Vtt235 A&p Integumentary System

Front 1

Four primary types of tissues

Back 1

Epithelial
Connective
Muscle
Nervous

Front 2

What does epithelial tissue do?

Back 2

Covers and lines other tissues
Protects underlying tissues and may act to filter biochemical substances
May absorb, secrete or excrete biochemical substances (hormones, sweat, ions)
May play a role in the reception of sensory input

Front 3

Each epithelial cell has an apical and basal surface. What is the apical surface?

Back 3

The surface that faces the lumen or outside of the organ (skin faces the outside world)

Front 4

Each epithelial cell has an apical and basal surface. What is the basal surface?

Back 4

The surface that faces the basal lamina and blood vessels

Front 5

Epithelial cells are avascular, what does this mean?

Back 5

They don't have thier own blood supply, but interact close enough to benefit

Front 6

Lateral sides of epithelial cells are connected by junctional complexes, what are the three most major junctions and their description?

Back 6

Tight Junctions:
Formed by the fusion of the outermost layers of the plasma membranes of adjoining cells.
Found in tissues in which there can be no leaks (urinary bladder, digestive tract)

Desmosomes:
Mechanical coupling formed by the filaments that interlock with one another.
Found in tissues that undergo repeated episodes of tension and stretching (skin, heart, uterus)
Gap Junctions:
Tubular channel proteins (connexons) that extend from the cytoplasm fo one cell to the cytoplasm of another
Allows exchange and passage of ions and nutrients
Found in intestinal epithelial cells, the heart, and smooth muscle tisse (intestine, stomach)

Front 7

What is the basement membrane?

Back 7

A meshwork of fibers that cements the epithelial cell to the underlying connective tissue

Front 8

What else is the basement membrane called?

Back 8

Basal lamina + reticular lamina

Front 9

What does the basement membrane do?

Back 9

Helps prevent the cell from being torn off by intraluminal pressures
Acts as a partial barrier between the epithelial cell and the underlying connective tissue

Front 10

Squamous epithelium

Back 10

Squamous cells have the appearance of thin, flat plates. They fit closely together in tissues; providing a smooth, low-friction surface over which fluids can move easily. The shape of the nucleus usually corresponds to the cell form and helps to identify the type of epithelium. Squamous cells tend to have horizontally flattened, elliptical (oval or shape like an egg) nuclei because of the thin flattened form of the cell. Classically, squamous epithelia are found lining surfaces utilizing simple passive diffusion such as the alveolar epithelium in the lungs. Specialized squamous epithelia also form the lining of cavities such as the blood vessels (endothelium) and heart (mesothelium) and the major cavities found within the body.

Front 11

Cuboidal epithelium

Back 11

As their name implies, cuboidal cells are roughly cuboidal in shape, appearing square in cross section. Each cell has a spherical nucleus in the centre. Cuboidal epithelium is commonly found in secretive or absorptive tissue: for example the (secretive) exocrine gland the pancreas and the (absorptive) lining of the kidney tubules as well as in the ducts of the glands. They also constitute the germinal epithelium, which produces the egg cells in the female ovary and the sperm cells in the male testes.

Front 12

Columnar epithelium

Back 12

Columnar epithelial cells are elongated and column-shaped. Their nuclei are elongated and are usually located near the base of the cells. Columnar epithelium forms the lining of the stomach and intestines. Some columnar cells are specialized for sensory reception such as in the nose, ears and the taste buds of the tongue. Goblet cells (unicellular glands) are found between the columnar epithelial cells of the duodenum. They secrete mucus, which acts as a lubricant.

Front 13

Pseudostratified epithelium

Back 13

These are simple columnar epithelial cells whose nuclei appear at different heights, giving the misleading (hence "pseudo") impression that the epithelium is stratified when the cells are viewed in cross section. Pseudostratified epithelium can also possess fine hair-like extensions of their apical (luminal) membrane called cilia. In this case, the epithelium is described as "ciliated" pseudostratified epithelium. Cilia are capable of energy dependent pulsatile beating in a certain direction through interaction of cytoskeletal microtubules and connecting structural proteins and enzymes. The wafting effect produced causes mucus secreted locally by the goblet cells (to lubricate and to trap pathogens and particles) to flow in that direction (typically out of the body). Ciliated epithelium is found in the airways (nose, bronchi), but is also found in the uterus and Fallopian tubes of females, where the cilia propel the ovum to the uterus.

Front 14

Transitional epithelium

Back 14

Stratified epithelium with a basal layer of cuboidal or columnar cells and a superficial layer of cuboidal or squamous cells
Found in areas of the body required to expand and contract as part of their normal function

Front 15

Glandular epithelium

Back 15

Groups of cells that manufacture and discharge a secretion

Front 16

Endocrine Glands

Back 16

Glands that do not have ducts or tubules and whose secretions are distrubuted throughout the body
Produce and secrete hormones into the bloodstream or the lymphatic system
Park of a complex, biochemical network known as the endocrine system

Front 17

Exocrine Glands

Back 17

Discharge secretions via ducts directly into local areas (except for goblet cell)
Unicellular or multicellular
Sweat, salivary, mammary glands, etc.

Front 18

Glandular epithelium

Back 18

Groups of cells that manufacture and discharge a secretion

Front 19

Endocrine Glands

Back 19

Glands that do not have ducts or tubules and whose secretions are distrubuted throughout the body
Produce and secrete hormones into the bloodstream or the lymphatic system
Park of a complex, biochemical network known as the endocrine system

Front 20

Exocrine Glands

Back 20

Discharge secretions via ducts directly into local areas (except for goblet cell)
Unicellular or multicellular
Sweat, salivary, mammary glands, etc.