1. Chapter 4 Skin and Body Membranes
Essentials of Human Anatomy & Physiology
Seventh Edition
Elaine N. Marieb
Chapter 4 Skin and Body Membranes
Slides 4.1 – 4.32
Lecture Slides in PowerPoint by Jerry L. Cook
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2. Skin and Body Membranes
Function of body membranes
Line or cover body surfaces
Protect body surfaces
Lubricate body surfaces
YOU NEED TO REMEMBER THESE FUNCTIONS!
Slide 4.1
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3. Classification of Body Membranes
Epithelial membranes
Cutaneous membrane
Mucous membrane
Serous membrane
Connective tissue membranes
There are two types or classifications of body membranes:
Epithelial and Connective.
Epithelial membranes is also broken down into three distinct membranes or mini-organs. We’ll look at each one individually.
Slide 4.2
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4. Cutaneous Membrane Cutaneous membrane = skin Superficial epidermis
A dry membrane
Outermost protective boundary
Superficial epidermis
Keratinized stratified squamous epithelium
Underlying dermis
Mostly dense connective tissue
The cutaneous membrane is a dry membrane because it is exposed to air.
Keratinocytes are cells rich in proteins that give our skin its toughness.
Figure 4.1a
Slide 4.3
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5. Mucous Membranes Surface epithelium
Type depends on site
Underlying loose connective tissue (lamina propria)
Lines all body cavities that open to the exterior body surface
Often adapted for absorption or secretion
HIGHLIGHT – Lines all body cavities that open to the exterior body surface.
These membranes also line the hollow organs of the respiratory, digestive, urinary, and reproductive tracts.
While most of these membranes secrete mucus to protect and lubricate, the urinary membrane does not.
Figure 4.1b
Slide 4.4
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6. Serous Membranes Surface simple squamous epithelium
Underlying areolar connective tissue
Lines body cavities that are closed to the exterior of the body
Serous layers separated by serous fluid
HIGHLIGHT – Lines body cavities that are closed to the exterior of the body.
This membrane is a paired membrane. This single membrane folds in on itself and gives rise to being paired.
One layer lines the cavity (parietal) and the second layer lines the organ it protects (visceral).
These serous layers are separated by a thin clear fluid called serous fluid.
Figure 4.1c
Slide 4.5
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7. Serous Membranes Specific serous membranes Peritoneum Pleura
Abdominal cavity
Pleura
Around the lungs
Pericardium
Around the heart
HIGHLIGHT these specific serous membranes.
Figure 4.1d
Slide 4.6
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8. Connective Tissue Membrane
Synovial membrane
Connective tissue only
Lines fibrous capsules surrounding joints
Synovial membranes are composed of soft areolar connective tissue and contain no epithelial cells at all.
Figure 4.2
Slide 4.7
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9. Integumentary System Skin (cutaneous membrane) Skin derivatives
Sweat glands
Oil glands
Hairs
Nails
The central function of the skin and its derivatives is protection. Protection of the the body and its internal organs and systems.
Slide 4.8
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10. Skin Functions Protects deeper tissues from: Mechanical damage
Chemical damage
Bacterial damage
Thermal damage
Ultraviolet radiation
Desiccation
The first, and again central, function of the skin is protection.
Mechanical damage refers to the bumps and cuts.
Chemical damage refers to things like acids and bases we come in contact with.
Slide 4.9a
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11. Skin Functions Aids in heat regulation
Aids in excretion of urea and uric acid
Synthesizes vitamin D
Three additional functions of the skin include…
HIGHLIGHT – that the skin also manufactures vitamin D.
