Integumentary System

Question 1

What does the integumentary system consist of?

Answer 1

Skin, hair, nails, and glands

Question 2

Where is your skin the thickest?

Answer 2

palms of hands and soles of feet. This is where the most wear and tear occur.

Question 3

Where is your skin the thinnest?

Answer 3

External genitalia, eyelids, and tympanum (inner ear)

Question 4

What are the primary functions of skin?

Answer 4

• First line of defense: protects us from injury and disease
• Prevents water loss. (keratin is involved with waterproofing the skin)
• Regulates temperature: think sweating
• Stimuli reception: sensory receptors perceive pain, touch, pressure, etc.
• Vitamin D production, with sunlight

Question 5

What are the layers of skin?

Answer 5

Epidermis (derived from ectoderm)
Dermis (derived from mesoderm)
Hypodermis (subcutaneous fat layer, it’s not really a layer of skin, but a superficial fascia deep to the skin)

Question 6

What is the cell type of the epidermis?

Answer 6

stratified squamous keratinized epithelium

Question 7

What are the characteristics of the epidermis?

Answer 7

• All but the deepest layers are made of dead cells that contain a fibrous protein called keratin.
• No blood vessels are found in the epidermis
• Consists of four types of cells: Langerhans, melanocytes, merkel cells, keratinocytes.

Question 8

What are Langerhans cells?

Answer 8

• Langerhans cells are antigen presenting cells
• Dendritic cells of the skin
• Similar in morphology and function to macrophages

Longhorns present their horns as threats. Langerhans present antigens as threats to T helper cells. Longhorns also have dandruff so they are dendritic. Longhorns like to eat a lot, so they are macrophages

Question 9

What are Melanocytes?

Answer 9

• Melanocytes produce melanin pigment that gives a brown color to skin
• Protects you from skin cancer. Melanin absorbs UV light
• Resides mostly in the Stratum Germinativum (Stratum Basale)

Question 10

What are the layers of the epidermis from top to bottom?

Answer 10

The layers of the epidermis with the important info needed for the DAT

• Stratum Corneum - Surrounds layers of flattened, keratin containing dead cells called horny cells or squames
• Stratum Lucidum - Only present in thick skin
• Stratum Granulosum
• Stratum Spinosum
• Stratum Basale (Stratum Germinativum)
• Deepest epidermal layer.
• Mitosis is most active - contains stem cells, keratinocytes do mitosis at night, and new cells are being pushed upward toward the surface.
• NB: Melanocytes and Merkel cells are located here
• Desmosomes bind this layer of skin together allowing it to function as a single unit.

Pneumonic: From superficial to deep: Corn lovers grow several bales

Question 11

What are Merkel Cells

Answer 11

Function as mechanoreceptors (a sensory receptor that responds to pressure or distortion)

• Angela Merkel responds to Trumps distortion and pressure

Question 12

What are Keratinocytes?

Answer 12

• 80% of the cell population of the epidermis
• Produce keratin. This waterproofs the skin and protects it from damage. The skin has a lot of desmosomes (cell staples with keratin)

Question 13

Where is keratin found in nature?

Answer 13

• Turtle shells
• Claws of reptiles
• nails
• horns
• shells
• feathers
• beaks

Question 14

Describe the Dermis

Answer 14

Contains:

• Hair Follicles
• Sweat Glands
• Sebaceous (oil) glands
• Rich supply of nerves and muscles

Derived from the mesoderm, unlike the epidermis which was derived from the ectoderm

Question 15

What’s unique about the derivation of some dermis residents?

Answer 15

Sweat glands, sebacecous glands, and hair follicles are all derived in the epidermis and then migrate into the dermis and hypodermis during embryogenesis and then reside there permanently.

Question 16

What are the receptors found in the deep dermis

Answer 16

• Ruffini corpsucles
• Pacinian corpsucles
• Meissner’s corpsucles
• Nociceptors
• Thermoreceptors

Question 17

What are Ruffini corpsucles?

