The Integumentary System

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THE DERMIS
Pages 116-119
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Dermis is made of dense connective tissue
Varies in thickness throughout the body

Has two layers:

◦ Papillary
◦ Reticular


Uneven
Contains projections called dermal papillae
◦ contain capillary loops that furnish nutrients to the
epidermis
◦ houses pain receptors (free nerve endings) and
touch receptors
◦ On hands and feet forms fingerprints:
 Definite patterns that increase friction and gripping
 Sweat pores leave identifying “sweat films”
 Patterns are genetically determined
© 2015 Pearson Education, Inc.


Makes up 80% of dermis
Collagen and elastic fibers
◦ Strength
◦ Elasticity



Blood vessels maintain body temperature
Sweat and oil glands
Lamellar corpuscles- sensory receptors
◦ Send sensory information about deep pressure

(Remember the Merkel cells are responsible for light
pressure and are found in the epiderm-derm jx)
© 2015 Pearson Education, Inc.
Epidermis
Papillary
layer
Dermis
Reticular
layer

Three pigments contribute to skin color:
1. Melanin
 Yellow, reddish brown, or black pigments
2. Carotene
 Orange-yellow pigment from some vegetables
3. Hemoglobin
 Red coloring from blood cells in dermal capillaries
 Oxygen content determines the extent of red coloring
© 2015 Pearson Education, Inc.




Redness (erythema)—due to embarrassment,
inflammation, hypertension, fever, or allergy
Pallor (blanching)—due to emotional stress (such
as fear), anemia, low blood pressure, impaired
blood flow to an area
Jaundice (yellowing)—liver disorder
Bruises (black and blue marks)—hematomas (blood
clots)
© 2015 Pearson Education, Inc.
Hair shaft
Dermal papillae
Epidermis
Papillary
layer
Dermis
Pore
Appendages of skin
• Eccrine sweat gland
• Arrector pili muscle
• Sebaceous (oil) gland
• Hair follicle
• Hair root
Reticular
layer
Hypodermis
(subcutaneous
tissue)
Nervous structures
• Sensory nerve fiber
• Lamellar corpuscle
• Hair follicle receptor
(root hair plexus)
Cutaneous vascular plexus
Adipose tissue
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