Chapter 3: Histology - Aastha Kaneria

What is Histology?

The study of tissues

What is cell differentiation?

Developmental process that results in the formation of specialized cells

What are the four types of tissue in the body?

Connective, Muscle, Nerve, and Epithelial

What are the three general characteristics of epithelial tissues?

Stick close to one another, contains no blood vessels, and covering a body surface or lining body cavities

What does avascular mean

without vessels

What are three ways epithelial tissue are classified?

Squamous, cuboidal, and columnar

What are simple cells?

Single layer of cells

What are stratified cells?

Multiple layers of cells

How do squamous cells look?

They are flat

How do cuboidal cells look?

Boxy shape

How do columnar cells look?

Column shape

What are the three types of cellular modifications?

cilia, microvilli, and mucus-secreting (goblet)

What type of cells do you find cellular modifications on?

Columnar Epithelial cells

What are cilia?

fine motile hairs

What are microvilli?

Finger-like extensions of the cell

What are goblet cells?

Secretes mucus

Where do you find simple squamous epithelial cells?

alveoli (air sacs) of the lungs, lining of all blood vessels, and various membranes in the body

Where do you find simple cuboidal cells?

urinary tubules of kidney, liver, pancreas, thyroid, and other glands

What does Aden/o mean?

Gland

Where do you find simple columnar ciliated epithelial tissues?

Lining of Fallopian tubes

What do cilia on the fallopian tube do?

transport the egg from the ovary 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 respiratory tract

What does pseudo mean?

False

What does pseudostratified mean?

False stratified

What does cilia on the respiratory tract do?

Catch dust

Where do you find transitional epithelium?

Lining of urinary blatter

Why is it called transitional epithelium?

The tissue becomes stretches as the bladder fills up

What does lumen mean?

Hole in the blood vessel

What are the two subtypes of stratified squamous epithelium?

Non-Keratinizing/Keratinizing Stratified Squamous Epithelium

What is keratin

Hardening protein

Where do you find keratin?

Hair, Nails, Skin

What are non-keratinizing stratified squamous epithelium?

No dead layers of cells.

Where do you find non-keratinizing stratified squamous epithelium?

Lining of oral cavity, anal canal, and vaginal canal.

What is keratinizing stratified squamous epithelium?

Dead layers of cells

Where do you find keratinizing stratified squamous epithelium?

Epidermis of skin

What do all cells need to be surrounded by?

Fluid

What is the function of connective tissue?

To connect and support other tissues in the body

How are connective tissues classified?

Type of cells and intercellular matter

What is areolar loose connective tissue?

Cells present in it are fibroblasts, macrophages, and mast cells

What are fibroblasts?

main type of cell. Secretes proteins into spaces between cells. Collagen and Elastin

What are macrophages?

Engulf foreign cells

What are mast cells?

Inflammation. Secrete histamine and other chemical mediators of inflammation

What is inflammation?

When your injury swells up, starts to hurt, and turns red

What does erythema mean?

dilation of blood vessels

What is edema?

Swelling

What two proteins are secreted by fibroblasts?

Collagen and Elastin

What is collagen?

Strengthening protein. Confer strength to tissue

What is elastin?

Confer elasticity to the tissue

What is adipose tissue?

Fat. Closely packed cells each containing a fat-filled vacuole

What is the function of adipose tissue?

Reserve of food, insulates, and supports and protects the organs

What are three common locations of adipose tissue

Skin (subcutaneous fat), kidneys and eyeballs, buttocks and breasts

What are the two subtypes of dense fibrous connective

Regularly arranged Dense Fibrous C.T. and Irregularly arranged Dense Fibrous C.T.

What are 5 places where dense fibrous connective tissue is common?

Tendons (muscle to bone), Ligaments (bones to bones), Dura mater (brain and spinal cord), Fascia (encloses muscle), and Perichondrium/Periosteum (encloses cartilage and bone)

What does peri mean?

Around

How do regularly arranged dense fibrous connective tissue look?

parallel bundles

How do irregularly arranged dense fibrous connective tissue look?

interwoven, all directions

What is special about cartilage tissue, unlike other connective tissues

Contains no blood vessels

What are the three subtypes of cartilage?

Hyaline, Fibrocartilage, and Elastic Cartillage

Where is hyaline cartilage found?

long bones of body, front of the nose, trachea and larynx, articulating bones

Where is fibrocartilage found?

intervertebral disks.

Where is Elastic cartilage found?

External ear (pinna)

What are osteocytes?

Bone cells. Surrounded by a pocket of fluid called a lacuna

What does a compact bone look like?

Around the outside of the bone. Hard

What does spongy bone look like?

On the inside of the bone

What are osteoblasts?

Cells that secrete calcium minerals (form bone tissue)

What are osteoclasts?

They break down calcium minerals (bone resorption)

What is resorption?

Tissue or bone is broken down

What is ossification?

Forming bone tissue

What are haversian systems?

structure of compact bone

What is diaphysis?

Shaft of the bone

What is epiphysis?

End part of the long bone. Bottom of shaft

What is in the medullary cavity?

Red marrow

What is hemopoiesis?

Production of blood cells and platelets

What is a hemopoietic tissue?

Made up of RBC, WBC, and platelets. Production of blood

What are erythrocytes

Red blood cells (Transport O2 and Co2)

What are Leukocytes?

White Blood Cells. Produce antibodies and interferon that inactivate foreign agents

What are platelets?

Produce thromboplastin

What is thromboplastin?

Triggers blood clotting

What are neoplasms

Tumors

What are benign tumors?

Increased multiplication of tissue cells (mitosis)

What are malignant tumors?

Tumors (cancer). Abnormal cell growth.