Lab 6

Question 1

Epithelial tissue

Answer 1

A tissue which:

• covers the body
• lines body cavities
• forms glands

Ex. Skin

Question 2

Connective tissue

Answer 2

A tissue which:

• binds and supports various organs

Ex. Blood

Question 3

Muscle tissue

Answer 3

A tissue which:

• contracts to create movement

Question 4

Nervous tissue

Answer 4

A tissue which:

• initiated and conducts electrochemical impulses

Question 5

Ectoderm

Answer 5

The outer germ layer of the embryo that gives rise to the outermost layer of the skin and nervous system.

Question 6

Endoderm

Answer 6

The inner germ layer of the embryo that gives rise to the mucous membranes of the digestive, respiratory, and urinary tracts (as well as digestive glands)

Question 7

Mesoderm

Answer 7

The middle germ layer of the embryo that gives rise to a gelatinous tissue called mesenchyme, which, in turn gives rise to muscle, blood vessels and all connective tissues.

Question 8

Apical surface

Answer 8

In an epithelial cell, the apical surface faces the external body surface, a body cavity, the inside of an internal organ, or a tubular duct that receives cell secretions.

Question 9

Basal surface

Answer 9

In the epithelial cell, the basal surface is the opposite of the apical surface (it faces the inside compartment of the organism)

Question 10

2 criteria used to classify epithelial tissue

Answer 10

1. Number of cell layers
   - determines simple or stratified
2. Shape of the cells at the apical surface
   - determines squamous, cuboidal, columnar

Question 11

Simple squamous epithelium

Answer 11

Consists of a single layer of flattened cells. (Note: cells are nearly transparent)

Body location examples:
- heart lining
- blood vessel lining
- kidneys

Function examples:
- in the kidneys it functions in diffusion and filtration
- in the lungs, it functions to allow diffusion of respiratory gases

Question 12

Simple cuboidal epithelium

Answer 12

Consists a single layer of box-shaped cells. Nucleus is near the centre of the cell

Body location examples:
- thyroid gland
- kidney tubules
- gland ducts

Function example:
- secretion and absorption

Question 13

Simple columnar epithelial

Answer 13

Contains rectangular cells that are very packed together. The nucleus is towards the base and appears more oval-shaped. Contains goblet cells.

Body location examples:
- stomach lining
- small/large intestine lining
- various gland ducts

Function examples:
- secretion and absorption

Question 14

Pseudostratified columnar epithelium

Answer 14

Consists of a single layer of columnar cells of various heights/shapes. Nuclei are staggered, which creates the impression of being stratified (even though it isn’t).

Body location examples:
- nasal cavity lining
- trachea lining

Function example:
- secretion and protection
- goblet cells produce mucus to trap inhaled particles

Question 15

Stratified squamous epithelialum

Answer 15

Composed of several layers of flattened cells (get taller towards basal surface), the # of cells and their thickness varies in different parts of the body

Body location examples:
- The skin (if keratinized )
- Lining of mouth of esophagus (if nonkeratinized)

Function example:
- protect against mechanical stress
- go through mitosis to produce new cells constantly

Question 16

Transitional epithelialum

Answer 16

Contains stratified cells that change in thickness, depending on the pressure against them. It is usually seen as having dome-shaped cuboid cells.

Body location examples:
- lining of urinary bladder, ureters, and urethras

Function example:
- allows urinary organs to accommodate to changing pressures without it rupturing.

Question 17

Merocrine glands

Answer 17

Glands that release their fluid products via exocytosis.

Ex. Salivary glands, sweat glands

Question 18

Apocrine glands

Answer 18

Glands that pinch off portions of the cell as part of the secretion.

Ex. Mammary glands

Question 19

Holocrine glands

Answer 19

When whole cells filled with the secretion are released.

Ex. Sebaceous glands

Question 20

What are the 3 structural features common to all connective tissue?

Answer 20

1. Cells
2. Protein fibres
3. Ground substance

(Note: protein fibres and ground substance come together to form the extracellular matrix)

Question 21

Areolar Connective tissue

Answer 21

Contains collagen and elastic fibers, arranged randomly to form a “loose” network within the ground substance. Also contains mass cells, fibroblasts, and macrophages.

Body location examples:
- underneath epithelial layer

Function example:
- attach skin to underlying tissue
- fills space between organs to hold them in place
- supports blood vessels

Question 22

Reticular connective tissue

Answer 22

Contains fibroblasts, white blood cells, and reticular fibers. Reticular fibres are short, thin, branched networks of collagen-like fibers.

Body location examples:
- spleen
- liver
- bone marrow
-lymph nodes

Function example:
- forms the internal framework of several organs

Question 23

Adipose connective tissue

Answer 23

Contains large lipid droplets, which forces the cytoplasm to shape into thin lines of surrounding the droplets. The nucleus is forced to the edge of the cell.

Body location examples:
- under the skin
- around kidneys, heart, eyeballs
- within the abdomen and breasts

Function example:
- synthesis and storage of lipids
- cushions regions of the body (shock absorption)
- regulate body temp

Question 24

Dense regular connective tissue

Answer 24

Contains bundles of collagen fibres organized in a parallel pattern. Fibroblast are found in rows between the collagen fibers.

Body location examples:
- ligaments
- tendons

Function example:
- resist pulling forces
- attach muscle to bone

Question 25

Perichondrium

Answer 25

A layer of dense connective tissue that surrounds most types of cartilage. It consists of an outer layer of collagen fibres (in an irregular pattern), and an inner layer of of collagen mixed with ground substance which forms chondrobladts. In between are cells and blood vessels

Question 26

Hyaline cartilage

Answer 26

Contains two layers of perichondrium, and in between it holds the matrix and the chondroblasts/cytes. **Body location examples:** - articular surface of bones - ends of the ribs - larynx - trachea **Function examples:** - gives support with some flexibility - helps joints maintain their shape

Question 27

Elastic cartilage

Answer 27

Contains the same basic structure as hyaline cartilage, but the matrix is full of elastic fibres. **Body location examples:** - external ear (pinna) - epiglottis - wall of auditory tube **Function examples:** - allows for lots of flexibility - supports its body locations

Question 28

Fibrocartilage

Answer 28

Lacks perichondrium, the chondrocytes are scattered between bundles of collagen fibers. The matrix is dominated by the mass of amounts of collagen fibers. **Body location examples:** - vertebral discs **Function examples:** - provides strong support - can withstand heavy pressure