Chapter 4

Question 1

1. What is a definition for tissue? What is the study of tissues called?

Answer 1

Tissues - Collection of specialized cells and cell products that carry out a limited number of functions

Histology

Question 2

2. Name the 4 categories of tissues in the human body and briefly describe each type of tissue.

Answer 2

1. Epithelial tissue - Covers exposed surfaces, lines internal passageways and chambers, and forms glands
2. Connective tissue - Fills internal spaces, provides structural support for other tissues, transports materials within the body, and stores energy
3. Muscle tissue - Specialized for contraction and includes the skeletal muscles of the body, the muscles of the heart, and the muscular walls of hollow organs
4. Nervous tissue - Carries information from one part of the body to another in the form of electrical impulses.

Question 3

3. Distinguish between epithelia and glands.

Answer 3

Epithelia - layers of cells that cover external or line internal surfaces

Glands - Are structures that produce fluid secretions

Question 4

4. List five important characteristics of epithelial tissue.

Answer 4

1. Polarity
2. Cellularity
3. Attachment
4. Avascularity
5. Regeneration

Question 5

5. Identify and describe the four essential functions of epithelial tissue.

Answer 5

1. Provide physical protection - Protect exposed and internal surfaces from abrasion, dehydration, and destruction by chemical or biological agents
2. Control permeability - Any substance that enters or leaves the body must cross an epithelium
3. Provide sensation - Most epithelial are extremely sensitive to stimulation, because they have large sensory nerve supply
4. Produce Specialized Secretion - Epithelial cells that produce secretions are called gland cells. Individual gland cells are usually scattered among other types in an epithelium.

Question 6

6. What is the probable function of an epithelial surface whose cells bear many microvilli? Where in the body can these specialized cells be found?

Answer 6

Increase surface volume

Where absorption and secretion take place

Question 7

7. What is the probable function of an epithelial surface whose cells bear cilia? Where in the body can these specialized cells be found?

Answer 7

Movement of substances over the epithelial surface

Respiratory tract

Question 8

8. Identify and describe the three most common types of epithelial cell junctions. Provide an example of a location in the human body where each of these junctions is utilized.

Answer 8

Gap junction - Two cells held together by two embbeded interlocking transmembrane proteins connection.
- Epithelial cells, cilia

Tight junctions - The lipid portions of the two plasma membranes are tightly bound together by interlocking membrane proteins
- Apical regions of epithelial cells

Desmosomes- CAMs and proteoglycans link the opposing plasma membranes
- Epithelium

Question 9

9. Epithelial cells often have a hard life!! What type of cell is necessary to maintain the structure of epithelia?

Answer 9

Stem Cells

Question 10

10. Epithelia can easily be sorted into categories based on what two criteria?

Answer 10

Epithelia and glands

Question 11

11. What three basic shapes do epithelia possess?

Answer 11

Squamous

Cuboidal

Columnar

Question 12

12. Once you have determined the shape of the superficial cells, then you will need to look at the number of cell layers. You have two options, what are they?

Answer 12

Simple

Stratified

Question 13

13. Name the functions and locations of simple squamous epithelium.

Answer 13

Protected regions where absorption or diffusion takes place

Alveoli
Lining of the thoracic and abdominopelvic body cavities
Lining of the heart and blood vessels

Question 14

14. Name the functions and locations of stratified squamous epithelium.

Answer 14

Located where mechanical stresses are severe.

Surface of the skin
Lining of the mouth, esophagus, and anus

Question 15

15. What is keratin? What function does it perform? Provide examples of keratinized and nonkeratinized stratified squamous epithelia.

Answer 15

1. Protein
2. Tough and water resistant - are keratinized
3. Nonkeratinized resists abrasion, but will dry out and deteriorate unless kept moist

Question 16

16. Name the functions and locations of simple cuboidal epithelium.

Answer 16

1. Limited protection, secretion, and absorption

2. Glands, ducts, kidneys, thyriod

Question 17

17. Name the functions and locations of stratified cuboidal epithelium.

Answer 17

1. Protection, absorption, and secretion

2. Lining of some ducts

Question 18

18. Name the function and locations of transitional epithelium.

Answer 18

Permits repeated stretching without damage

Urinary bladder, renal pelvis, ureters

Question 19

19. Name the functions and locations of simple columnar epithelium.

Answer 19

Protection, secretion, and absorption

Lining of the stomach, intestine, gall bladder, uterine tubes, and collecting ducts of kidneys

Question 20

20. Name the functions and locations of pseudostratified columnar epithelium. What structures typically line the apical surface of pseudostratified columnar epithelia?

