Introduction to Tissues and Epithelial Tissue Types

Flashcards covering tissue classifications, structural features, and specific types of epithelial tissue from Chapter 1 through Chapter 6 of the lecture.

What are the four general categories of tissue found in the human body?

Epithelial tissue, connective tissue, muscle tissue, and nervous tissue.

How do epithelial cells attach to one another to form structural layers?

They form connections using cell adhesion molecules, creating tight junctions that stop cells from being easily pulled apart.

What are the primary functions of connective tissue in the body?

It keeps everything in place, protects structures from damage, pulling, and stresses, stores long-term energy as adipose tissue, and carries immune system cells via blood.

Why does muscle contraction generate heat in the body?

Every time muscles contract to allow movement, there is significant energy expenditure, which releases heat.

What specialized cells make up nervous tissue, and what do they transmit?

Neurons, which send electrical signals called nerve impulses.

What is the apical surface of an epithelial tissue?

The unattached, free surface of epithelial tissue that faces the outside of the body or the internal space/cavity of an organ.

What is the basal surface and basement membrane in epithelial tissues?

The basal surface is the bottom attachment point where epithelial cells anchor to underlying connective tissue via the basement membrane.

How do epithelial tissues survive despite lacking a direct blood supply?

Oxygen and nutrients diffuse into the cells from high to low concentration from underlying tissue, while metabolic wastes diffuse out in the opposite direction.

How are epithelial tissues categorized by cell layer arrangements?

Simple (a single layer of cells), pseudostratified (a single layer that falsely appears multilayered), and stratified (multiple layers of cells).

Why does pseudostratified epithelium appear to have multiple layers when it only has one?

Every cell attaches to the basement membrane, but not all cells are tall enough to reach the apical surface, giving a fake multilayered appearance.

What are the three common shapes used to classify epithelial cells?

Squamous (flat like paper), cuboidal (cube-like), and columnar (column-like or rectangular).

What is the primary cellular function of simple squamous epithelium?

Cell diffusion, allowing easy transport of molecules across thin, flat cells, and providing lubricating serosal fluid in cavities.

Where is simple squamous epithelium located in the body?

In the alveoli of the lungs, glomeruli of the kidneys, endothelium lining blood vessels, and serosa (pleura and pericardium).

What are the main functions and locations of simple cuboidal epithelium?

Functions in absorption and secretion (including mucus); found in the liver, thyroid gland, mammary glands, salivary glands, bronchioles of lungs, and kidney tubules.

Where in the body can simple columnar epithelium be found?

In the digestive system, uterus, kidneys, and uterine tubes.

What specialized mucus-producing cell is found alongside pseudostratified columnar epithelium?

Goblet cells.

Where is pseudostratified epithelium found, and what is its role?

Found in the respiratory tract, digestive tract, and parts of male anatomy; uses mucus and cilia to move germs, particles, or sperm.

What distinguishes keratinized stratified squamous epithelium from the nonkeratinized variety?

Keratinized epithelium contains dead, scaly cells filled with keratin at its apical surface to prevent water loss and physical damage, whereas nonkeratinized epithelium consists entirely of living cells.

Where is keratinized stratified squamous epithelium located?

In the epidermis of the skin, being especially thick on the palms of the hands and soles of the feet.

Where is nonkeratinized stratified squamous epithelium found in the body?

In the tongue, cheeks (oral mucosa), esophagus, and the vagina after puberty.

What are the functions and locations of stratified cuboidal epithelium?

It secretes substances; located in sweat glands, ovarian follicles in the ovary, and seminiferous tubules in the testes.

What is urothelium (transitional epithelium) and where is it located?

A stretchable stratified epithelium whose cell shapes change as fluid builds up; it lines the entire urinary tract, including the ureter, urinary bladder, and urethra.