Skin, Wound Healing And Reflexes LO

Question 1

List the structures of the skin

Answer 1

• hair shaft
• stratum corneum
• germination layer
• dermal papilla
• Meissners corpuscle
• sebaceous gland
• arrector pili muscle
• hair root
• hair follicle
• hair papilla
• cutaneous nerve

Question 2

Describe the 5 layers of the skin

Answer 2

1) Stratum basale
- deepest layer
- attaches epidermis to basale laminate
- below lies the dermis
- bonding via intertwining collagen fibres
- finger like folds called dermal papilla found in superficial part
- has merkel cells
2) stratum spinosum
- provides strength and flexibility
- 8-10 layers of keratinocytes
- Release water repelling glycolipid
- keratinocytes moved into stratum granulosum
- dendritic cells and langerhans cells
3) stratum granulosum
- represents transition between deeper metabolically active strata and the dead cells of superficial strata
- 3-5 layers of flat dying cells
- show nuclear degeneration
- contains lamellar granules that release water repellent lipids
- dark staining keratinocyte granules
- keratinohyalin converts tonofilaments into keratin
- give it its grainy apperance
4) stratum lucidium
- smooth
- translucent layer
- on palms and soles of feet
- keratinocyte are dead and flattened
- packed with eledin - protein rich with lipids
- contains precursor to keratin
5) Stratum corneum
- most superficial layer
- 25-30 layers of keratinocytes
- provides mechanical and protective layer against abrasion
- regular bedding of cells that are pushed up

Question 3

Describe the functions of the skin

Answer 3

1) protection
2) regulation of body temperature - sweat glands
Eccrine - open, watery substance, not fully active in infants, present on palms, soles of feet, achillea and groins
Apocrine - sweat glands develop during puberty and secrete alongside hair follicles, mix with bacteria of skin = body odour
Sebaceous glands - secrete onto hair follicles, scalp, face, axillae and groin. Waterproof,barrier, bacterial and fungicidal, prevents cracking and drying of exposure to heat and sunlight. Less active in elderly and infants
3) formation of vitamin D
4) cutaneous sensation
5) excretion
6) absorption
7) movement and growth

Question 4

Understand the principles of wound healing

Answer 4

Inflammation - within first few hours wound surfaces become inflamed, a blood clot (mainly fibrin) and cell debris fill the gap between them
Proliferation - epithelial cells proliferate across the wound. The clot above the new tissue becomes the scab, which separates after 3-10 days
Maturation - the granulation tissue is gradually replaced by fibrous scar tissue. Rearrangement of collagen fibres occurs and the strength of the wound increases. In time the scar becomes less vascular. During fibrosis scar tissue replaces granulation tissue usually over several moths until full thickness of the skin is restored

Question 5

Identify normal reflexes present in adults

Answer 5

Pupillary reflex - used to assess brain trauma + deterioration of brain tissue. Normally pupils round and equal size
Upper limb circuits - biceps (C6/6), triceps (C6/7), supination - aka brachioradialisis (C5/6)
Lever limb circuits - knee (L3/5), ankle (L5/S1)
Knee jerk reflex (patella tendon) - assess nerves between region of spinal cord between lumbar 2+4. Elicited by sharply tapping just below the knee with the base of a Taylor hammer
Ankle jerk reflex (calcaneal) - stretch reflex, assess nerves between first two sacral segments. Elicited by tapping just above the ankle with base of a taylor hammer
Planter reflex - superficial spinal reflex. Elicited by firmly drawing the handle of a Taylor hammer along the lateral border of foot from heel to toe. In adults - toes reflex moves together

Question 6

Identify normal infant reflexes

Answer 6

• At birth reflexes are primitive - no control over voluntary movement
• Primitive reflexes present at birth indicate status if CNS
• Primitive reflexes superseded by postural reflexes as infant matures in first 6-12 months of life
  Babinski, blinking, gag, grasping, Moro (startle)

Question 7

Understand how nurses can identify reflexes

Answer 7

Use a Taylor hammer
Check for normal response

Question 8

Explore changes in skin from preterm to old age

Answer 8

In infants the stratum corneum is thinner so appears smoother and softer.
In the elder their skin is thinner and loses fat so no longer looks as plump and smooth.