Chapter 4- Tissues

Question 1

Histology is:

Answer 1

The study of tissues.

Histos= tissue
Logos= study

Question 2

The 4 basic types of tissues:

Answer 2

• Epithelial tissue
• Connective tissue
• Muscle tissue
• Nervous tissue

Question 3

Ocular lenses:

Answer 3

Magnify 10x

Question 4

The 4 objective lenses on the compound microscope:

Answer 4

1st objective - magnifies 5x (red ring)
2nd objective - magnifies 10x (yellow ring)
3rd objective - magnifies 40x (blue ring)
4th objective - magnifies 63x (silver)

Question 5

Human are made of:

Answer 5

Eukaryotic cells; all other cells are called Prokaryotic cells (bacteria).

Question 6

Epithelium:

Answer 6

A sheet of cells that covers a body surface or lines a body cavity.

Epi= upon 
Theleo= to grow

Question 7

The functions of epithelium include:

Answer 7

• Protection (of underlying tissues)
• Secretion (release of molecules from cells)
• Absorption (bringing small molecules into cells)
• Diffusion (movement of molecules down their concentration gradient)
• Filtration (passage of small molecules through a sieve-like membrane)
• Sensory reception

Question 8

Classification of epithelial tissue is based on 2 basic criteria:

Answer 8

• The number of layers

- The morphology (shape) of cells

Question 9

Simple epithelia:

Answer 9

Contains a single layer of cells, with each cell attached to the basement membrane.

Question 10

Stratified epithelia:

Answer 10

Contains more than one layer of cells. The cells on the basal surface are attached to the basement membrane; those on the apical surface border an open space.

Question 11

Types of cell morphology:

Answer 11

Squamous = flat, scale-like

Cuboidal = look like square from the side. Width and height are similar

Columnar = like a column from the side. Cells are tall and thin

Question 12

Squamous cells:

Answer 12

Flat cells with flat, disc-shaped nuclei

Question 13

Cuboidal cells:

Answer 13

Cube-shaped cells with spherical, centrally located nuclei

Question 14

Columnar cells:

Answer 14

Taller than they are wide. The nuclei are located near the basal surface and are commonly oval shaped.

Question 15

Simple squamous epithelium:

Answer 15

Single layer of flat cells

Very thin usually quite porous

Functions: diffusion, filtration, make smooth surface

Location: lines sacs of lungs (alveoli), lines blood vessels, lining of body cavities, lines renal capsules, lining of heart, lining of lymphatic vessels. Serous membrane (plus connective tissue)

Question 16

Simple cuboidal epithelium:

Answer 16

Simple layer of cuboidal cells

Function: diffusion, filtration, make smooth surface

Location: Forms the secretory cells of many glands, and the walls of the smallest ducts of glands, and the walls of many tubules in the kidney.

Question 17

Simple columnar epithelium:

Answer 17

Single layer of columnar cells.

Taller than they are wide.

Function: propels what is on top of the cilia

Location: lines oviduct (ciliated), respiratory tract (ciliated), digestive tract (microvilli)

Question 18

Cilia:

Answer 18

Hair-like, motile structures that extend from the free surfaces.

Made up of microtubules.

Important for removing products outside the cell.
E.g., mucus + anything trapped in the respiratory tract; the egg in the oviduct of the female.

Question 19

Microvilli:

Answer 19

Finger-like, non-motile extensions of the cells free surfaces (surface exposed to lumen or an organ)

Increase the surface area of a cell, more common in areas that are involved in absorption
(E.g., digestive tract and proximal convoluted tubules of kidney)

Question 20

Non-ciliated Simple Columnar:

Answer 20

Single layer of columnar cells.

Function: absorption

Location: stomach- large and small intestine, gall bladder, some glands

Question 21

2 types of stratified squamous epithelium:

Answer 21

Non-keratinized (less keratin)

Keratinized (a lot of keratin)

Both gives protection, but keratinized gives more.

Question 22

Keratin:

Answer 22

A protein that forms a scaffolding inside the cell giving lots of structural strength to the cell.

Dead cells, no nucleus.

Located: skin

Question 23

Non-keratinized:

Answer 23

Live cells, nuclei and mucous present.

Located: in mouth, esophagus, vagina, anal canal

Question 24

Pseudostratified columnar epithelium:

Answer 24

A single layer of cells that appear to be multilayered.

Nuclei are located at different heights, but all cells touch the basement membrane.

Functions: secretion and absorption

Located in trachea.

Identified by the presence of cilia and Goblet cells.

Question 25

Stratified cuboidal epithelium:

Answer 25

Rare.

2-3 layers of cuboidal cells.

Located in large ducts of some glands.
(Ex: sweat glands, mammary glands, and salivary glands.

Question 26

Stratified columnar epithelium

Answer 26

Rare.

2-3 layers of cells being the most superficial cells columnar in shape.

Location: parts of larynx, pharynx (throat), ducts of some glands, and small amounts of the male urethra.

Question 27

Transitional epithelium:

Answer 27

Unique tissue.

Stretches.

Found in urinary bladder, ureter/urethra.

Transitions from squamous to cuboidal. Dome-shaped cells with heavy coloring.

Question 28

Define tissue:

Answer 28

A group of cells of similar structure that perform a common function.