A&P Lab 7: The Integumentary System

Question 1

Epidermis

Answer 1

outer, superficial layer of the skin

Question 2

Dermis

Answer 2

inner, deep layer of the skin

Question 3

Hypodermis

Answer 3

tissue beneath the dermis (subcutaneous layer); not a part of the skin, but instead a loose configuration of fat and areolar tissue that attaches the skin to the underlying muscles

Question 4

Keratinocytes

Answer 4

cells that make up roughly 90% of the epidermal cells and undergo keratinization

Question 5

Melanocytes

Answer 5

produce the brown pigment, melanin

Question 6

Langerhans cells

Answer 6

phagocytic cells that provide defense against infection

Question 7

Merkel cells

Answer 7

located deep in the dermis and function as touch receptors

Question 8

Stratum basale

Answer 8

single layer of cells adjacent to the dermis, which are columnar or cuboidal in shape and activetly produce new cells by mitosis

Question 9

Stratum spinosum

Answer 9

8-10 rows of cells, mainly keratinocytes; has the appearance of spines protruding from the cells, caused by the tissue preparation process

Question 10

Stratum granulosum

Answer 10

3-5 rows of keratinocytes; the flattened cells contain tiny granules (keratohyaline & lamellated granules) in the cytoplasm, a sign that the cells are producing keratin as part of the keratinization process

Question 11

Stratum lucidum

Answer 11

3-5 rows of flattened, dead keratinocyte ghosts that are mainly keratin; the dead cells appear almost translucent; layer only found in the thick skin of the palms/soles

Question 12

Stratum corneum

Answer 12

thick, outer layer of 25+ rows of flattened, dead keratinoctyes that have become saturated with keratin to produce a touch, water-repellant layer

Question 13

Papillary region

Answer 13

part of the dermis adjacent to the stratum basale; consists of a thin region of areolar tissue arranged in finger-like ridges poking up toward the epidermis; individual projections = dermal papillae (form the ridges/whorls of the skin surface in the fingers, palms, toes, and soles)

Question 14

Reticular region

Answer 14

dominant, deep part of the dermis that is composed of dense irregular connective tissue with abundant collagen fibers, elastic fibers, and blood vessels

Question 15

Hairs

Answer 15

found throughout the surface of the skin, except in the thick-skinned parts of the body (palms/soles), the lips, the nipples, and parts of the external genitals

Question 16

Shaft

Answer 16

part of a hair that projects from the skin surface

Question 17

Root

Answer 17

submerged portion of a hair

Question 18

Hair follicle

Answer 18

sheath of epithelium extending downward into the dermis

Question 19

Arrector pili muscle

Answer 19

small band of smooth muscle associated with the hair follicle

Question 20

Hair bulb

Answer 20

well-nourished swelling of germinal epithelial cells

Question 21

Matrix

Answer 21

new cells are produced at the hair bulb within a cluster of cells known as this, which push upward from the growth area and eventually die and become keratinized

Question 22

Papilla

Answer 22

cells of the matrix receive nourishment from blood vessels within a connective tissue _______

Question 23

Medulla

Answer 23

central core of a hair

Question 24

Cortex

Answer 24

outer region of keratinized cells that surround the medulla

Question 25

Cuticle

Answer 25

outer protective layer of keratinized cells that surround the cortex

Question 26

Nail

Answer 26

flat, hart structure composed of keratinized epidermis

Question 27

Body

Answer 27

visible, pink portion of the nail

Question 28

Root

Answer 28

part of the nail that is embedded in the skin that attaches to the epidermis

Question 29

Free edge

Answer 29

at the distal end of the body extending away from attached areas is this

Question 30

Nail matrix

Answer 30

at the proximal end of the body containing the germinal cells that divide to produce this new nail material

Question 31

Lunula

Answer 31

lighter part of the nail body at the proximal end

Question 32

Cuticle

Answer 32

AKA eponychium; skin folding over the proximal end of the nail

Question 33

Sebaceous glands

Answer 33

produce an oily product (sebum), which is deposited into ducts that usually empty into hair follicles; found wherever hair follicles are present

Question 34

Sweat glands

Answer 34

AKA sudoriferous glands; located deep in the dermis where they produce a watery material; the product is deposited into long ducts that empty onto the skin surface at pores

Question 35

Eccrine glands

Answer 35

widely distributed, produce watery perspiration as a means of regulating body temperature

Question 36

Apocrine glands

Answer 36

produce a thickened secretion after puberty and are found mainly in the axillary and genital regions

Question 37

Sensory receptors

Answer 37

specialized endings of sensory neurons that generate and electrochemical signal when they experience a change in the environment (temperature, pressure, or fine touch)

Question 38

Meissner's corpuscles

Answer 38

Corpuscle of Touch in the papillary region of the dermis; sensitive to fine touch; rod-shaped swellings at the end of sensory neurons adjacent to the stratum basale of the epidermis

Question 39

Pacinian corpuscles

Answer 39

AKA Lamellated corpuscle; in the reticular region of the dermis; sensitive to pressure; large, round swellings with numerous rings of protein fibers, giving them the appearance of a sliced onion in a section through the skin