1. HONORS ANATOMY & PHYSIOLOGY CHAPTER 5 HUMAN ANATOMY & PHYSIOLOGY
INTEGUMENTARY SYSTEM
HONORS ANATOMY & PHYSIOLOGY
CHAPTER 5
HUMAN ANATOMY & PHYSIOLOGY

2. Integumentary System
Includes:
Skin
Nails
Hair
Sweat & Oil Glands

3. FUNCTIONS Protection: chemical barriers: skin secretions:
acidic: hostile to most bacteria
some bactericidal
melanin: chemical pigment shield protects DNA from damage by UV rays
physical barrier:
continuity of skin & hardness of keratinized cells
stratum corneum: multiple layers of dead cells (brick) and water-resistantglycolipids (mortar)

4. Substances that Penetrate Skin
lipid-soluble substances: )2, CO2, Vit A,D,E,K
oleoresins: poison ivy, poison oak
organic solvents: acetone, dry-cleaning fluid, paint thinner all dissolve cell lipids
heavy metal salts: Pb, Hg
selected drugs: nitroglycerine, nicotine, fentanyl, seasickness meds, estrogen
penetration enhancers: help carry other drugs into body thru skin

5. Functions – Protection cont’d
3. Biological Barriers:
dendritic cells of epidermis
active elements of immune system
agn presenting cells
dermal macrophages
phagocytes  viruses or bacteria
DNA
e- can absorb some UV rays  heat

6. Functions of Skin -2 body temperature homeostasis
when body overheated blood flow to skin increases & some heat radiates off body, sweating (sensible losses)
when body cold less blood flows to skin, more to trunk, goose bumps
@normal temps sweat glands lose ~500 mL/dthru insensible losses

8. Functions of Skin - 3 Cutaneous Sensation (sensory receptors):
exteroceptors: sense stimuli from outside body
Meissner’s corpuscles: in dermal papilla, feel light touch
Pacinian corpuscles: deep dermis or hypodermis, feel deep touch
hair follicle receptors: feel breezes, insect
free nerve endings: pain from irritants or extreme cold or heat

10. Functions of Skin - 4 Metabolic Functions:
Sun light nrg powers some chemical reactions:
modified cholesterol Vit D precursor
keratinocyte enzymes
“disarm” cancer-causing chemicals
activate some steroid hormones (cortisone cream  cortisol a more potent anti-inflammatory)
synthesize important proteins
collagenase

12. Functions of Skin - 5 dermal vessels can hold up to 5%of blood vol.
Blood Reservoir
dermal vessels can hold up to 5%of blood vol.
vessels constricted when
other organs need extra blood
constriction shunts blood to areas in need

14. Functions of Skin- 6 excretory function:
sweat contains urea, uric acid (breakdown products of proteins)
NaCl + water lost with profuse sweating

15. Structure of the Skin
made of 2 kinds of tissues
Epidermis
Dermis

16. Epidermis Keratinocytes Melanocytes Langerhans Cells
made of stratified squamous epithelium
some keratinized, some not
avascular
Cells:
Keratinocytes
majority of cells
make keratin
Melanocytes
Langerhans Cells
Immune System
aka dendritic cells

17. Cells of the Epidermis

18. Epidermal Layers stratum basale stratum spinosum stratum granulosum
deepest layer
constantly undergoing cell division/ cells pushed upward
stratum spinosum
stratum granulosum
stratum lucidum (only in thick skin)
clear, flatter, more keratin
stratum corneum (cornified = keratinized)
outermost layer/ dead cells thick

19. Layers of Epidermis

21. Thick Skin
areas subject to abrasion
palms
soles
finger tips

22. Thin Skin covers rest of body
thinnest skin (thinner subcutaneous layer)
eyelid: 0.02mm
bridge of nose
ankles
knuckles

24. Melanin pigment produced by melanocytes
(yellow to brown to black)
produced by melanocytes
most are in stratum basale
cells stimulated to make more melanin when skin exposed to sunlight
shields DNA from damaging effects of UV radiation
freckles & moles: seen where melanin concentrated in 1 spot

27. Freckle

28. Dermis
a strong, stretchy envelope that helps to hold the body together
leather is the dermis of whatever animal it was made from
made of dense CT: strong& flexible
rich blood supply
2 regions:
Papillary
Reticular

29. Papillary Layer upper dermis
dermal papillae: uneven projections into lower epidermis that contain:
capillaries
pain receptors
touch receptors: Meissner’sCorpuscles
in thick skin: form ridges (fingerprints) that improve gripping ability
genetically determined