Along with making vitamin D, the skin also makes several proteins important to our immunity.
Slide 4.9b
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12. Skin Structure Epidermis – outer layer Stratified squamous epithelium
Often keratinized (hardened by keratin)
Dermis
Dense connective tissue
HIGHLIGHT – that the epidermis (outer layer) is made of stratified squamous epithelium.
Slide 4.10a
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13. Skin Structure Deep to dermis is the hypodermis Not part of the skin
Anchors skin to underlying organs
Composed mostly of adipose tissue
The primary function of the hypodermis is to serve as a shock absorber and insulate the deeper tissues from extreme temperature changes.
Slide 4.10b
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14. Layer of Epidermis Stratum basale Stratum spinosum Stratum granulosum
Cells undergoing mitosis
Lies next to dermis
Stratum spinosum
Stratum granulosum
Remember that the epidermis is avascular.
The stratum basale is the closest layer to the dermis and receives nourishment by diffusion from the dermis.
The stratum basale is the layer that divides and produces new skin cells. A.K.A. Stratum germinativum.
The epithelial cells become fully keratinized following the stratum granulosum.
Slide 4.11a
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15. Layer of Epidermis Stratum lucidum Stratum corneum
Occurs only in thick skin
Stratum corneum
Shingle-like dead cells
The stratum lucidum will always be found on the palms and soles of the feet.
The stratum corneum is the outermost layer of skin and is cell layers thick.
The stratum corneum is the layer that protects the deeper cells from the external environment and from water loss.
You have a new epidermis every 25 to 45 days.
Slide 4.11b
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16. Melanin Pigment (melanin) produced by melanocytes
Color is yellow to brown to black
Melanocytes are mostly in the stratum basale
Amount of melanin produced depends upon genetic and exposure to sunlight
HIGHLIGHT – Melanocytes are mostly in the stratum basale.
Freckles and moles are where melanin is concentrated in one spot.
Melanin concentrates on the sunny side of the nuclei to protect them from the damaging effects of the UV rays.
Slide 4.12
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17. Dermis Two layers Papillary layer Reticular layer
Projections called dermal papillae
Pain receptors
Capillary loops
Reticular layer
Blood vessels
Glands
Nerve receptors
Papillary layer is the upper layer and contains the dermal papillae.
The papillae are also arranged in patterns that form looped and whorled ridges on the epidermal surface that increase friction and enhance the gripping ability of the fingers and feet – Finger prints
Along with free nerve endings (pain receptors) the papillary layer also has Meissner’s Corpuscles (Touch Receptors).
Reticular layer is the deepest skin layer.
The dermis is filled with blood vessels that play a role in maintaining body temperature homeostasis.
Slide 4.13a
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18. Skin Structure Figure 4.4 Slide 4.13b
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19. Normal Skin Color Determinants
Melanin
Yellow, brown or black pigments
Carotene
Orange-yellow pigment from some vegetables
Hemoglobin
Red coloring from blood cells in dermis capillaries
Oxygen content determines the extent of red coloring
Cyanosis is a condition when the hemoglobin is poorly oxygenated (bluish).
Redness (erythema) caused by: embarrassment, fever, hypertension, inflammation, or allergy.
Pallor (blanching – pale) caused by: anemia, low blood pressure, or impaired blood flow.
Jaundice (yellow cast) caused by: a liver disorder where excess bile pigments are absorbed into the blood.
Bruises (eccymosis) caused by: blood escaping from circulation and clotted in tissue spaces (hematoma). Can also be because of a vitamin c deficiency.
Slide 4.14
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20. Cyanosis

