1. The Integumentary System5
The Integumentary System

2. Consists of three major regions
Skin (Integument)
Consists of three major regions
________________ – outermost superficial region
Dermis – __________________
Hypodermis (superficial fascia) – deepest region

3. Reticular layer of dermis
Hair shaft
Pore
Dermal papillae
(papillary layer
of dermis)
Epidermis
Meissner's corpuscle
Free nerve ending
Reticular layer of dermis
Sebaceous (oil) gland
Dermis
Arrector pili muscle
Sensory nerve fiber
Eccrine sweat gland
Pacinian corpuscle
Hypodermis
(superficial
fascia)
Artery
Vein
Hair root
Adipose tissue
Hair follicle
Eccrine sweat
gland
Hair follicle receptor
(root hair plexus)
Figure 5.1

4. Epidermis
Composed of keratinized ____________ ____________ epithelium, consisting of four distinct cell types and four or five layers
Cell types include ______________, melanocytes, Merkel cells, and ___________________ cells
Outer portion of the skin is exposed to the external environment and functions in protection

5. Cells of the Epidermis
________________ – produce the fibrous protein keratin
________________ – produce the brown pigment melanin
Langerhans’ cells – epidermal macrophages that help activate the immune system
Merkel cells – function as touch receptors in association with sensory nerve endings

6. Layers of the Epidermis
Figure 5.2b

7. Layers of the Epidermis: Stratum Basale (Basal Layer)
Deepest epidermal layer firmly attached to the ____________________
Consists of a single row of ___________________
Cells undergo rapid division, hence its alternate name, stratum ________________

8. Layers of the Epidermis: Stratum Spinosum (Prickly Layer)
Cells contain a weblike system of intermediate filaments attached to _________________
_________________granules and _________________ cells are abundant in this layer

9. Layers of the Epidermis: Stratum Granulosum (Granular Layer)
Thin; three to five cell layers in which drastic changes in ______________________ appearance occurs
Keratohyaline and ___________________ granules accumulate in the cells of this layer

10. Layers of the Epidermis: Stratum Lucidum (Clear Layer)
Thin, transparent band superficial to the stratum __________________
Consists of a few rows of flat, dead keratinocytes
Present only in __________ ___________

11. Layers of the Epidermis: Stratum Corneum (Horny Layer)
Outermost layer of ________________________ cells
Accounts for three quarters of the ______________ thickness
Functions include:
_______________________
Protection from _________________ and penetration
Rendering the body relatively __________________ to biological, chemical, and physical assaults

12. Layers of the Epidermis
Figure 5.2b

13. Dermis
Second major skin region containing strong, flexible _____________ tissue
Cell types include _______________, macrophages, and occasionally mast cells and ______________________________________
Composed of two layers – ______________ and ___________________

14. Layers of the Dermis: Papillary Layer
Areolar connective tissue with _______________ & _________________________________fibers
Its superior surface contains peglike projections called ___________________________________
Dermal papillae contain capillary loops, Meissner’s________________________________ _________________________________________

15. Layers of the Dermis: Reticular Layer
Accounts for approximately _____% of the thickness of the skin
Collagen fibers in this layer add _____________ and _________________________ to the skin
Elastin fibers provide ______________________ properties

16. Hypodermis
_________________________ layer deep to the skin
Composed of _______________ and _________________ connective tissue

17. Three pigments contribute to skin color:
______________________________– yellow to reddish-brown to black pigment, responsible for dark skin colors
______________________________– result from local accumulations of melanin
______________________________ – yellow to orange pigment, most obvious in the ____________ and __________________________
______________________________– reddish pigment responsible for the pinkish hue of the skin

18. Sweat Glands
Different types prevent overheating of the body; secrete cerumen and milk
___________________ sweat glands – found in palms, soles of the feet, and forehead
_ ___________________ sweat glands – found in axillary and anogenital areas
___________________ glands – modified apocrine glands in external ear canal that secrete cerumen
___________________ glands – specialized sweat glands that secrete milk

19. Sebaceous Glands
Simple ___________________ glands found all over the body
Soften skin when stimulated by ___________________
Secrete an oily secretion called ___________________

20. Hair
Filamentous strands of dead ___________________ cells produced by ___________________ __________
Contains hard keratin which is ___________________ ___________________ than soft keratin of the skin
Made up of the ___________________ projecting from the skin, and the ___________________ embedded in the skin
Consists of a core called the ___________________ ___________________ ___________________
Pigmented by ___________________ at the base of the hair

21. Hair Function and Distribution
Functions of hair include:
Helping to maintain ___________________
Alerting the body to ___________________ ___________________ on the skin
Guarding the scalp against ___________________ ___________________ ___________________

