Aashka Chokshi : CHAPTER 3 - Histology

What is Histology?

The study of tissues

What is cell differentiation?

Cell differentiation is the process by which a less specialized cell becomes a more specialized cell type

What are the four types of tissue in the body?

Epithelial, Connective, Muscle, and Nervous

What are the three general characteristics of epithelial tissue?

Adhere closely to each other, are avascular, and cover a body surface or line the cavities of the body

What does avascular mean?

Contains no blood vessels

What are the three ways epithelial tissue is classified?

Number of cell layers, cell shape, and presence of surface modifications

What are simple cells?

Cells arranged in a single layer

What are stratified cells?

Cells arranged in multiple layers

How do squamous cells look?

Flat

How do cuboidal cells look?

Boxy (cube-shaped)

How do columnar cells look?

Tall & Skinny

What are the three types of cellular modifications?

Cilia, microvilli, and goblet cells

What type of cells do you find cellular modifications on?

On Epithelial cells

What are cilia?

Fine motile hairs

What are microvilli?

Small, finger-like extensions which increase surface area

What are goblet cells?

Cells which secrete mucus

Where do you find simple squamous epithelial cells?

Lining blood vessels and membranes

Where do you find simple cuboidal cells?

Urinary tubules of the kidney, liver, pancreas, thyroid and other glands

What does Aden/o mean?

Gland

Where do you find simple columnar ciliated epithelial cells?

Lining of women’s fallopian tubes

What do cilia on the fallopian tube do?

Carry eggs from ovaries to the uterus

Where do you find simple columnar epithelium with goblet cells?

Lining of the stomach

What do goblet cells in the stomach do?

Neutralize stomach acid

Where do you find simple columnar brush-border epithelium with goblet cells?

Lining of the intestine

Where do you find pseudostratified columnar ciliated epithelium with goblet cells?

Lining of the respiratory tract

What does "pseudo" mean?

False

What does pseudostratified mean?

The nuclei appear to be at different levels because the columnar cells are not all the same height

What does cilia on the respiratory tract do?

Catch dust

Where do you find transitional epithelium?

Lining of the urinary bladder

Why is it called transitional epithelium?

Changes shape as it’s filled with fluid

What does lumen mean?

A hole

What are the two subtypes of stratified squamous epithelium?

Keratinized and Non-Keratinized

What is keratin?

A hardening protein

Where do you find keratin?

Skin, Hair and Nails

What are non-keratinizing stratified squamous epithelium?

Have no dead layer of cells

Where do you find non-keratinizing stratified squamous

Oral Cavity, Anal Canal, and Vaginal Canal

What is keratinizing stratified squamous epithelium?

Has a dead layer of cells

Where do you find keratinizing stratified squamous epithelium?

Skin

What do all cells need to be surrounded by?

Fluid

What is the function of connective tissue?

Connect and support other tissues of the body

How are connective tissue classified?

On the intercellular matter found between the cells

What is areolar loose connective tissue?

Collagen and Elastin

What are fibroblasts?

Secrete proteins into the space between the cells

What are macrophages?

Engulf foreign agents

What are mast cells?

Secrete histamine

What is inflammation?

Swelling, Reddening, and Pain

What does erythema mean?

Red

What is edema?

Swelling

What two proteins are secreted by fibroblasts?

Collagen Protein and Elastin Protein

What is collagen?

Confer strength to the tissue

What is elastin?

Confer elasticity to the tissue

What is adipose tissue?

Fat Connective Tissue

What is the function of adipose tissue?

Provides a reserve of food, insulates against heat loss, supports and protects the organs it encloses

What are three common locations of Adipose Tissue?

Under the skin, around the kidneys & eyeballs, buttocks & breasts

What are the two subtypes of dense fibrous tissue?

Regularly Arranged and Irregularly Arranged

What are five places where dense fibrous connective tissue is found?

Tendons, Ligaments, Dura Mater, Fascia, Perichrondous & Periosteum

What does peri mean?

Around

How do regularly arranged dense fibrous tissues look?

Protein fibers arranged in parallel bundles

How do irregularly arranged dense fibrous tissues look?

Protein fibers interwoven

What is special about cartilage tissue?

It’s a vascular (doesn't have blood cells)

What are the three subtypes of cartilage?

Hyaline Cartilage, Fibrocartilage, Elastic Cartilage

What are four locations where Hyaline Cartilage is found?

The embryonic long bones of the body, the front of the nose, the trachea & larynx, the surfaces of articulating bones

Where is Fibrocartilage found?

Intervertebral disks

Where is Elastic Cartilage found?

The external ear (pinna)