Transcript PowerPoint 04- Integumentary System

The Integumentary System
A. Skin
1. Anatomy
2. Physiology
3. Epidermis
4. Dermis
B. Glands
1. Sebaceous (oil) glands
2. Sudoriferous (sweat) glands
a. Eccrine
b. Apocrine
C. Thermoregulation:
homeostasis of body temperature
Cells
Tissues
Organs
System
Integumentary System- Skin, hair, nails,
glands, and enamel of teeth
Integumentary System
1. epidermis
2. dermis
3. derivatives
_______________
4. hypodermis
Skin Has 7 Functions
1.
2.
3.
4.
5.
6.
7.
regulation of body temperature
protection
sensation
excretion
immunity
blood reservoir
synthesis of vitamin D
Epidermis
1. keratinized stratified squamous
epithelium
2. four main cell types:
a. keratinocytes (90%)
b. melanocytes (about 8%)
c. Langerhans cells (1%)
d. Merkel cells (1%)
Epidermal Layers
1. stratum basale
2. stratum spinosum
3. stratum granulosum
4. stratum lucidum
5. stratum corneum
___________________
keratinizing system
Thick Skin
Keratinizing System
Keratin gives skin a waterproof,
anti-microbial, and abrasion-resistant
barrier
25-30 rows of fat dead cells filled with
keratin
Thick skin only
3-5 rows of clear, dead cells packed
With eleidin-keratin intermediate
3-5 rows-begin producing
keratohyalin
8-10 rows-derived from
Keratinocytes below- receive
Melanin.
Mitotic zone-keratinocyte stem
Cells, melanocytes and Merkel cells.
EPIDERMAL LAYERS (the keratinizing system)
thick skin
exfoliation
cell death
keratin
eleidin
keratinization
stratum corneum
stratum lucidum
stratum granulosum
keratohyalin
stratum spinosum
mitosis
stratum basale
dermis
The House Dust MiteDermatophagoides
Dermis
1. papillary
2. reticular
____________
functions
Loose areolar tissue
Elasticity, Extensibility,
And Thermoregulation
Dense irregular
Skin Glands
Axillary region, pubic, breasts,
Beards in men. Viscous milky
Fluid-no odor
1. Sebaceous (oil) glands
2. Sudoriferous (sweat) glands
a. merocrine (eccrine)
b. apocrine
(eccrine)
Sebum
Secretion
Combines with
Sweat forms
Acid mantle
Most
Common
90% water
Thermoregulation
Protective Functions of the
Epidermis
1.
2.
3.
4.
acid mantle
role of keratin
role of the stratum corneum
role of the stratum granulosum
Thermoregulation
1. homeotherms vs poikilotherms
2. arterio-venous (AV) plexuses
AV
plexus
BODY TEMPERATURE CONTROL
CONTROLLED CONDITION
A stimulus or stress disrupts
homeostasis by causing an increase in
body temperature
negative
feedback
RETURN TO HOMEOSTASIS
Evaporation of sweat from skin removes
body heat, thus lowering body temperature
and mechanism turns off
RECEPTOR
Thermoreceptors in skin and
hypothalamus are activated and send
nerve impulses to the control center
EFFECTORS
1. Increased sweat output
2. blood vessels vasodilate, bringing heat
to body surface
CONTROL CENTER
Hypothalamic control center sends nerve
impulses to sweat glands and skin blood
vessels
end