30. Dermal Papillae

32. Dermis: Reticular Layer
deepest skin layer
Contains:
sweat & oil glands, hair follicles, blood vessels
Pacinian corpuscles (deep touch receptors)
many phagocytes
fibers: elastic: give young skin elasticity
collagen: make dermis tough & keeps skin hydrated by binding to water

33. Dermis

34. Striae
extreme stretching of skin  white scars
aka stretch marks

35. Blisters
fluid –filled pocket separating epidermis/dermis

36. Skin Color 3 pigments contribute to skin color: Melanin Carotene
amount & kind (yellow  black)
Carotene
orange – yellow pigment
stratum corneum & subcutaneous layers
Hemoglobin
amount O2 bound to it in RBCs in dermal blood vessels
has greater affect in light skinned people

37. Skin Color in Sickness & in Health
cyanosis: blue hue to skin; due to poorly oxygenated blood
erythema: redness, due to increased blood flow (infection, inflammation); burn, HT, blushing
pallor: paleness, due to emotions, anemia, low BP, decreased blood flow
jaundice: yellow; usually from liver disease (not clearing bilirubin)
hematomas: bruising (bleeding under skin)

39. Appendages of the Skin hair& hair follicles nails sweat glands
derivatives of epidermis:
hair& hair follicles
nails
sweat glands
sebaceous glands

40. Hair & Hair Follicles palms soles lips nipples
areas of skin with no hair:
palms
soles
lips
nipples
parts of external genitalia

41. Functions of Hair sense insects b/4 they bite
protects against heat loss (scalp)
protects against sun
shield eyes
filter air inhaled through nose

42. Hair tougher & more durable individual cells do not flake off “pili”
produced by hair follicles
consist of dead keratinized cells
keratin here compared to keratin in epidermis:
tougher & more durable
individual cells do not flake off

44. Hair 3 concentric layers of keratinized cells Medulla Cortex Cuticle
innermost
large cells & air space
absent in fine hair
Cortex
surrounds medulla
layers of flattened cells
Cuticle
1 layer overlapping cells
provides strength

46. Hair Pigment melanocytes @ base of follicle  to cortical cells
differing proportions of melanins of different colors give different hair colors
melanin production decreases (delayed-action genes)  replaced by air bubbles  gray  white

47. Hair Follicle fold down from epidermis  dermis forming hair bulb
sensory nerve ending : root hair plexus surrounds hair bulb
bending hair stimulates plexus
sensitive touch receptors

48. Hair Follicle
dermal papilla: bit of dermal tissue protruding into base of follicle
capillaries
matrix: actively dividing cells produces hair
arrector pili: smooth muscle from dermal part of follicle  angle
contraction  goose bumps

50. Types of Hair pale, fine hair children and females coarse long hairs
VELLUS
TERMINAL
pale, fine hair
children and females
coarse long hairs
eyebrows, scalp
@ puberty:

51. Factors the Influence Hair Growth
Nutrition
poor nutrition  poor growth
Hormones
local inflammation  increased growth
normal growth~2.5 mm/wk
fastest growth teens  40’s then slows
each follicle goes thru cycle:
active growth phase
wks  yrs
regressive phase
matrix cells die
resting phase
1 – 3 mos

52. Hirsutism excessive hairiness
could be from ovarian or adrenal gland tumor secreting high levels of androgens

53. Alopecia hair thinning starts @ anterior hairline  posteriorly males:
by age 35: 40%
by age 60: 85%

54. Male Pattern Baldness most common type of baldness
X-linked recessive inheritance:
delayed-action gene switches on in adult & changes hair follicle response to testosterone  follicles very short growth cycle  may get vellus hair

55. Alopecia Areata immune system attacks hair follicles
hair falls out in patches

57. Nails scalelike modification of epidermis hard keratin Functions:
forming clear protective covering on dorsal surface of distal digits
hard keratin
Functions:
pick up small objects
scratch
protect tips of digits

58. Parts of a Nail free edge nail plate or body nail bed proximal root
proximal portion = matrix: nail growth
proximal root
nail folds:
proximally :eponychium (cuticle)

59. Nail Abnormalities yellow: thyroid or respiratory problem
thickened yellow: fungus infection
outward concavity: iron deficiency (spoon nail)
horizontal lines: malnutrition

60. Sweat Glands aka sudoriferous glands over entire skin surface except:
nipples
parts of external genitalia
2 types:
Eccrine Sweat Glands
Apocrine Sweat Glands
secretory cells surrounded by myoepithelial cells: contract when stimulated by nervous system  sweat goes thru duct to skin

