Lecture 7- Integument

Question 1

A 44 year old female is told that she has skin cancer. Some type of carcinoma! This would be cancer of what part of the skin?

Answer 1

Epidermis

Question 2

What is the outermost epithelial layer?

Answer 2

Epidermis

Question 3

What is the layer of connective tissue under the epidermis?

Answer 3

Dermis

Question 4

What is the layer of connective tissue under the dermis?

Answer 4

Hypodermis

Question 5

Where are keratinocytes found?

Answer 5

In the dead and alive tissue of the stratified squamous epithelial cells.

Question 6

As basal cells divide, they move toward which surface?

Answer 6

the apical surface to slough off

Question 7

Does the thickness of the epidermal layer change?

Answer 7

no, it is a very orderly process

Question 8

What are melanocytes?

Answer 8

Dendritic processes that make melanin. Found in the basement membrane.

Question 9

What are Langerhans cells

Answer 9

Dendritic processes that are immune cells

Question 10

Where are Tacticle (Merkel) cells found?

Answer 10

In the basement membrane connecting to a sensory nerve ending

Question 11

There is thick skin and think skin. How do they differ?

Answer 11

The epidermis is thicker in thicker in skin

Question 12

What characterizes the stratum basale? (5)

Answer 12

• one cell layer thick
• cuboidal or columnar cells
• contains hemidesmosomes
• mitotic cells
• contains desmosomes

Question 13

What characterizes the stratum spinosum? (5)

Answer 13

• does not contain hemidesmosomes
• contains desmosomes
• has some mitotic cells
• thicker in thick skin than in thin skin
• Active cells

Question 14

How are tonofibrils formed?

Answer 14

Keritanocytes in the stratum spinosum produce keratin that forms the intermediate filaments or tonofibrils in the epidermis.

Question 15

Intermediate filaments are involved in intercellular adhesion. Is this via adherent junctions, desmosomes, or tight junctions?

Answer 15

Desmosomes

Question 16

How would you describe the nuclei in keratinocytes in the stratum spinosum?

Answer 16

Euchromatic nucleus producing a lot of protein

Question 17

Describe the outer cell body of the stratum spinosum.

Answer 17

prickly or spiny

Question 18

What characterizes the stratum granulosum? (4)

Answer 18

• squamous
• Only 3-5 layers of cells
• Cells develop a lipid envelope
• Cytoplasm has basophilic masses

Question 19

How does profilaggrin stain?

Answer 19

intensely blue has a lot of phosphate groups that are very acidic, basophilic and stain blue. Exception to proteins staining pink*

Question 20

Where are the lamellar granules produced and what is their function?

Answer 20

Lipids produced in the cells and are exocytosed to form a layer around the plasma membrane to act as part of the water barrier of skin

Question 21

What is the purpose of filaggrin?

Answer 21

Fillagrin brings keratin and tonofilaments together to condense them.

Question 22

What is keratinization?

Answer 22

The process of binding keratin to filaggrin

Question 23

What characterizes the stratum lucidum? (3)

Answer 23

• see only in thick skin
• cells have lost their nuclei and organelles
• have desmosomes

Question 24

How thick is stratum lucidum?

Answer 24

only a couple cell layers

Question 25

What is the stratum corneum?

Answer 25

Nonnucleated, keratinized cells called squames or cornified cells that have lost their desmosomes and will slough off

Question 26

Having fair skin increases your risk of skin cancer because there is:

Answer 26

Less melanin in keratinocytes

Question 27

How do melanocytes stain?

Answer 27

Stains much clearer around the nucleus than other basal cell layers

Question 28

How do melanocytes orient themselves in the keratinocyte?

Answer 28

In the supranuclear cap to protect DNA from UV radiation

Question 29

Where are Langerhans cells and how do they stain?

Answer 29

Stratum spinosum and stain brown

Question 30

What do langerhans cells do?

Answer 30

They are immune cells that phagocytize antigens. They exit the skin and move to lymph nodes.

Question 31

What can you find in the dermis of the skin? (6)

Answer 31

- blood vessels - connective tissue - hair - sebaceous and sweat glands - sensory receptors

Question 32

What is the purpose of the epidermal ridges and dermal papilla?

Answer 32

Strength- to reinforce the dermal- epidermal junction. The dermal layer provides nutrients for the epidermis.

