Diversity of Cells and Their Functions

Question 1

What are fixatives?

Answer 1

Used to preserve the structure of the tissue

Question 2

Why do we impregnate a tissue with parafin wax?

Answer 2

Gives structural integrity to the piece of tissue in a super thin slice so it can be viewed through a microscope.

Question 3

What is a Microtome?

Answer 3

Used for creating very thin slice of tissue for viewing under a microscope.

Question 4

Name the dyes H & E

Answer 4

Haematoxylin and Eosin

Question 5

What is Haematoxylin?

Answer 5

A Basic dye with an affinity for acidic molecules. (dyes tissue Purple)

Question 6

What is Eosin?

Answer 6

An acidic dye with an affinity for Basic molecules. (dyes tissue Pink)

Question 7

Name the 4 Basic Tissue types

Answer 7

• Epithelium
• Connective tissue
• Muscle
• Nervous tissue

Question 8

Describe the traits of Epithelium.

Answer 8

• Covers surfaces of the body, lines hollow organs, forms glands.
• Non-vascular
• Typically polarised (apical and basal sides differ)
• Large extracellular matrix components, “basal Lamina”

Question 9

Name the functions of Epithelium.

Answer 9

• Strong adhesion resulting in effective Mechanical Barrier.
• Chemical barrier (lining of stomach)
• Absorption (lining of intestines)
• secretion (salivary gland)
• Containment (urinary bladder)
• Locomotion (oviduct)

Question 10

Describe the shape classification of Epithelium.

Answer 10

Squamous - Flattened (fish scale)
Cuboidal - Cube
Columnar - Tall and thin

Question 11

Describe the layer classification of Epithelium.

Answer 11

Simple - One layer
Stratified - Two or more layers
Pseudostratified - Tissue appears to have multiple layers

Question 12

Name some of the specialised components of Epithelium tissue.

Answer 12

Cell/Tissue surface - Prominent microvilli, Cilia, keratinised.

Presence of specialised cell types - Goblet cells (single celled mucous glands)

Question 13

Describe Glandular Epithelia

Answer 13

Endocrine Glands - secrete at basal end of cell, trying to get product to enter bloodstream.
Exocrine Glands - secrete towards apical end of cell, trying to get product into a duct or onto body surface.

Question 14

Name and give examples for the 3 types of connective tissue.

Answer 14

Soft Connective Tissue - Tendons, ligaments, mesentery
Hard connective tissue - Bone and cartilage
Blood and lymph - Partially considered as a specialised type of connective tissue.

Question 15

What else does connect tissue consist of?

Answer 15

Extra cellular matrix.
Cells.
The type of connective tissue is determined by the types and relative amounts of these.

Question 16

What does the Extracellular matrix consist of?

Answer 16

Fibres: collagen, reticular and elastic fibres.
Ground substance: Amorphous space
occupying material, made of huge
unbranched polysaccharide molecules called
glycosaminoglycans (GAGs)
Tissue fluid

Question 17

What do the cells found in connective tissue consist of?

Answer 17

Fibroblasts: Widely distributed cells that produce and maintain the extracellular matrix.
Adipose cells: fat cells, found scattered among many connective tissues.
Osteocytes: Cells of bone
Chondrocytes: Cells of cartilage

Question 18

What are the two types of soft connective tissue?

Answer 18

Loose and Dense

Question 19

Describe the makeup of loose, soft connective tissue.

Answer 19

Loosely packed fibres separated by abundant ground substance.

Question 20

Describe the makeup of Dense, Soft connective tissue

Answer 20

Densely packed bundles of collagen fibres. Dense regular Connective Tissue if fibres are aligned (tendon) or dense irregular if fibre bundles run in many directions. (e.g. Dermis of the skin)

Question 21

Describe cartilage - Hard connective tissue.

Answer 21

Strong, flexible, compressible, semi rigid tissue.

-> semi rigid nature comes from highly hydrated nature of the ground substance (GAG’s and proteoglycans)

Question 22

What are the 3 types of cartilage?

Answer 22

Hyaline, elastic and fibrocartilage.

Question 23

Describe Bone - Hard connective tissue.

Answer 23

• Dense cortical outer-shell (diaphysis)

- Cancellous or trabecular bone occupies the ends of the bone. (the Epiphyses)

Question 24

what are the small canals that penetrate bone to supply it with blood vessels and nerves.

Answer 24

Haversian canals.

Question 25

What are the major types of muscle tissue?

Answer 25

Smooth, cardiac and skeletal.

Question 26

How is force produced in muscle tissue?

Answer 26

By the movement of actin fibres over myosin fibres.

Question 27

Describe smooth muscle.

Answer 27

(AKA involuntary or visceral) made up of long spindly cells. Called smooth due to the lack of visible striations.

Question 28

Describe Skeletal muscle

Answer 28

(AKA Voluntary or striated muscle).
Conscious control.
Multi-nucleated, cylindrical cell

Question 29

Describe Cardiac muscle?

Answer 29

Forms the wall of the heart. Cardiac muscle has striations.
Intercalated discs, can be seen passing across the fibres at irregular intervals. contain many intracellular junctions to maintain mechanical integrity.

Question 30

What is nervous tissue?

Answer 30

Contains neurons and glial support cells.

Nervous tissue is supported by a connective tissue coat. (meninges - CNS) (Epineurium - PNS)

Question 31

Describe Glia

Answer 31

Astrocytes: support and ion transport
Oligodendrocytes: Produce myelin
Microglia: Provide immune surveillance
Schwann cells (PNS): produce myelin and support axons