Chapter 4: tissues

Question 1

What are the 4 types of tissues?

Answer 1

Epithelial, Connective, nervous, and muscle

Question 2

Nervous tissue

Answer 2

Internal communication (brain/spinal cord/nerves)

Question 3

Muscle tissue

Answer 3

Contracts to cause movement
- Attached to bones (skeletal)
- Heart (cardiac)
- Walls of hollow organs (smooth)

Question 4

Epithelial tissue

Answer 4

Forms boundaries between environments, covers, protects, secretes, absorbs, filters
- Lining of GI tract organs + hollow organs
- Skin surface (epidermis)

Question 5

Connective tissue

Answer 5

Supports, protects, and binds other tissues together
- Bones
- Tendons
- Fat and other soft padding tissue

Question 6

What are the two things that epithelial tissue consists of? Define them

Answer 6

Epithelia: covers exposed surfaces and line internal cavities + passageways, often contain secretory cells/gland cells, scattered among other cell types

Glands: derived from epithelia, but secretory cells predominant

Question 7

What are the 2 types of glands?

Answer 7

Exocrine: secretes onto external surfaces or into internal passageways (ducts) that connect to the exterior

Endocrine: secrete hormones into interstitial fluid via distribution by bloodstream

Question 8

What are the 5 characteristics of epithelia

Answer 8

1. Polarity - apical/basal
2. Specialized contacts - intercellular junctions
3. Connective tissue support - basement membrane
4. Avascular but innervated (no blood supply but receives nutrients from tissues via diffusion)
5. Regeneration - rapid rate of division

Question 9

How many layers in a simple and stratified epithelium?

Answer 9

1 for simple epithelium (absorption/secretion/filtration)

> 1 for stratified (protection in high abrasion areas)

Question 10

What are the 3 simple epithelium cells?

Answer 10

1. Squamous flat: kidney, flattened cells, diffusion and filtration, air sacs
2. Cuboidal box: single layer cubelike, secretion/absorption, kidney tubules, ducts
3. Columnar tall: tall cells, some with cilia, goblet cells, absorption/secretion of mucus, and the cilia types will propel mucus, abdomen

Question 11

What are the 5 types of stratified tissues?

Answer 11

1. Pseudostratified columnar: single layer of cells differing heights, secretion of mucus, upper respiratory + trachea for ciliated and nonciliated for male sperm ducts, propels via ciliary
2. Stratified squamous: thick membrane and flattened, surface cell dead, basal cell active, protection, keratinized, esophagus + mouth + vagina
3. Stratified cuboidal: rare, sweat and mammary glands, 2 cell layers thick
4. Stratified columnar: limited, pharynx, male urethra, lining some mammary glands
5. Transitional: both squamous + cuboidal, basal = cuboidal, surface = squamous, stretches and permits stretching of urinary organ, ureters + bladder

Question 12

Glandular epithelia

Answer 12

gland is one/more cells that makes and secretes aqueous fluid

• Site of product release (endocrine/exocrine)
  unicellular/multicellular

Question 13

Unicellular exocrine glands

Answer 13

Only important unicellular gland is globet cell
- produce mucin –> mucus
- secreted via exocytosis

Question 14

Multicellular exocrine glands

Answer 14

composed of a duct + secretory unit
- structure: duct (simple) or structure of secretory units

Question 15

What are the 3 modes of secretion? define them

Answer 15

1. Merocrine (merely secrete): products are secreted by exocytosis (pancreas/sweat/salivary)
2. Holocrine: products are secreted by rupture of gland cells
3. Apocrine: pinches off secretion + repairs, controversial if found in humans (mammary)