Integumentary System 22 Bio

Question 1

Integument (skin)

Answer 1

Largest organ of the body. Also includes nails, hair, and glands.
Thickest skin: Palms and soles of feet
Thinnest skin: External genitalia, eyelids, and tympanum of ear

Question 2

Integument primary functions

Answer 2

1) First line of defense: protects us from injury and disease
2) Prevents loss of water (keratin helps waterproof skin)
3) Regs temperature
4) Stimuli reception: Sensory receptors perceive pain, touch, pressure, etc…
5) Vitamin D production: with help of sunlight

Question 3

Integumentary layers

Answer 3

a) Epidermis (ectoderm)
b) Dermis (mesoderm)
c) Hypodermis (subcutaneous fat layer)
The loose connective tissue can vary in amount in the hypodermis.

Question 4

Epidermis

Answer 4

Stratum … C,L,G,S,B

Stratified squamous keratinized epithelium. No blood vessels in the epidermis.

Question 5

Cells in the epidermis

Answer 5

Langerhans: Antigen present cells (dendritic cells)
Melanocytes: produce melanin pigment, protects you from skin cancer and absorbs UV. Residues in stratum basale (germinativum).
Merkel cells: mechanoreceptors ( pressure or distortion)
Keratinocytes: 80% of the epidermis. Produces keratin

Question 6

Stratum Corneum

Answer 6

Surface layer, surrouns layers of flattened, kertain containing dead cells called horny cells or squames

Question 7

Stratum Basal (germinativum)

Answer 7

Melanocytes and Merkel cells. Deepest epidermal layer.
Mitosis is most active, contain stem cells.
Desmosomes bind the cells of this layer together.

Question 8

Dermis

Answer 8

This connective tissue supports the epidermis and binds it to the hypodermis. Hair follicles, sweat glands, sebaceous oil glands, rich in nerves, derived from mesoderm.

Question 9

Sweat glands, sebaceous glands, and hair follicles are

Answer 9

derived from the epidermis, invade the dermis and hypodermis during embryogenesis and stay permanently.

Question 10

In deep dermis are found

Answer 10

a) Ruffini corpuscles: mechanoreceptors that detect stretching and pressure
b) Pacinian corpuscles: mechanoreceptors that perceive touch, pressure, and vibration
c) Meissner’s corpuscles: detect light touch and sensitivity
d) Nociceptors: pain and myelinated nerve endings
e) Thermoreceptors: heat detection

Question 11

Dermis also contains which proteins

Answer 11

Collagen: abundant fibrous protein for strength, triple helix, highly abundant in glycine, contains hydroxy lsine and hydroxyproline
Elastin: fibrous protein that provides elasticity.
Collagen and elastin fibers break down as we age, wrinkling of the skin.
EcM: jelly like substance that consists of polysaccharides and proteins.

Question 12

Hypodermis

Answer 12

Not part of the skin, layer of fat that has blood vessels.

Subcutaneous fat layer

Question 13

Psoriasis

Answer 13

Increase in dividing cells in the stratum basale and stratum spinosum and increase keratin producing cells and thickening of the epidermis.
Lesions are common on the scalp, knees, or anywhere.

Question 14

Warts

Answer 14

Benign epidermal growths cause by infection of keratinocytes by virus. Hyperplasia

Question 15

Hyperplasia

Answer 15

Increase in cell number

Question 16

Metaplasia

Answer 16

Conversion of one cell type to another. e.g. Smoking, you lose cilia and those cells become non ciliated

Question 17

Dysplasia

Answer 17

Size, shape, and alteration in cell components. Pre cancer

Question 18

Anaplasia

Answer 18

Loss of cellular and organization differentiation. Cancer. Size and shape differ pleomorphism.
Dark staining - hyperchromatism

Question 19

Hypertrophy

Answer 19

Increase in cell size. Runners of marathons often have bigger hearts.

Question 20

Atrophy

Answer 20

Decrease in cell or organ size. Inadequate nutrition of the cells.
Thymus shrinks(atrophies) after puberty
Breast and uterus atrophies after menopause