HISTOLOGY NOTES


NOTES

CHECKING for UNDERSTANDING REVIEW QUESTIONS

I. Epithelial tissues

A. General Characteristics

1. covers all free body surfaces and lines organs

2. anchored to connective tissue by basement membrane

3. lacks blood vessels

4. can reproduce

B. Functions--in protection, secretion, absorption, excretion, and sensory reception

C. Classification

1. simple--consists of one layer of cells

2. stratified--two or more layers of cells

3. pseudostratified--appears to be layered but it is not

D. Cell Composition

1. squamous cells--flat or irregularly shaped cells

2. cuboidal--look like small cubes

3. columnar--taller than they are wide; rectangles

4. transitional--changes shape from squamous to cuboidal

E. Types

1. simple squamous--single layer of flattened cells; functions in exchanges of gases in the lungs and lines the blood vessels

2. simple cuboidal--single layer of cube-shaped cells; caries on secretion and absorption in the kidneys, salivary gland, ovaries and the thyroid.

3. simple columnar--single layer of rectangular cells whose nuclei are located near the basement membrane; lines the uterus and digestive tract; contains goblet cells that secrete mucus

4. pseudostratified columnar--appears layered but is not because the nuclei are located in two or more levels; contains both goblet cells and cilia; lines the respiratory and reproductive systems

5. stratified squamous--composed of many layers of flat cells; covers the skin and lines the mouth,throat, vagina, and anal canal

6. transitional--a specialized form of stratified tissue that appears to change shape depending on whether the bladder is empty or full

F. Classification According to Location/Function

a. Glandular epithelium--composed of epithelial cells that produce a specific secretion or excretion of waste products

1. exocrine glands--secrete their products into one or more ducts that open into the skin or mucous membranes

2. endocrine glands--do not have ducts but secrete their products into the blood (hormones)

 

Why is it important that epithelial not have blood?

 

What does the lack of blood prevent it from doing?

 

 

Name several functions of epithelial tissue.

 

How will you be able to tell the difference between simple, stratified and pseudostratified?

 

Draw a small picture of each of the cell shapes.

 

 

 

 

Restate each type of epithelial tissue and then describe it.

 

After you complete this, go to the main histology page and look at each slide of these tissues under LAB 1. Can you tell them apart?

 

 

 

 

 

 

 

 

 

 

 

 

 

II. Connective Tissue

A. General Characteristics

1. connects, supports, protects, provides framework, fills spaces, stores fat, and produces blood cells

2. consists of cells, usually some distance apart, and intercellular material

3. able to reproduce

4. usually has a good blood supply

B. Cell Types

1. fibroblasts--form the various fibers

2. macrophages--active phagocytes that move through connective tissue engulfing foreign matter and dead or dying cells

C. Intercellular Material

1. formed of ground substances and fibers

2. 3 types of fibers

a. collagenous fibers--most abundant type; appears in bands; also known as white fibers

b. elastic fibers--composed of elastin; pliable and elastic; also known as yellow fibers

c. reticular fibers--highly branched; short, thin and delicate

D. Tissue Types

1. loose connective tissue--most widely distributed; found beneath the skin and between muscles

2. adipose tissue--a specialized form of loose that stores fat; found beneath the skin and around the kidneys, heart, and various joints

3. fibrous connective tissue--composed of strong, collagenous fibers; found in tendons and ligaments

4. elastic connective tissue--composed of elastic fibers with fibroblasts; found in the walls of the arteries, bronchial tubes and vocal cords

5. cartilage

a. provides support and framework for various parts

b. chondrocytes--cartilage cells

c. lacunae--small chambers which house the chondrocytes

d. lacks a direct blood supplies

e. types of cartilage

(1). hyaline--most common type; occurs on the ends of bones, nose and rings in the walls of the respiratory tract

(2). elastic--more flexible; found in the ear and part of the larynx

(3). fibrocartilage--very tough tissue; found between the bony parts of the backbone and the knee

6. bone

a, most rigid of the connective tissues

b. function--supports the body; protects vital parts; serves as a point of attachment for muscles; forms blood cells and stores various minerals

c. osteocytes--bone cells

d. red and yellow marrow--occupies the space within the bone

e. periosteum--outer covering of the bone

7. blood--composed of cells (red, white and platelets) suspended in a fluid (plasma); formed in the bone marrow

8. reticular connective tissue--composed of many phagocytic cells; protects body against invasion; found in lymph

 

How is connective tissue different from epithelial tissue?

 

 

 

 

What cells comprise connective tissue and what do they do?

 

 

How closely packed are the cells of:

  • epithelial?
  • connective?

What fibers compose connective tissue and how are they different?

 

 

 

 

Restate each type of epithelial tissue and then describe it.

 

 

After you complete this, go to the main histology page and look at each slide of these tissues under LAB 2. Can you tell them apart?

III. Muscle Tissue

A. General Characteristics--moves parts attached to it; cell called a fiber; fibers change shape in order to move

B. Types

1. skeletal muscles--attached to bones; have striations; voluntary; multinucleic

2. smooth muscle--found in the wall of internal organs; no striations; involuntary; mononucleic

3. cardiac muscle--found in the heart; striated; involuntary; have a single nuclei; have intercalated discs that connect between cells

How is muscular tissue different from epithelial and connective tissue?

Name the three types of muscle tissue. Give the differences in:

  • location
  • striations
  • voluntary/involuntary

After you complete this, go to the main histology page and look at each slide of these tissues under LAB 3. Can you tell them apart?

IV. Nervous Tissue

A. function--transmit nerve impulses; coordinates and regulates body activities

B. location--brain, spinal cord, and nerves

C. neurons--nerve cells

D. neuroglial cells--bind and support nerve tissue; carry on phagocytosis; connect neurons to blood vessels

 

How is nervous tissue different from epithelial, connective and muscle tissue?

 

After you complete this, go to the main histology page and look at each slide of these tissues under LAB 3. Can you tell them apart?

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