Lab 1: Microscopy, Histology and Integumentary System

1 (compound light microscope)

ocular lens

2

body tube

3

nosepiece

4

arm

5

objective lenses

6

stage

7

coarse-focus knob

8

fine focus knob

9

condenser

10

mechanical stage control knob

11

iris diaphragm lever

12

light source

13

base

14

on/off switch

A

coverslip

B

specimen in drop of water

C

microscope slide

Problem with microscope: nothing is visible in the lense

Solutions:

• plug in microscope

• turn the power supply on

• rotate the objective lens until you hear it click into place

• the bulb is burned; replace the bulb

Problem with microscope: you see a dark crescent

solution: The objective lens is not in the proper position; click the lens into place

Problem with microscope: All you see is a light circle

solution:

• The microscope is out of focus; adjust the coarse-focus knob

• The light is up too high; turn down the light

• the iris diaphragm is open too much; close it down

A

diagram of simple squamous epithelium

1

free surface

2

nucleus

3

basement membrane

4

simple squamous epithelial cell

B

photomicrograph of mesothelium, surface view 400x

5

cell nucleus

6

cell membrane

C

photomicrograph of lung tissue, side view 1000x

7

cell membrane

8

nucleus

A

diagram of simple cuboidal epithelium

1

Free surface

2

nucleus

3

simple cuboidial epithelial cell

4

basement membrane

B

photomicrograph of kidney, long section (400x)

5

cell membrane

6

nucleus

7

basement membrane

C

photomicrograph of kidney, cross section (400x)

8

nucleus

9

cell membrane

10

basement membrane

A

diagram of simple columnar epithelium

1

free surface

2

goblet cell containing mucus

3

nucleus

4

simple columnar epithelial cell

5

basement membrane

B

photomicrograph of stomach (400x)

6

cell membrane

7

nucleus

8

basement membrane

A

diagram of pseudostratified ciliated columnar epithelium

1

cilia on free surface

2

free surface

3

goblet cell containing mucus

4

plasma membrane

5

nucleus

6

basement membrane

B

photomicrograph of trachea (400x)

A

diagram of stratified squamous epithelium

1

free surface

2

nonkeratinized stratified squamous epithelial cell

3

nuclei

4

basement membrane

B

photomicrograph of esophagus (400x)

5

plasma membrane

6

nucleus

7

basement membrane

A

diagram of unstretched transitional epithelium tissue

1

free surface

2

transitional epithelial cell

3

nucleus

4

basement membrane

B

diagram of stretched transitional epithelial tissue

5

free surface

6

transitional epithelial cell

7

nucleus

8

basement membrane

C

pictograph of bladder (400x)

9

apical surface

10

cell membrane

11

nucleus

12

basement membrane

Epithelial Classification

Layer: SIMPLE

Cell Shapes (4):

Simple squamous epithelium

Simple cuboidal epithelium

Simple columnar epithelium

Pseudostratified columnar epithelium

Epithelial Classification

Layer: STRATIFIED

Cell Shapes (2):

Stratified squamous epithelium

Transitional epithelium

epithelial tissues

The tissues that cover body surfaces, line cavities, and form glands, characterized by closely packed cells and minimal extracellular matrix. They are classified based on the number of layers and cell shapes.

Basement membrane

A thin, noncellular adhesive layer that separates epithelial tissues from underlying connective tissues, providing support and anchoring the epithelium.

Cell Shape: Squamous

flattened

Cell shape: cuboidal

cube-like

Cell shape: columnar

tall and column-like

Cell shape: pseudostratified

a single layer of cells with varying heights, appearing stratified

Simple

cells in a single layer

Stratified

cells stacked in more than 1 layer

epithelial tissue is most commonly found on these surfaces

Free surfaces

simple squamous epithelium characteristics

• It consists of a single layer of flat cells

• smooth/slippery surface surface: diffusion and filtration

• lines air sacs of lungs

• lines blood vessels (endothelium)

• surface layer of many membranes in various body cavities (mesothelium)

simple cuboidal epithelium characteristics

• It consists of a single layer of cube-shaped cells

• functions in secretion and reabsorption

• lines kidney tubules

• form many major glands and glandular organs (major tissue of the kidneys)

simple columnar epithelium characteristics

• It consists of a single layer of column-shaped cells

• nuclei are frequently in a row

• can be ciliated on apical surface or have microvilli

• cells with microvilli line inner portion of d. tract (absorption)

• mucus-secreting goblet cells are often present

• ciliated cells: line the uterine tubes