Question 33

What are the two layers of the dermis?

Answer 33

- papillary layer (top) | - reticular layer

Question 34

What type of collagen is found in the derms?

Answer 34

Type 1- lots in the reticular layer

Question 35

How does the papillary and reticular layers differ?

Answer 35

- More fine collagen, elastin fibers, and more cells in papillary layer. - Course collagen, elastin, less cells in reticular

Question 36

a 34 year old female is stung by a bee, she develops hives and itchiness. What is going on in the skin to cause this reaction?

Answer 36

Mast cells degranulate and release histamine

Question 37

What will cause the itching?

Answer 37

Free nerve endings

Question 38

What do the free nerve endings sense?

Answer 38

Itch, light touch, temperature

Question 39

What is the merkel disc?

Answer 39

The end of the process of an axon.

Question 40

What do merkel discs sense?

Answer 40

light touch

Question 41

What does the root hair plexus sense?

Answer 41

movement of hair

Question 42

What type of structures are the merkel discs, free nerve endings and root hair plexuses?

Answer 42

Simple nerve endings without a cover

Question 43

What is a meissner corpuscle?

Answer 43

Unmyelinated nerve ending surrounded by modified schwann cells and capsule that is adjacent to epithelial cells.

Question 44

Where are Meissner corpuscles found?

Answer 44

Concentrated in the finger tips, hands, soles of feet, lips, and tongue. No hair on this skin. Senses light touch.

Question 45

What is a Pacinian corpuscle?

Answer 45

An axon surrounded by layers of modified Schwann cells and outer CT capsule that may be near adipocytes.

Question 46

Where are Pacinian corpuscle's found?

Answer 46

Either deep in the dermis or the hypodermis

Question 47

What type of touch would Pacinian corpuscles sense?

Answer 47

Course touch, pressure and vibrations

Question 48

What is the shaft of hair?

Answer 48

The portion you can see

Question 49

What is the root of hair?

Answer 49

The portion within the skin

Question 50

What is the hair bulb?

Answer 50

The base of the hair follicle

Question 51

That kind of tissue is hair?

Answer 51

epithelial tissue, located in the dermis but comes from epithelial origin.

Question 52

What makes up the invagination of the epidermis for the hair follicle?

Answer 52

The external root sheath surrounded by the Matrix

Question 53

What muscle attaches to hair?

Answer 53

Arrector pilli muscle

Question 54

What is the dermal papilla?

Answer 54

CT with blood vessels. Damage to the dermal papilla that impairs flood supply can prevent hair growth.

Question 55

What makes up the matrix?

Answer 55

Dividing epithelial cells and melanocytes which give hair its color.

Question 56

How does cells move in hair cells?

Answer 56

Cells move up and are keratinzed to form hair root and then shaft

Question 57

Where do the hair and internal root sheath come from?

Answer 57

Matrix cells

Question 58

What does the external root sheath come from?

Answer 58

Invaginated epidermal cells

Question 59

What is the glassy membrane?

Answer 59

Similar to the basement membrane

Question 60

What surrounds the glassy membrane?

Answer 60

The connective tissue sheath

Question 61

What cells are found in sebaceous glands?

Answer 61

sebocytes

Question 62

Why are the sebocytes not stained?

Answer 62

- Cytoplasm is filled with fat droplets | - sebum is a waxy mix of cholesterol and fats that coat the skin and hair

Question 63

Where do you not find sebaceous glands?

Answer 63

- palms of hands | - soles of feet

Question 64

How is sebum secreted into the hair follicle?

Answer 64

Holocrine secretion

Question 65

Where are eccrine sweat glands found?

Answer 65

All over

Question 66

Where are apocrine sweat glands found?

Answer 66

axillary and perineal regions

Question 67

What are the main characteristics of eccrine sweat glands?

Answer 67

- small lumen - stratified cuboidal epithelium - duct

Question 68

What are the main characteristics of an apocrine sweat gland?

Answer 68

- large lumen - cuboidal epithelium with underlying myoepithelial cells - lumens are fuller and more empty

Question 69

A 14 year old male presents to the emergency department after consuming some jimson weed. His body temperature is elevated and his skin, in general, appears hot and dry. Which is not functioning properly because of the jimsom weed?

Answer 69

Eccrine glands