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Integumentary System
Exploring the largest organ system, the Skin
REVIEW
Complete the following Tables
REVIEW
Objectives
Name the tissue in the epidermis and dermis
List the layers of the epidermis and describe the function of the main cell types
Describe the structure and the function of the two layers of the dermis
Describe the origin and function of sweat and sebum
OBJECTIVES
Describe the role of the Ingetumentary system - body temperature regulation, cutaneous sensation, and blood circulation
THE SKIN
Covers entire body - 1.5 - 2 m2
6-8% of total body weight ~ 5 kg
THE SKIN
One square cm skin contains: 500,000 skin cells, 70 blood vessels, 100 sweat glands, 15 oil, and 230 sensory receptors
Colours vary - varying amounts of pigment
Can range from 1/10 mm thick on eyelids to 3-4 mm thick on soles of feet
Structure of Skin
Epidermis
Epidermis Layers
Epidermis Layers
Stratum Corneum
Stratum Granulosum
Stratum Spinosum
Stratum Basale
Epidermis Cells
Epidermis Cells
Keratinocytes
Langerhans Cells
Melanocytes
Merkle Cells
DERMIS
Dermis
Dermis
Layers
Dermis
Layers
Papillary Layer:
~ Areolar connective tissue
~ Blood vessels
~ Dermal papillae, dermal ridges
Reticular Layer:
~ 80% of dermis
~ Dense irregular connecive tissue
~ Sweat and oil glands
~ Sensory receptors
HYPODERMIS
Superficial Fascia
Review
Draw a diagram of the skin - Include:
The five layers of the epidermis
Various types of cells found in epidermis
The two layers of the dermis
Appendages
Sweat Gland
Sweat Gland
Two types:
~ Eccrine
~ Apocrine
Coil of epidermal cells reaching down deep into the dermis
Secrete sweat
Found everywhere especially on palms, soles, and forehead
Sebaceous (oil) Glands
Sebaceous (oil) Glands
Secrete oil (sebum) into hair shaft
Formed from downward extension of epithelial cells into dermis
Oil softens and lubricates skin and hair
Hair (Pili) Follicles
Hair (Pili) Follicles
Site dependent functions:
~ Head: heat loss, protective
~ Nose: filters, large particles
~ Eyelashes: shield the eyes
Sensitive touch
receptors
Dead, keratinized cells
Function as tool to pick up objects or scratch
Nails
Contain hard keratin
Function as tool to pick up objects or scratch
Functions of the Integumentary System
Functions of the Integumentary System
Protection
Metabolic Functions
Blood Reservoir
Cutaneous Sensation