Answer 20

Protection, secretion, move mucus with cilia

Nasal cavity, trachea, and bronchi, portions of the male reproductive tract

Question 21

21. Compare and contrast endocrine and exocrine glands.

Answer 21

Endocrine - Release secretions into the blood

Exocrine - Release secretions into an epithelia surface or a duct

Question 22

22. What are the secretions from endocrine glands called?

Answer 22

Hormones

Question 23

23. Name several locations where endocrine glands are located in the body.

Answer 23

Thyroid
Thymus
Pituitary glands

Question 24

Exocrine glands have several different modes of secretion. Distinguish between the modes of secretion and provide examples of each…

Merocrine secretion

Answer 24

Secretory vesicles through exocytosis mucous secretions of the salivary glands.

Question 25

Exocrine glands have several different modes of secretion. Distinguish between the modes of secretion and provide examples of each... Apocrine secretion

Answer 25

Loss of cytoplasm as well as the secretory product

Question 26

Exocrine glands have several different modes of secretion. Distinguish between the modes of secretion and provide examples of each... Holocrine secretion

Answer 26

Destroys the gland cell. Sebaceous glands with hair follicles

Question 27

26. What are the three basic components of connective tissue? What is matrix?

Answer 27

1. Specialized cells 2. Extracellular protein fibers 3. Fluid - ground substance matrix (surrounds the cell) - extracellular fibers and ground substance

Question 28

Fibroblast

Answer 28

Production of the connective tissue fibers

Question 29

Fibrocyte

Answer 29

Maintenance of the connective tissue fibers

Question 30

Adipocyte

Answer 30

Energy storage

Question 31

Mesenchymal cells

Answer 31

Stem cells which can differentiate into fibroblasts

Question 32

Mast cells

Answer 32

Release histamine and heparin

Question 33

Macrophages

Answer 33

Phagocytes that engulf damaged cells or pathogens

Question 34

Lymphocytes

Answer 34

Defense of the body; some produce antibodies

Question 35

Melanocytes

Answer 35

Produce a brown pigment called melanin

Question 36

28. Many allergy sufferers take antihistamines to relieve their allergy symptoms. Which cells produce the molecule that this medication blocks?

Answer 36

Mast cells

Question 37

29. List the three types of connective tissue fibers and their primary function.

Answer 37

1. Collagen - tendons and ligaments 2. Reticular - resists force from many directions 3. Elastic - after streaching, return to original length

Question 38

30. List the 3 types of loose connective tissue in adults, where they are normally found in the body, and their primary function.

Answer 38

Areolar - Dermis of the skin, digestive, respiratory, urinary, between muscles, around joints, blood vessels, and nerves. - Cushions, provides support, phagocytics cells for defense Adipose - Under the skin of the sides, buttocks, and breast. Behind the eyes and around the kidneys - Provide padding, absorbs shock, insulator, and filler Reticular - Liver, kidneys, and spleen - Supports the functional cells of the organ, forms a 3D stroma

Question 39

31. Distinguish between dense regular and dense irregular connective tissue. Provide examples of each type of connective tissue in the human body.

Answer 39

Regular - collagen fibers are parallel to each other, tightly packed (tendons) Irregular - collagen is interwoven in no consistent (dermis)

Question 40

32. _____________________ connect muscle to bone. __________________ connect bone to bone.

Answer 40

Tendons Ligaments

Question 41

33. What cell stimulates the inflammatory process by releasing histamine, heparin, and prostaglandins?

Answer 41

Mast cells

Question 42

34. List the four signs of inflammation

Answer 42

Redness, swelling, heat, and pain

Question 43

35. Define necrosis.

Answer 43

Tissue destruction after cells have been damaged or killed

Question 44

36. What is pus? What is an abscess?

Answer 44

Pus - Collection of debris, fluid, dead / dying cells Abscess - Accumulation of pus in an enclosed tissue space

Question 45

37. Briefly describe which tissues regenerate well and those which regenerate poorly.

Answer 45

Well - Epithelia, connective tissues, smooth muscle, skin Poorly - Skeletal and cardiac muscles and nervous tissues

Question 46

38. Identify some age-related factors that affect tissue repair and structure.

Answer 46

Maintenance activities decrease Rate of energy decreases Hormonal alterations

Question 47

39. What would account for the observed increase in cancer rates with age?

Answer 47

Longer exposure to chemical and environmental factors