Ch. 4 Tissues (Study Guide)

Question 1

Define a “Tissue”

Answer 1

A collection of specialized cells and cell products that perform a specific function.

Question 2

Name the four types of tissues in the body

Answer 2

• Epithelial
• Connective
• Muscular
• Neural

Question 3

Describe the general characteristics of epithelial tissues

Answer 3

• Unique (Apical surface) exposed to the environment
• Closely packed & attached to each other
• A layer of cells that forms a superficial covering or an internal lining of a body cavity or vessel.

Question 4

List the 2 main subtypes of epithelial tissue

Answer 4

• Glandular (Endocrine & Exocrine glands)
• Surface epithelium

Question 5

What is an endocrine gland? Give examples of specific endocrine glands.

Answer 5

A gland that secretes hormones into the blood and interstitial fluid

EX: Thyroid, pituitary

Question 6

What is an exocrine gland? Give examples of specific exocrine glands.

Answer 6

A gland that secretes onto the body or into a passageway connected to the exterior

EX: Oil, sweat

Question 7

Describe the basic structure of an epithelial membrane, and list the 3 main types
found in the body.

Answer 7

Basic structure: combination of epithelial tissue attached to connective tissue. Connection occurs at the basement membrane.

3 types: Mucous, Serous, Cutaneous

Question 8

Describe the structure, functions and locations of the specific epithelial membranes
found in the body.

Answer 8

1. Mucous

• Structure: Lines body cavities that open to exterior environment.
• Function: Epithelial cells secrete mucous to moisten & protect surface.
• Location: Linings of digestive tract.

2. Serous

• Structure: Two layers. Parietal (lines cavity wall) and Visceral (covers organs within cavity)
• Function: Epithelial cells secrete serous fluid, a watery fluid that lubricates surface of membranes to decrease friction.
• Location: Lines internal ventral body cavities and covers organs with the cavity. Pleura, Pericardium.

3. Cutaneous (Skin)

• Structure: Dermis (connective layer) & epidermis (epithelial layer)
• Function: Covers and protects body surface from external environment.
• Location: Surface of body

Question 9

Covering & lining epithelium is classified on the basis of:

Answer 9

Number of layers & cell shape

Question 10

Define/describe the following:
a. Simple epithelium
b. Stratified epithelium
c. Pseudostratified epithelium
d. Squamous cells
e. Cuboidal cells
f. Columnar cells
g. microvilli
h. cilia
i. goblet cells

Answer 10

1. Number of layers:
   - simple: 1 layer of cells
   - stratified: more than 1 layer of cells
   - pseudostratified: looks like more than 1 layer but all cells contact basement membrane
2. Cell shape:
   - Squamous: flat
   - Cuboidal: cube shaped
   - Columnar: tall columns

Microvilli and cilia can sit on top of cuboidal and columnar cells

Question 11

Describe the structure, functions and locations of the following epithelial tissues:

a. simple squamous epithelial tissue
b. simple columnar epithelial tissue
c. stratified squamous epithelial tissue (keratinized and non-keratinized)
d. pseudostratified ciliated columnar epithelial tissue

Answer 11

a. simple squamous epithelial tissue
- Structure: single layer of cells, flat.
- Function: Reduces friction; controls vessel permeability; performs absorption and secretion.
- Location: Epithelia lining ventral body cavities; lining heart and blood vessels.

b. simple columnar epithelial tissue
- Structure: single layer of cells, tall columns
- Function: Secretion, absorption, some protection.
- Location: Lining of stomach, intestine, gallbladder, uterine tubes.

c. stratified squamous epithelial tissue (keratinized and non-keratinized)
- Structure: more than 1 layer of cells, flat
- Function: Provides physical protection against abrasion, pathogens and chemical attack.
- Location:
Keratinized: surface of skin
Non-keratinized: lining of mouth, throat, esophagus, rectum, anus and vagina.

d. pseudostratified ciliated columnar epithelial tissue
- Structure: only 1 layer but looks like more than 1, tall columns with cilia on top
- Function: protection, secretion, move mucus with cilia.
- Location: lining of nasal cavity, trachea and bronchi; portions of male reproductive tract.

