Integumentary System Overview

Question 1

What are the two main components of the integumentary system?

Answer 1

Skin and epidermal derivatives

Question 2

What are four examples of epidermal derivatives>

Answer 2

1. hair follicles and hair
2. sweat (sudoriferous) glands
3. sebaceous (oil) glands
4. nails

Question 3

What are the major functions of the integumentary system? (6)

Answer 3

Protective, immunologic, homeostasis, sensory, endocrine, and exocrine

Question 4

What are the two principle layers of the skin?

Answer 4

Epidermis and the dermis

Question 5

What kind of epithelium is the epidermis?

Answer 5

Keratinized stratified squamous epithelium

Question 6

Is the epithelium vascular or avascular?

Answer 6

Avascular

Question 7

The epidermis is derived from what embryonic tissue?

Answer 7

Ectoderm

Question 8

Generally what kind of tissue is the dermis?

Answer 8

Connective tissue

Question 9

What embryonic tissue is the dermis derived from?

Answer 9

Mesoderm

Question 10

Is the dermis vascular or avascular?

Answer 10

Highly vascularized

Question 11

What is the layer of tissue deep to the skin?

Answer 11

Hypodermis (subcutaneous layer/subcutaneous fascia), consists of adipose tissue and is vascularized

Question 12

What are the 4 cells of the epidermis?

Answer 12

Keratinocytes (85%), melanocytes (5%), Langerhans’ cells (2-5%), and Merkel’s cells (6-10%)

Question 13

What do keratinocytes do?

Answer 13

Produce keratins, and participate in formation of water barrier

Question 14

What do melanocytes do?

Answer 14

Produce pigment

Question 15

What are Langerhans’ cells of the epidermis?

Answer 15

Antigen presenting cells of the immune system

Question 16

What are Merkel’s cells?

Answer 16

Mechanoreceptor cells associated with sensory nerve endings

Question 17

What is the major structural protein of the epidermis?

Answer 17

Keratins

Question 18

Keratins are classified as what kind of filaments?

Answer 18

Intermediate filaments, more commonly referred to as tonofilaments

Question 19

Describe the stratum basale layer of the epidermis.

Answer 19

• Single layer of basophilic cells,
• cells are small and cuboidal/low columnar
• mitotically active layer; contains stem cells tha tgive rise to keratinocytes
• production of intermediate (keratin) filaments begins

Question 20

What two things begin production in the stratum spinosum layer?

Answer 20

Keratohyalin granules and lamellar bodies

Question 21

Stratum granulosum layer stains what?

Answer 21

Intensely basophilic

Question 22

Granular cells in the stratum granulosum layer turn into what?

Answer 22

Cornified cells (keratinization)

Question 23

Describe the histologic appearance of stratum lucidum.

Answer 23

Thin, translucent layer of eosinophilic cells. Nucleus and cytoplasmic organelles become disrupted and disappear

Question 24

Describe what is found in the cells of the stratum corneum.

Answer 24

Cells lose nuclei and cytoplasmic organelles. They are filled almost entirely with keratin (85%)

Question 25

Melanin is synthesized and stored in what?

Answer 25

Melanosomes

Question 26

Melanocytes are what kind of cells?

Answer 26

Dendridic cells

Question 27

Why does melanin accumulate over the nuclei of cells?

Answer 27

To protect DNA from UV radiation

Question 28

Describe a histologic appearance of a melanocyte.

Answer 28

Elongated nuclei surrounded by clear cytoplasm

Question 29

Antigen presenting cells are typically found in what epidermal layer?

Answer 29

Stratum spinosum

Question 30

What tissue are antigen presenting cells derived from?

Answer 30

Bone-marrow

Question 31

What do the antigen presenting cells do?

Answer 31

Present processed antigen to T lymphocytes within nearby lymph node

Question 32

What epidermal layer are mechanoreceptor cells found?

Answer 32

Within the stratum basale

Question 33

What is merkel's corpuscle?

Answer 33

This structure is the base of merkel's cells that associate with expanded plate-like terminal of afferent nerve fibers

Question 34

What are the three types of skin cancer?

Answer 34

Basal cell carcinoma, squamous cell carcinoma, and malignant melanoma

Question 35

What are three characteristics of basal cell carcinoma?

Answer 35

- Most common - Resembles cells of stratum basale - Slow-growing tumor

Question 36

What are two characteristics of squamous cell carcinoma?

Answer 36

- Second most common | - Characterized by highly atypical cells at all levels of epidermis

Question 37

What are three characteristics of malignant melanoma?

Answer 37

- Most serious form - Originates from melanocytes - Presents as irregularly pigmented, multicolor lesion

Question 38

What are the two layers of the dermis?

Answer 38

Papillary layer and the reticular layer

Question 39

The papillary layer is consisted of what connective tissue?

Answer 39

Loose (areolar) connective tissue

Question 40

Describe the histologic appearance of the papillary layer of the dermis.

Answer 40

Dermal papillae: finger-like connective tissue protrusions that project into the epidermis at the epidermal-dermal junction

Question 41

The reticular layer of the dermis is what kind of connective tissue?

Answer 41

Dense irregular connective tissue

Question 42

Is the papillary layer or the reticular layer of the dermis thicker?

Answer 42

Reticular layer is considerably thicker

Question 43

Does the papillary layer or the reticular layer have more cells?

Answer 43

Papillary layer

Question 44

Where would one find pacinian corpuscles?

Answer 44

These structures are found in the dermis and hypodermis

Question 45

Describe the structure of pacinian corpuscles?

Answer 45

Large ovoid structures that are myelinated nerve ending surrounded by a capsule consisting of concentric lamellae. The inner core is a series of tightly packed, flattened Schwann cell lamellae surrounding unmyelinated axon

Question 46

What do pacinian corpuscles do?

Answer 46

Detect pressure and vibration

Question 47

Where are meissner's corpuscles found?

Answer 47

Within dermal papillae of hairless skin

Question 48

What kind of flattened cells form the lamellae of meissner's corpuscles?

Answer 48

Schwann cells

Question 49

What do meissner's corpuscles do?

Answer 49

Detect light touch

Question 50

Define hair.

Answer 50

Elongated filamentous, keratinized structures that project from hair follicles

Question 51

What is the hair follicle responsible for?

Answer 51

The production and growth of a hair

Question 52

Where is hair and hair follicles found?

Answer 52

Along the surface of almost the entire body, but definitely NOT associated with thick skin

Question 53

What is the smooth muscle that extends from connective tissue sheath surrounding the hair follicle to the papillary layer of dermis?

Answer 53

Arrector pili muscle

Question 54

What kind of innervation do arrector pili muscle receive?

Answer 54

Sympathetic

Question 55

What role do arrector pili muscles serve?

Answer 55

Insulation

Question 56

What leads to body odor?

Answer 56

Bacterial breakdown of sweat

Question 57

Sebaceous (oil) glands are found where?

Answer 57

Everywhere in the skin except thick skin

Question 58

What type of gland are sebaceous glands?

Answer 58

Branched acinar glands

Question 59

Define sebum.

Answer 59

Lipid-containing substance produced and secreted by gland

Question 60

Where do sebaceous glands secrete their product?

Answer 60

Into hair follicle

Question 61

What kind of secretion comes from sebaceous glands?

Answer 61

Holocrine

Question 62

What gland is involved in acne development?

Answer 62

Sebaceous (oil) glands

Question 63

Define finger nails and toe nails.

Answer 63

Plates of keratinized cells that rest on nail beds