Answer 17

Ruffini corpsucles are mechanoreceptors that detect stretching and pressure

Pneumonic: Stretching is Ruff ini?

Question 18

What are Pacinian corpsucles?

Answer 18

Pacinian corpsucles are mechanoreceptors that perceive touch, pressure, and vibrations

Al Pacino creates corpses through touching his machine gun trigger while feeling the pressure and vibration of the machine gun.

Question 19

What are Meissner’s corpsucles?

Answer 19

Meissner corpsucles detect light touch and sensitivity.

Reinhold Messner froze off all his skin, so he can’t detect light touch and sensitivity anymore.

Question 20

What are Nociceptors?

Answer 20

Nociceptors are pain receptors

These are myelinated nerve endings that branch freely through the dermis

You yell NO! when you’re in pain

Question 21

What are thermoreceptors?

Answer 21

Heat detection. Hot vs Cold

Question 22

What are the structural elements of the dermis?

Answer 22

• Collagen
• Elastin
• Extracellular Matrix

Question 23

What is Collagen?

Answer 23

• Most abundant fibrous protein which provides strength
• Has a triple helix
• Highly abundant in glycine
• Contains hydroxy lysine and hydroxyproline (Vitamin C hydroxylates proline and lysine)
• Every third position is occupied by glycine
• Breaks down as we age causing wrinkles

Question 24

What is Elastin?

Answer 24

• A fibrous protein that provides elasticity

Question 25

What is the extracellular matrix?

Answer 25

- A jelly like substance that consists of polysaccharides and proteins.

Question 26

What is the hypodermis?

Answer 26

- The hypodermis is not a layer of skin, but rather what's directly under the skin. - It contains blood vessels - It's also called the subcutaneous fat layer

Question 27

Tattooing

Answer 27

This is the insertion of pigment into the dermis. An inflammatory response occurs and macrophages will try to get rid of the pigment, but they will fail. Some may end up in the lymph nodes, carried by the macrophages, but the vast majority of the pigment will stay.

Question 28

Psoriasis

Answer 28

An increase in the dividing cells in the stratum basale and stratum spinosum and an accelerated cell cycle results in an increase in keratin-producing cells and a thickening of the epidermis. Lesions are common.

Question 29

Warts

Answer 29

Benign epidermal growths caused by infection of the keratinocytes by a virus. This is an example of hyperplasia (increase of cell number)

Question 30

What is hyperplasia?

Answer 30

Hyperplasia is an increase in cell number -ex: Warts Hyper: A Lot Plasia: Formation (especially referring to cells)

Question 31

What is metaplasia?

Answer 31

Metaplasia is the conversion of one cell type into another. Ex: If you smoke you lose the cilia on your ciliated cells. The cells become non-ciliated cells. This can be reversible Meta: Lots of definitions, but changing is one. Like in metamorphosis Plasia: Formation (especially referring to cells)

Question 32

What is dysplasia?

Answer 32

Dysplasia is size, shape, and alteration of the cell components. Think of it as pre-cancerous Dys: bad Plasia: Formation

Question 33

What is Anaplasia?

Answer 33

Anaplasia is the loss of cellular and organization differentiation. - Usually cancerous - These cells vary in size and shape, we call this pleomorphism Ana: Moving backward Plasia: Formation

Question 34

What is pleomorphism?

Answer 34

The occurrence of more than one natural form. ex: cancerous cells may have a ton of different sizes and shapes within a tumor. pleo: More Morph: Forms

Question 35

What is hyperchromatism

Answer 35

Very dark staining nuclei. Tons of mitotic figures... Weird abnormal cells.

Question 36

Hypertrophy

Answer 36

An increase in the cell size of a tissue or organ. Runners of marathons often have larger hearts

Question 37

Atrophy

Answer 37

Decrease in cell or organ size Usually caused by inadequate nutrition of cells Thymus shrinks after puberty Ovaries and breasts shrink after menopause