61. Eccrine Sweat Glands more numerous than apocrine
abundant on palms & soles of feet
secretory cells in dermis
sweat released thru pore (not skin pore)

62. Eccrine Sweat Gland secretion: hypotonic (99% water) filtrate of blood
also has:
salts
vitamin C
abys
wastes: urea, uric acid, NH3

63. Eccrine Sweat Gland regulated by sympathetic division of ANS
Functions:
prevent overheating
forehead  spreads inferiorly
“emotional” sweating
fright or extreme nervousness
palms, soles, or axilla  over body

64. Apocrine SweatGlands axillary & anogenital areas only
larger than eccrine glands
found deeper in dermis/hypoderrmis
empty onto hair follicle
odorless until released onto skinwhere bacteria decompose molecules  musky, unpleasant odor
in addition to what is found in eccrine sweat:
fatty acids
proteins

65. Apocrine Sweat Glands begin functioning @ puberty
activated by sympathetic division of ANS during:
pain
stress
exact function uncertain but likely analogous to animals glands that secrete pheromones

67. Ceruminous Glands modified apocrine glands
secretion mixes with sebum (made by sebaceous gland)  cerumen (ear wax)
Function:
deters insects
blocks entry of foreign objects

68. Mammary Glands
specialized sweat glands that secrete milk

69. Sebaceous Glands oil glands found with hair follicles
smaller on trunk & limbs
large on face, neck, upper chest
secrete sebum: oily substance
develop as outgrowths of hair follicle
arrector pili contractions force sebum to skin surface
androgens stimulate secretion (activity starts in puberty)

71. Sebum
Functions:
softens & lubricates skin & hair
bactericidal action

72. Whitehead Blackhead created by: sebum in whitehead oxidizes
sebum blocks sebaceous gland duct
sebum in whitehead oxidizes

73. Acne active inflammation of sebaceous glands
see: pustules or cysts on skin surface
associated with bacterial infection (staph)

74. Skin Cancer Benign tumors such as warts and moles are not serious.
Malignant tumors can start on the skin and invade other body areas.
Crucial risk factor- overexposure to UV radiation

75. Skin Cancer 20% in USA will develop skin cancer (↑ing #s)
#1 risk factor: Sun UV radiation
DNA damaged
suppresses tumor suppressor gene
new skin lotions contain liposomes  initiate repairof damaged DNA

76. Types of Skin Cancer
Basal cell carcinoma- most common, 30% of all white skin people get it.
Arises from the stratum basale layer of the skin
99% curable if caught early
Dome shaped nodules that form an ulcer in the center.
Squamous Cell carcinoma-
Arise from stratum spinosum
Grows rapidly and metastasizes if not removed
Small red rounded elevation on the skin

77. Basal Cell Carcinoma

78. Lesion removed from patient
Basal Cell Carcinoma

79. Squamous cell carcinoma

80. Skin Cancer Types cont. Melanoma
Cancer of melanocytes (very dangerous)
5% of skin cancers but rising fast
Can arise from preexisting moles
Appears as a spreading brown or black patch
Chance of survival is poor if the lesion is greater than 4 mm thick

81. Melanoma

84. What is the ABCD rule? Used for recognizing melanoma
A-Asymmetry: two sides of the pigmented mole do not match
B-Border irregularity: borders are not smooth
C- Color: lesion has a multiple of colors
D- Diameter the spot is larger than 6 mm in diameter (size of a pencil eraser)

85. What are the 3 types of burns?
First-degree burns: only the epidermis is damaged. Redness, swelling and pain are common. (sunburn) 2-3 days to heal
Second-degree burns: epidermis and upper layers of dermis. Blistering can occur. 3-4 weeks to heal.
Third-degree burns: involves the entire thickness of the skin. (pg )

86. Second-degree burns
Third-degree burn

87. Burn Evaluation Rule of 9’s:
divides body into11areas each 9% of body surface area + 1% for genitalia

89. Burn Treatment
patients require extra calories to replace lost proteins & allow tissue repair
must add parenteral nutrition (IV)
2◦ infections main threat
24 hrs after burn wound is sterile
fungi, bacteria,& other pathogens multiply rapidly
Immune system deficient
infection leading cause of death in burn victims

90. Burn Treatment: Skin Grafts
1st debride burned tissue
wash area with antibiotic in solution
apply synthetic membrane temporarily
skin graft: healthy skin applied to area
autograft: taken from the patient
synthetic skin: silicone “epidermis” bound to spongy “dermis” made of collagen fibers & ground cartilage  patients own cells absorb &replace synthetic
* no rejection from immune system

91. Think About It