticle

Consists of stratum corneum of the epidermis

Apocrine sweat _____

Contains the same components as eccrine sweat plus lipids and proteins & Is odorless but has odor when it interacts with bacteria on the skin surface

Most of the age-related changes begin at _____ and occur in _____

About age 40; proteins in the dermis

The deepest part of the dermis contains _____

Adipose cells, hair follicles, nerves, oil glands, and sweat glands

The hypodermis (subcutaneous layer) consists of _____

Areolar and adipose tissue with pressure-sensitive nerve endings.

Hairs are associated with _____ and _____

Arrector pili and sebaceous glands

Free Nerve Endings

Associated with sensations of warmth, coolness, pain, tickling, and itching.

Deeper Part of the Dermis:

Attached to the subcutaneous layer, consists of dense irregular connective tissue with bundles of collagen and some coarse elastic fibers.

Nails

Plates of tightly packed, hard, dead, keratinized epidermal cells covering the terminal portions of the fingers and toes

Which tissue is the main type found in the deeper region of the dermis?

dense irregular connective

Function of Nails:

Nails help us grasp & manipulate small objects; Provide *protection* to the ends of fingers & toes; and allow us to scratch various parts of the body

Corpuscles of Touch (Meissner corpuscles)

Nerve endings that are sensitive to touch

Hair Root Plexuses

Nerve endings that surround each hair follicle and are sensitive to touch

The dermis contains

Nerve endings, sweat glands and oil glands, hair follicles, and blood vessels.

Papilla of the Hair

Nipple-shaped indentation that contains many blood vessels and provides nourishment for the growing hair

Sebum

Oily substance that keeps hair from drying out, prevents excessive evaporation of water from the skin, keeps the skin soft, and inhibits certain bacteria

The ducts of apocrine sweat glands _____

Open into hair follicles

There are no sebaceous glands in the _____

Palms and soles

The skin provides _____ that help protect the body

Physical, chemical, and biological barriers

Tattooing

A permanent coloration of the skin in which a foreign pigment is deposited with a needle into the dermis.

Hair Matrix

A region of cells inside the hair bulb that produces new hairs by cell division when older hairs are shed

Nail Bed

A thickened area of stratum corneum beneath the free edge that attached the free edge to the fingertip

The combined secretion of the ceruminous and sebaceous glands is _____

A yellowish secretion called cerumen or earwax

-To prevent an unwanted hair from growing back, you must destroy the ___.

Hair matrix

Structure of Hair:

Hair shaft; hair root; hair follicle;

Accessory Structures of the Skin:

Hair; glands; nails

Function of Glands:

Help regulate body temperature

Potential problems associated with body piercing:

Infections, allergic reactions, scarring, and anatomic damage (such as nerve damage or cartilage deformation

Types of Cells in the Epidermis:

Keratinocytes; Melanocytes; Intraepidermal Macrophages (langerhans cells); Tactile Epithelial Cells (merkel cells)

The skin participates in body temperature regulation by _____

Liberating sweat at its surface and by adjusting the flow of blood in the dermis

The secreting portions of the sebaceous glands _____

Lie in the dermis and open into the hair follicles or directly onto a skin surface

Apocrine Sweat Glands

Limited in distribution and found mainly in the skin of the armpit, groin, areolae of breasts, and bearded regions of the face in adult males

*What proteins (or pigments) are involved in skin color?*

Melanin, hemoglobin, carotene

Eccrine Sweat Glands

Most prevalent sweat glands distributed throughout most of the body, especially in the skin of the forehead, palms, and soles

Components of the Nail:

Nail body; free edge; nail bed; nail root; lunula; cuticle; nail matrix

Nail growth originates at the _____

Nail matrix

The ducts of eccrine sweat glands _____

Terminate at pores at the surface of the epidermis

Melanin

The amount of it causes the skin's color to vary from pale yellow to reddish-brown to black; Pigment found in specialized cells of the stratum basale

Hair Bulb

The base of a hair follicle that is enlarged into an onion-shaped structure

Arrector Pili Muscle

The bundle of smooth muscles associated with hair follicles

*Sudoriferous Glands (sweat glands)*

The cells of these glands release sweat, or perspiration, into hair follicles or onto the skin surface through pores. Excrete perspiration and detoxify the body by excreting salt and unwanted chemicals

*Dermis*

The deeper, thicker portion of the skin; is composed primarily of connective tissue containing collagen and elastic fibers

Body Piercing

The insertion of jewelry through an artificial body opening

Most effects of aging occur when an individual reaches ____

The late fourties

*Subcutaneous Layer*

The later below the dermis, but not part of the skin

Stratum Lucidum

The layer of the epidermis primarily found in the thick skin of fingertips, palms, and soles

Stratum Granulosum

The layer of the epidermis that contains keratin and lamellar granules. Keratinocytes undergo apoptosis here (genetic programmed cell death).

Stratum Spinosum

The layer of the epidermis that provides strength and flexibility

Stratum Basale

The layer of the epidermis which contains cells capable of continued cell division (produces all other layers in a process called keratinization); (MELANIN IS FOUND IN THE SPECIALIZED CELLS OF THE STRATUM BASALE)

Eccrine sweat glands are not present in _____

The margins of the lips, nail beds of the fingers and toes, glans penis, glans clitoris, labia minora, and eardrums.

*Epidermis*

The outermost portion of the skin; is composed of epithelial tissue; (CONTAINS DEAD CELLS FILLED WITH KERATIN)

Hemoglobin

The oxygen-carrying pigment in red blood cells that causes skin to appear red

Hair is present on most skin surfaces except _____

The palms, palmar surfaces of the fingers, soles, and plantar surfaces of the toes

Free Edge

The part of the body that extends past the end of the finger or toe

Hair Root

The portion below the surface that penetrates into the dermis and subcutaneous layer

Nail Body

The portion of the nail that's visible

Nail Root

The portion that's not visible

Nail Matrix

The proximal portion of the epithelium deep to the nail root; Contains dividing cells, which produce new nail cells.

Hair Shaft

The superficial portion of the hair above the surface

Lunula

The whitish semilunar area near the nail root

Function of Eccrine Sweat Glands

Their main function is to regulate body temperature but they also release sweat in response to emotional stress (such as fear or embarrassment)