21. Erythema

22. Erythema

23. Jaundice

24. Eccymosis

25. Eccymosis

26. Lyme Disease Rash

27. Scurvy (Vitamin C Deficiency)

29. Stage I

30. Stage II

31. Stage III

32. Stage IV

33. Appendages of the Skin Sebaceous glands Produce oil Lubricant for skin
Kills bacteria
Most with ducts that empty into hair follicles
Glands are activated at puberty
Sebum is the product of the sebaceous glands. It is a mixture of oily substances and fragmented cells.
Sebum is a lubricant that keeps the skin soft and moist and presents the hair from becoming brittle.
When gland get blocked by sebum, a whitehead appears, if it stays and oxidizes a blackhead appears.
Acne is an active infection of the sebaceous glands accompanied by pimples
Slide 4.15
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34. Appendages of the Skin Sweat glands Widely distributed in skin
Two types
Eccrine
Open via duct to pore on skin surface
Apocrine
Ducts empty into hair follicles
Sweat is mostly made of water plus some salts, vitamin C, traces of metabolic wastes such as ammonia, urea, uric acid, and lactic acid (the chemical that attracts mosquitoes).
The ECCRINE sweat glands are supplied with nerve endings that cause them to secrete sweat when the body temp. is high.
The APOCRINE sweat glands are mostly confined to the axillary and genital areas of the body.
Slide 4.16
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35. Sweat and Its Function Composition Function
Mostly water
Some metabolic waste
Fatty acids and proteins (apocrine only)
Function
Helps dissipate excess heat
Excretes waste products
Acidic nature inhibits bacteria growth
Odor is from associated bacteria
Slide 4.17
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36. Appendages of the Skin Hair Produced by hair bulb
Consists of hard keratinized epithelial cells
Melanocytes provide pigment for hair color
Figure 4.7c
Slide 4.18
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37. Hair Anatomy Central medulla Cortex surrounds medulla
Cuticle on outside of cortex
Most heavily keratinized
Figure 4.7b
Slide 4.19
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38. Associated Hair Structures
Hair follicle
Dermal and epidermal sheath surround hair root
Arrector pili
Smooth muscle
Sebaceous gland
Sweat gland
Arrector pili muscles connect each side of the hair follicle to the dermal tissue.
When these muscles contract, the hair is pulled upright, dimpling the skin surface with “goose bumps.”
Figure 4.7a
Slide 4.20
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39. Appendages of the Skin Nails Scale-like modifications of the epidermis
Heavily keratinized
Stratum basale extends beneath the nail bed
Responsible for growth
Lack of pigment makes them colorless
Scale-like modifications of the epidermis that corresponds to the hoof or claw of other animals.
Slide 4.21
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40. Nail Structures Free edge Body Root of nail
Eponychium – proximal nail fold that projects onto the nail body
Figure 4.9
Slide 4.22
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41. Skin Homeostatic Imbalances
Infections
Athletes foot
Caused by fungal infection
Boils and carbuncles
Caused by bacterial infection
Cold sores
Caused by virus
Slide 4.23
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42. Athlete’s Foot

43. Boils and Carbuncles

44. Cold Sore

45. Skin Homeostatic Imbalances
Infections and allergies
Contact dermatitis
Exposures cause allergic reaction
Impetigo
Caused by bacterial infection
Psoriasis
Cause is unknown
Triggered by trauma, infection, stress
Symptoms of Contact Dermatitis include itching, redness, and swelling of the skin. This later progresses to blistering.
Slide 4.24
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46. Contact Dermatitis

47. Impetigo

48. Psoriasis

49. Skin Homeostatic Imbalances
Burns
Tissue damage and cell death caused by heat, electricity, UV radiation, or chemicals
Associated dangers
Dehydration
Electrolyte imbalance
Circulatory shock
Dehydration (loss of proteins and electrolytes) is the major concern in burn patients.
The second major concern is infection. Infection is the leading cause of death in burn patients.
Slide 4.25
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50. Rules of Nines Way to determine the extent of burns
Body is divided into 11 areas for quick estimation
Each area represents about 9%
The reason we determine the extent of burns is because it helps us to indirectly determine how much fluid is lost.
Slide 4.26
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51. Severity of Burns First-degree burns Second degree burns
Only epidermis is damaged
Skin is red and swollen
Second degree burns
Epidermis and upper dermis are damaged
Skin is red with blisters
Third-degree burns
Destroys entire skin layer
Burn is gray-white or black
Slide 4.27
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52. Critical Burns Burns are considered critical if:
Over 25% of body has second degree burns
Over 10% of the body has third degree burns
There are third degree burns of the face, hands, or feet
Slide 4.28
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53. 1st Degree

54. 2nd Degree

55. 3rd Degree

56. Skin Cancer Cancer – abnormal cell mass Two types Benign
Does not spread (encapsulated)
Malignant
Metastasized (moves) to other parts of the body
Skin cancer is the most common type of cancer
Slide 4.29
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57. Skin Cancer Types Basal cell carcinoma Squamous cell carcinoma
Least malignant
Most common type
Arises from statum basale
Squamous cell carcinoma
Arises from stratum spinosum
Metastasizes to lymph nodes
Early removal allows a good chance of cure
Slide 4.30
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58. Skin Cancer Types Malignant melanoma Most deadly of skin cancers
Cancer of melanocytes
Metastasizes rapidly to lymph and blood vessels
Detection uses ABCD rule
Slide 4.31
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59. ABCD Rule A = Asymmetry B = Border irregularity C = Color D = Diameter
Two sides of pigmented mole do not match
B = Border irregularity
Borders of mole are not smooth
C = Color
Different colors in pigmented area
D = Diameter
Spot is larger then 6 mm in diameter
Slide 4.32
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