integumentary system exercise # 8 page#73 competency 3: the integumentary system upon successful...
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INTEGUMENTARY SYSTEMExercise # 8
Page#73
Competency 3: The Integumentary System
• Upon successful completion of this laboratory, the students should be able to recognize the various skin components of the integumentary system by:
– Recognizing, from prepared slides, selected skin tissues and structures.
– Explaining the structures and functions of epidermal and dermal layers of skin.
– Identifying the major parts of the hair.
INTEGUMENTARY SYSTEM(Martini, chapter 5)
• LAYERS OF THE SKIN• FROM EXTERNAL TO INTERNAL:
• 1- EPIDERMIS• 2- DERMIS• 3- HYPODERMIS
ALFONSO A. PINO MD.
EPIDERMIS• Function- protection from chemical, physical & biological agents
• 5 stratum (from external to internal)• Stratum corneum• Stratum lucidum• Stratum granulosum• Stratum spinosum• Stratum germinativum (basale)
• Stratum corneum- 15-30 layers of keratinized cells. Water • resistant F- allows insensible perspiration More or less 500 ml of water every day• Stratum lucidum- clear layer only in thick skin (palms & soles). F-contains flattered & packed cells filled with the protein
keratin• Stratum granulosum- grainy layer F- to produce protein keratin & keratohyalin basic structural component of hair & nails
• Stratum spinosum (8 to 10 layers) F- it contains Langerhands cells for Immune response against microorganisms & Cancer cells • Stratum germinativum or basale (The innermost) F- cells divide to replace superficial cells
it contains Melanocytes –to produce melanin For protection against uv radiation
ALFONSO A. PINO MD.
Epidermis (5 stratums)
DERMIS
• Function- thermoregulation & protection 2 mayor components- papillary & reticular layers
• Papillary - contains capillary & lymphatic vessels & sensory neurons function- support & nourishment of the overlaying epidermis
• Reticular - deep to papillary layer function- to resist tension in the skin
HYPODERMIS
• FUNCTION- ENERGY STORE CUSHIONING INSULATION
ACCESSORY STRUCTURES• Meissner’s corpuscles (white in models) F- light touch & tactile receptors• Pacinian corpuscles (olive in models) F- deep pressure & vibration receptors• Sebaceous glands- discharges waxy
sebum into the hair •
follicle F- lubrication• Hair: for protection, insulation, and tactile
reception. It is divided into: Shaft: exposed hair and first part under skin Root- surrounded by hair follicle. Contains
hair papilla- at the base Hair bulb- surrounds the papilla• Arrector pili- smooth muscle that erects the
hair• Sweat glands- Apocrine Merocrine
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Sebaceous Glands and Sweat Glands• Exocrine Glands in Skin
– Sebaceous glands (oil glands)
• Holocrine glands
• Secrete sebum
– Sweat glands
• Two types: apocrine glands and merocrine (eccrine) glands• Merocrine – products are secreted by exocytosis (e.g., pancreas, sweat, and salivary glands)• Apocrine-- producing a fluid secretion by pinching off one end of the secretory cell while leaving the rest intact.• Holocrine – products are secreted by the rupture of gland cells (e.g., sebaceous glands)• Watery secretions
ALFONSO A. PINO MD.
Hair follicle
ALFONSO A. PINO MD.
Hair follicle
Nails
• Nails
• protect fingers and toes
– Made of dead cells packed
with keratin
– Metabolic disorders can
change nail structure
• Nail production
– Occurs in a deep epidermal
fold near the bone called
the nail root
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Nails• Structure of a Nail
– Nail body• The visible portion of the nail• Covers the nail bed
– Lunula• The pale crescent at the base of the nail
– Sides of nails• Lie in lateral nail grooves • Surrounded by lateral nail folds
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Nails• Structure of a Nail
– Skin beneath the distal free edge of the nail
• Is the hyponychium (onyx = nail)
– Visible nail emerges
• From the eponychium (cuticle)
• At the tip of the proximal nail fold
REMEMBER, GO TO THE TUTORING ROOM AND PRACTICE WITH MODELS!
ROOM 3326