Lab Integumentary System

Question 1

is considered an organ system because it consists of multiple organs, the skin and its accessory organs

Answer 1

integument

Question 2

The skin has many functions, most concerned with

Answer 2

Protection

Question 3

The skin has two distinct regions

Answer 3

Superficial epidermis and the dermis

Question 4

Immediately deep to the dermis is the — or hypodermis,

Answer 4

Subcutaneous layer

Question 5

Structurally, this is a keratinized stratified squamous epithelium consisting of four distinct cell types and four or five distinct layers.

Answer 5

Epidermis

Question 6

Cell types of epidermis

Answer 6

Keratinocytes, melanocytes, dendritic cell, and tactile epithelial cell

Question 7

The most abundant epidermal cells, their main function is to produce keratin fibrils

Answer 7

Keratinocytes

Question 8

is a fibrous protein that gives the epidermis its durability and protective capabilities.

Answer 8

Keratin

Question 9

Spidery black cells that produce the brown-to-black pigment called melani

Answer 9

Melanocytes

Question 10

Also called Langerhans cells, these cells arise from the bone marrow and migrate to the epidermis.
They ingest foreign substances and play a key role in acti-vating the immune response.

Answer 10

Dendritic cells

Question 11

Occasional spiky hemispheres that, in combination with sensory nerve endings, form sensitive touch receptors located at the epidermal-dermal junction.

Answer 11

Tactile epithelial cells:

Question 12

The outermost layer consisting of 20–30 layers of dead, scalelike keratinocytes. They are constantly being exfoliated and replaced by the division of the deeper cells.

Answer 12

Stratum corneum (horny layer)

Question 13

Present only in thick skin. A very thin transparent band of flattened, dead keratinocytes with indistinct boundaries

Answer 13

Stratum lucidum (clear layer)

Question 14

A thin layer named for the abundant granules its cells contain. These granules are (1) lamellar granules, which contain a waterproofing glycolipid that is secreted into the extracellular space; and (2) keratohyaline granules, which help to form keratin in the more superficial layers. At the upper border of this layer, the cells are beginning to die.

Answer 14

Stratum granulosum (granular layer)

Question 15

Several layers of cells that contain thick, weblike bundles of intermediate filaments made of a pre-keratin protein. The cells in this layer appear spiky because when the tissue is prepared, the cells shrink, but their desmosomes hold tight to adjacent cells. Cells in this layer and the basal layer are the only ones to receive adequate nourishment from diffusion of nutrients from the dermis.

Answer 15

Stratum spinosum (spiny layer)

Question 16

The more superficial dermal region com-
posed of areolar connective tissue. It is very uneven and has

fingerlike projections from its superior surface,

Answer 16

Papillary dermis

Question 17

, which attach it to the epidermis above. These
projections lie on top of the larger dermal ridges. In the
palms of the hands and soles of the feet, they produce the
fingerprints, unique patterns of epidermal ridges that remain
unchanged throughout life.

Answer 17

dermal
papillae

Question 18

The deepest skin layer. It is composed of dense irregular connective tissue and contains many arteries and veins, sweat and sebaceous glands, and pressure receptors (lamellar corpuscles).

Answer 18

Reticular dermis

Question 19

The visible attached portion.

Answer 19

Nail plate

Question 20

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

Answer 20

Free edge

Question 21

The region beneath the free edge of the nail.

Answer 21

Hyponychium

Question 22

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

Answer 22

Nail root

Question 23

Skin folds that overlap the borders of the nail.

Answer 23

Nail folds

Question 24

Projection of the thick proximal nail fold commonly called the cuticle.

Answer 24

Eponychium

Question 25

Extension of the stratum basale beneath the nail.

Answer 25

Nail bed

Question 26

The thickened proximal part of the nail bed containing germinal cells responsible for nail growth. As
the matrix produces the nail cells, they become heavily keratinized and die. Thus nails, like hairs, are mostly non-
living material.

Answer 26

Nail matrix

Question 27

The proximal region of the thickened nail matrix,
which appears as a white crescent moon. Everywhere else, nails are transparent and nearly colorless, but they appear pink because of the blood supply in the underlying dermis. When someone is cyanotic because of a lack of oxygen in
the blood, the nail beds take on a blue cast.

Answer 27

Lunule