Question 12

Describe the general characteristics of connective tissues (CT)

Answer 12

• Cells differ depending on specific type of CT; (mesenchymal, fibroblasts, chondrocytes, osteocytes)
• Cells usually widely spaced with intercellular matrix between
• Usually well vascularized (exception: cartilage)
• Usually do not regenerate easily
• Repair ability varies depending on type of CT

Question 13

What is the “matrix” of a connective tissue comprised of and why is it important to the tissue?

Answer 13

• Ground substance: varies in consistency from liquid, to gel-like, to solid, depending on specific CT.
• Protein fibers:
  • Collagen: provides strength to tissue
  • Elastic: provides elasticity
  • Reticular: provides support to tissue

The Matrix of the tissue most directly determines the functional qualities of the tissue.

Question 14

How does the ground substance of a tissue affect its function?

Answer 14

Ground substance varies in consistency from liquid, to gel-like, to solid, depending on specific CT in order to aid the specific function of the specific tissue.

Question 15

Name the fibers that may be found in connective tissues and describe their functions.

Answer 15

Protein fibers:
- Collagen: provides strength to tissue
- Elastic: provides elasticity
- Reticular: provides support to tissue

Question 16

Types of CT: (fill in the details/descriptions of these tissues)
- Mesenchyme
Name of cells in this tissue?
Why is this tissue “special”?

• Connective tissue proper:
  Most common cells?
  Consistency of ground substance?
  How can the fibers be arranged within the tissues?
• Loose connective tissue proper (what characterizes these tissues?)
  Areolar
  Describe this tissue (cells/ground substance/fibers)
  Functions?
  Locations?
  Adipose
  Describe this tissue (cells/ground substance/fibers)
  Functions?
  Locations?
• Dense connective tissue proper (what characterizes these tissues?)
  Dense regular (collagenous)
  Describe this tissue (cells/ground substance/fibers)
  Functions?
  Locations?
  Dense irregular
  Describe this tissue (cells/ground substance/fibers)
  Functions?
  Locations?
• Supportive CT:
  Cartilage
  Cells?
  Ground substance consistency?
  What is a lacuna and what is its purpose?
  What is the perichondrium and what is its purpose?
  What is unique about cartilage versus the other connective tissues?
  For each type of cartilage provide a visual description of the tissue, its
  function and specific locations
  Hyaline cartilage
  Fibrocartilage
  Elastic cartilage
• Osseous (bone) tissue
  Cells?
  Ground substance/matrix?
  Periosteum:
  For each type of bone tissue, name the functional unit
  Spongy (cancellous) bone
  Dense (compact/cortical) bone
• Fluid (liquid) CT:
  Blood
  Cells:
  Name of matrix:
  Where is this tissue found?
  Lymph
  Where is this tissue found?

Answer 16

• Mesenchyme
• Mesenchymal cells
• Only found in the developing embryo
• Connective tissue proper
• Fibroblasts are most common cells present
• Slippery, syrupy ground substance
• Arranged loosely or densely packed together
• Loose connective tissue proper
• Areolar, Adipose
• Areolar
• Function: Cushions organs, provides support but permits independent movement
  -Location: Beneath dermis of skin
• Mast cells and fat cells, collagen and elastic fibers, fibroblasts and macrophages
• Adipose
• Function: Provides padding and cushions shocks.
• Location: Deep to the skin
• Adipocytes

-Dense connective tissue proper
- Function: Provides firm attachment, conducts pull of muscles.
- Location: Between skeletal muscles and skeleton (tendons)
- Collagen fibers, Fibroblast nuclei

Dense irregular tissue
- Function: Provides strength to resist forces applied from many directions
- Location: Capsules of visceral organs
- Collagen fiber bundles

• Supportive CT
• Cartilage:
  
  • Firm gel like ground substance
  • Chondrocytes and lacunae in interstitial fluid
• Lacunae: small pockets occupied by chondrocytes. Acts as potential stimulus for the bone regeneration process.
• Perichondrium: Layer that surrounds cartilage, outer fibrous and inner cellular region. Prevents excessive dilatation of the heart.
• ## Cartilage is avascular

Question 17

Tissue injury and repair:
Describe the process of inflammation and repair
Which tissues heal well & which do not?