Histology - Epithelial Cells

What is the shape and function of Squamous epithelium cells? What are some details about the nucleus? Examples?

Cell shape: Thin shape

Function: exchange/diffusion

Flat nucleus

• Nucleus near top/edge of cell

Examples: lungs

What is the shape and function of Cuboidal epithelium cells? What are some details about the nucleus? Examples?

Cell Shape: rough equal height/width, cube-like

Function: protection or absorption

Spherical nucleus

• nucleus is in the middle

Examples: intestines, kidney

What is the shape and function of Columnar epithelium cells? What are some details about the nucleus? Examples?

Cell shape: Tall

• height bigger than width

Function: secretion or absorption

Nucleus near bottom

Examples: Stomach lining secretes juice into stomach

What does “simple” in the term “simple squamous” mean?

Simple — one layer

What does “stratified” the term “stratified squamous” mean?

Stratified — multiple layers

Do epithelial cells receive bloodflow? How do they receive nutrients?

Not directly — they are avascular

• Avascular: lacks blood vessels

• They receive nutrients by simple diffusion and absorption from the blood vessels in the underlying tissue

How many types of pseudostraified columnar epithelium are there? What is the shape and function of Pseudostratified columnar epithelium cells? What are some details about the nucleus? Examples?

2 types:

• Ciliated (usually)— has cilia

  • ex: respiratory tract — uses mucus to trap pathogens and cilia to sweep them out

• Nonciliated — does not have cilia

  • epididymid and vas deferens — absorb fluids and secretions to concentrate sperm

Shape: Looks like simple columnar; but squished irregularly

Function: protection, secretion, and transport

Nucleus: scattered all over the place

Houses goblet cells

What is the shape and function of Transitional epithelium cells?

Function: stretch and expand

Looks like: squamous and cuboidal

examples of simple squamous epithelium

• endothelium — lines blood vessels

• mesothelium — lines body cavities

  • pleura, peritoneum, pericardium

Examples of Stratified squamous epithelia variations

Keratinized

Nonkeratinized

Parakeratinized