22. Hair Function and Distribution
Hair is distributed over the entire skin surface except:
___________________ ___________________
___________________ and portions of the ___________________ ___________________

23. Hair Follicle
Root sheath extending from the ___________________ into the ___________________
Deep end is expanded forming a _______________
A knot of sensory nerve endings (a root hair ___________________) wraps around each hair bulb
Bending a hair stimulates these endings, hence our hairs act as ___________________ ___________________ ___________________

24. Hair Follicle
Figure 5.5a

25. Hair Follicle
Figure 5.5c

26. Types of Hair
___________________ – pale, fine body hair found in children and the adult female
___________________ – coarse, long hair of eyebrows, scalp, axillary, and pubic regions

27. Hair Thinning and Baldness
___________________– hair thinning in both sexes
True, or frank, baldness
___________________ determined and ___________________ condition
Male pattern baldness – caused by follicular response to DHT

28. Structure of a Nail
Scale-like ___________________ of the epidermis on the ___________________ , ___________________ surface of fingers and toes
Figure 5.6

29. Functions of the Integumentary System
___________________– chemical, physical, and mechanical barrier
___________________ regulation is accomplished by:
___________________ (cooling) and ___________________ (warming) of dermal vessels
Increasing sweat gland secretions to cool the body
___________________ ___________________– exoreceptors sense touch and pain

30. Functions of the Integumentary System
___________________ functions – synthesis of ___________________ in dermal blood vessels
___________________ reservoir – skin blood vessels store up to 5% of the body’s blood volume
___________________ – limited amounts of ___________________ wastes are eliminated from the body in sweat

31. Skin Cancer
Most skin tumors are ___________________ and do not ___________________
Metastasize means ______________________
A crucial risk factor for nonmelanoma skin cancers is the disabling of the ___________________
Newly developed skin lotions can fix damaged DNA

32. The three major types of skin cancer are:
___________________ ___________________

33. Basal Cell Carcinoma
Least ___________________ and most common skin cancer
Stratum basale cells ___________________ and invade the dermis and hypodermis
Slow growing and do not often metastasize
Can be cured by ___________________ ___________________ in 99% of the cases

34. Squamous Cell Carcinoma
Arises from ______________________________ of stratum spinosum
Arise most often on ___________________ ___________________ ___________________
Grows rapidly and ___________________ if not removed
Prognosis is good if treated by ___________________ therapy or ___________________ surgically

35. Melanoma
Cancer of melanocytes is the most dangerous type of skin cancer because it is:
Highly __________________________________
Resistant to ______________________________

36. Skin Cancers
Figure 5.7a–c

37. Melanomas have the following characteristics (ABCD rule)
A: Asymmetry; the two sides of the pigmented area do not match
B: Border is irregular and exhibits indentations
C: Color (pigmented area) is black, brown, tan, and sometimes red or blue
D: Diameter is larger than 6 mm (size of a pencil eraser)

38. Melanoma
Treated by wide surgical excision accompanied by immunotherapy
Chance of survival is poor if the lesion is over 4 mm thick

39. Burns
First-degree – only the ___________________ ___________________ is damaged
Symptoms include localized redness, swelling, and ___________________

40. Burns
Second-degree – ___________________ and upper regions of ___________________ are damaged
Symptoms mimic first degree burns, but ___________________ also appear

41. Third-degree – entire thickness of the skin is damaged
Burns
Third-degree – entire thickness of the skin is damaged
Burned area appears gray-white, cherry red, or black; there is no initial ___________________ or ___________________ (since nerve endings are destroyed)

42. Estimates the severity of burns Burns considered critical if:
Rule of Nines
Estimates the severity of burns
Burns considered critical if:
Over 25% of the body has second-degree burns
Over 10% of the body has third-degree burns
There are third-degree burns on face, hands, or feet

43. Rule of Nines
Figure 5.8a

44. Developmental Aspects of the Integument: Fetal
Epidermis develops from ___________________
Dermis and hypodermis develop from ___________________
___________________ – downy coat of delicate hairs covering the fetus
___________________ ___________________– substance produced by sebaceous glands that protects the skin of the fetus in the amnion

45. Developmental Aspects of the Integument: Adolescent to Adult
Skin and hair become ___________________ and acne may appear
Skin shows the effects of cumulative environmental assaults around age ___________________
Scaling and ___________________ become more common

46. Developmental Aspects of the Integument: Old Age
Epidermal replacement of cells ___________________ and skin becomes ___________________
Skin becomes _______________________________
Subcutaneous fat layer diminishes, leading to intolerance of ___________________
Decreased ___________________ and loss of subcutaneous tissue leads to ___________________
Decreased numbers of melanocytes and Langerhans’ cells increase the risk of ______________________