Test 2: Integumentary System

Question 1

Structures that make up integumentary system

Answer 1

Skin and accessory structures

Question 2

Epidermis purpose

Answer 2

Protects from trauma, chemicals
Controls permeability, water loss
Protection from pathogens
Synthesizes vitamin D
Sensory receptors
Coordinates immune responses

Question 3

Dermis layers, functions

Answer 3

Papillary layer
Nourishes and supports epidermis

Reticular layer
Restricts spread of pathogens
Stores lipid reserves
Attaches skin to deeper tissues
Sensory receptors of touch, pressure, pain, vibration, temperature
Vessels for thermoregulation

Question 4

Epidermis, general features

Answer 4

Superficial layer
Purple under stain
negatively charged, dermis is positively charged and pink
Keratinized stratified squamous epithelium
Together with dermis make up cutaneous membrane
Avascular

Question 5

Layers of the epidermis

Answer 5

Thick vs thin skin
Thin skin has 4 layers vs 5 of thick skin
fewer cells
hands, lips are thick skin

Stratum corneum
Keratin layer, dead keratinocytes (no nuclei)

Stratum lucidum
Only found in thick skin

Stratum granulosum
Grainy appearance, where pigments are located

Stratum spinosum
Largest layer
hairs connecting cells look spine

Stratum basale
deepest layer
stem cells

Question 6

4 Main cells of epidermis

Answer 6

Keratinocytes
Most abundant, large amounts of keratin

Melanocytes
Specialized cells of stratum basale
Pigment- melanin
Everyone has the same number but the production level is different
Absorbs UV
3% of cells in skin

Langerhans cells
Immune function, develop in bone marrow
Macrophages of the skin

Merkel cells
Specialized cells of stratum basale
1% of cells in skin
Found in hairless skin on merkel discs
Sense pressure

Question 7

Dermis, types of fibers

Answer 7

Collagen fibers
Very strong, resist stretching, provide flexibility

Elastic fibers
Permit stretching, recoils to original length
Limit the flexibility of collagen fibers to prevent damage to tissue

Question 8

Dermis, layers

Answer 8

Outer papillary layer
areolar and adipose tissue
Smaller capillaries, lymphatics, sensory neurons
Dermal papillae projecting between epidermal ridges

Deep reticular layer
Dense irregular connective tissue and adipose
Larger blood vessels, lymph vessels, nerve fibers

Question 9

Lines of cleavage, dermis

Answer 9

Collagen and elastic fibers are arranged in parallel bundles, result in lines of cleavage
resist force in specific direction
cuts parallel to lines of cleavage heal quicker

Question 10

Hypodermis, features

Answer 10

Made of loose connective tissue
areolar and adipose tissue
Subcutaneous layer
Regulates temperature and store energy
site of subcutaneous injections

Question 11

Types of hair

Answer 11

Lanugo
fine soft hair that covers a newborn
disappears

Vellus
white, thin, on most of body during childhood

Terminal hair
thick, strong, pigmented and fully matured
scalp, pubic region, face

Question 12

Arrector pili

Answer 12

Involuntary smooth muscles causing hairs to stand up

Question 13

Sebaceous glands

Answer 13

Lubricate the hair
Control bacteria

transformed keratinocytes with lots of lipids and oil droplets, coats hair and makes them more waterproof, secretes substances by rupturing

typical (hair) vs sebaceous follicles (skin surface)

Question 14

Stem cells

Answer 14

regenerate skin

Question 15

Feathers

Answer 15

epidermal growths
flight, communication, insulation
veined feathers cover exterior
downed feathers are underneath veined feathers

Question 16

Nails,. pathology

Answer 16

made of matrix, nail plate, nail bed, skin

Lacuna is the moon shaped white part

pathology
absence of lacuna indicates vascular issues or high blood pressure
yellow nails indicates resp disorder, thyroid gland
blue indicates hypoxemia, cyanosis
pitted and distorted indicate psoriasis
concave indicates blood disorder
clubbing of nails indicates hypoxemia
protect fingers and toes, made of dead cells packed with keratin

Question 17

Unguis

Answer 17

nail, claw, fang

Question 18

Horns vs antlers

Answer 18

horns
not parts of skull, although fused to skull
covered in sheath of keratin

antlers can be shead
part of skull, emerge first as cartilage with bony replacing
covered with layer of fluffy skin called velvet

Question 19

Sweat glands

Answer 19

merocrine secretion of watery solution, flush epidermal surface

Question 20

Types of exocrine glands, description

Answer 20

Acocrine
limited distribution, complex composition, influenced by hormones
pinched off portion of cell

Merocrine
widespread, thin secretions, controlled primarily by nervous system
important in thermoregulation and excretion
Secretion through secretory vesicles, intact cell membrane, exocytosis

Holocrine
mature cell dies and becomes secretory product

Question 21

Sensory receptors in skin

Answer 21

Merkel disks connected to merkel cell
Meissner corpuscles sense touch below basal level of epidermis
Pacinian corpuscle sense pressure at dermis
Free nerve endings
Thermoreceptors

Question 22

Repair of skin

Answer 22

1: Blood clot and scab formation
platelets clot blood
mast cells trigger inflammation for wound healing, vasodilation
2: Cellular migration
Epithelial cells form around wound
At dermal layer, fibroblasts secrete ECM (collagen, etc) around would
Macrophages eat bacteria, debris
Forms granulation tissue
3: Epidermis covers granulation tissue
Fibroblasts still secrete more matrix
Macrophages also still work 
4: Epidermis covers scar tissue
scar tissue is built in patterns, weaker

Question 23

Skin and aging

Answer 23

can’t sweat as well
less adipose tissue
not as much blood supply
fewer melanocytes
elderly get sunburn easier