Chr. 5 - Integumentary System

Question 1

[5.1] What are the two components of the cutaneous membrane?

Answer 1

Epidermis and dermis.

Question 2

[5.1] What are lamellated corpuscles?

Answer 2

Nerve endings sensitive to pressure.

Question 3

[5.1] What is deep to the dermis?

Answer 3

The subcutaneous layer.

Question 4

[5.1] Describe the epidermis.

Answer 4

A layer of keratinized stratified squamous epithelium, composed of four types of cells: keratinocytes, melanocytes, intraepidermal macrophages, and tactile epithelial cells.

Question 5

[5.1] What are keratinocytes?

Answer 5

Cells that produce the keratin, a tough fibrous protein protecting the skin and layers deep to it, and lamellar granules.

Question 6

[5.1] What are lamellar granules?

Answer 6

Secretory organelles secreted by keratinocytes, forming a water-repellant membrane.

Question 7

[5.1] What are melanocytes?

Answer 7

Cells in the epidermis that produce melanin.

Question 8

[5.1] What is melanin?

Answer 8

A yellow-red or brown-black pigment able to absorb UV light, responsible for shade of skin.

Question 9

[5.1] What are intraepidermal macrophages?

Answer 9

Cells participating in immune responses by recognizing foreign microbes.

Question 10

[5.1] What are tactile epithelial cells?

Answer 10

Cells containing a tactile disc, aiding in detecting of touch sensation.

Question 11

[5.1] What is thin skin?

Answer 11

Regions of the epidermis where only four strata are present: stratum basale, spinosum, granulosum, and corneum.

Question 12

[5.1] What is thick skin?

Answer 12

Regions of the epidermis where five strata are present: stratum basale, spinosum, granulosum, and corneum, and lucidum.

Question 13

[5.1] What is the stratum basale?

Answer 13

The deepest layer of the epidermis composed of a single row of cuboidal or columnar keratinocytes.

Question 14

[5.1] What is the stratum spinosum?

Answer 14

Layer of keratinocytes about 8-10 layers thick, containing coarser bundles of keratin that extend into the desmosomes, providing increased strength and flexibility.

Question 15

[5.1] What is the stratum granulosum?

Answer 15

Layer of epidermis superficial to spinosum, where keratinocytes are undergoing apoptosis. Presence of keratohyalin defines this layer, which is responsible for forming lamellar granules.

Question 16

[5.1] What is the stratum lucidum?

Answer 16

Layer of epidermis superficial to granulosum, consisting of 4-6 layers of clear dead keratinocytes, providing additional toughness.

Question 17

[5.1] What is the stratum corneum?

Answer 17

Layer of epidermis most superficial, consisting of 25-30 layers of dead keratinocytes.

Question 18

[5.1] Describe the process of keratinization.

Answer 18

Cells moving from the stratum basale to the stratum corneum, accumulating more keratin as they progress.

Question 19

[5.1] Describe the dermis.

Answer 19

Deeper part of the skin composed of dense irregular connective tissue containing collagen and elastic fibers.

Question 20

[5.1] What is the papillary region?

Answer 20

Superficial region containing collagen and fine elastic fibers.

Question 21

[5.1] What are dermal papillae?

Answer 21

Dome-shaped structures of papillary region projecting to underside of epidermis, increasing surface area.

Question 22

[5.1] What are free nerve endings?

Answer 22

Dendrites that lack structural specialization, found in dermal papillae.

Question 23

[5.1] Describe the reticular region.

Answer 23

Layer of dermis attaching to subcutaneous layer, contains thick collagen fibers, fibroblasts, and wandering cells. Provides strength, extensibility, and elasticity.

Question 24

[5.1] What are epidermal ridges?

Answer 24

A series of ridges and grooves present on the tips of digits, creating strong bonds between epidermis and dermis as well as increasing surface area for grip.

Question 25

[5.1] Which pigments impart shades to skin?

Answer 25

Melanin, hemoglobin, and carotene.

Question 26

[5.2] Describe *hair*.

Answer 26

Columns of dead keratinized epidermal cells bonded by extracellular proteins.

Question 27

[5.2] What is the *hair shaft*?

Answer 27

Superficial portion of the hair projecting above the surface of the skin.

Question 28

[5.2] What is the *hair root*?

Answer 28

Portion of the hair deep to the skin, projecting from either the dermis or the subcutaneous layer.

Question 29

[5.2] What is the *hair follicle*?

Answer 29

A structure made of the epithelial root sheath, and the dermal root sheath

Question 30

[5.2] What two compnents make up the epithelial root sheath?

Answer 30

The external root sheath and the internal root sheath.

Question 31

[5.2] What is the *external root sheath*?

Answer 31

Part of the hair follicle formed by the downward extension of the epidermis.

Question 32

[5.2] What is the *internal root sheath*?

Answer 32

A sheath formed by epithelium between external root sheath and the hair.

Question 33

[5.2] What is the dermal root sheath?

Answer 33

Dense dermis surrounding the epithelial root sheath.

Question 34

[5.2] What is the *hair bulb*?

Answer 34

The base of a hair follicle and it's surrounding dermal root sheath.

Question 35

[5.2] What is the *papilla of the hair*?

Answer 35

A dome-shaped indentation containing areolar connective tissue and blood vessels, nourishing the hair follicle.

Question 36

[5.2] What is *arrector pili*?

Answer 36

Smooth muscles within the dermis attached to hairs, controlling movement of hair via contractions.

Question 37

[5.2] Describe a *sebaceous gland*.

Answer 37

Simple branched acinar glands secretion secreting sebum.

Question 38

[5.2] What is *sebum*?

Answer 38

A mixture of triglycerides, cholesterol, proteins, and inorganic salts.

Question 39

[5.2] Describe a *sudoriferous gland*.

Answer 39

Glands secreting sweat, classified into eccrine and apocrine.

Question 40

[5.2] What is an *eccrine sweat gland*?

Answer 40

Simple coiled tubular glands deep in dermis that open to the surface of epidermis.

Question 41

[5.2] What is an *apocrine gland*?

Answer 41

Simple coiled tubular glands with larger ducts and lumens that open to hair follicles.

Question 42

[5.2] Describe *ceruminous gland*.

Answer 42

Glands present in subcutaneous layer in the external auditory canal and secrete cerumen.

Question 43

[5.2] Describe a *nail*.

Answer 43

Plates of tightly packed, hard, dead keratinized epidermal cells.

Question 44

[5.2] List the components of a nail.

Answer 44

1. Nail body. 2. Free edge. 3. Nail root. 4. Lunula 5. Hyponychium 6. Nail bed 7. Eponychium 8. Nail matrix.

Question 45

[5.3] What are the types of skin?

Answer 45

Thin (hairy) skin and thick (hairless) skin.

Question 46

[5.4] What are the functions of skin?

Answer 46

Thermoregulation, blood reservoir, protection, excretion and absorption, cutaneous sensation, synthesis of vitamin D.