Primary Tissues

Question 1

Process of differentiation

Answer 1

• Expression of different gene subsets –> different protein expression
• Affects structure & function

Question 2

Originator cell

Answer 2

Stem cell - first cell in the differentiation process

Question 3

Define tissue

Answer 3

A group of specialised cells with a distinct function

Question 4

Define organ

Answer 4

A group of specialised organs with a certain function

Question 5

4 body tissues

Answer 5

• Epithelia
• Connective tissue
• Muscle
• Nervous tissue

Question 6

Define epithelia

Answer 6

Covers and lines surfaces and body cavities - enclosing a sheltered environment

Question 7

Define connective tissue

Answer 7

Fibrocollagenous tissue - consists of fibres, cells & extracellular matrix

Question 8

Define muscle

Answer 8

Contractile tissue - contracts under voluntary or involuntary control

Question 9

Define nervous tissue

Answer 9

Collects, processes and sends info through neuron network –> to create a response

Question 10

Functions of epithelia x4

Answer 10

• Secretion
• Absorption
• Transport
• Protection

Question 11

4 epithelial junctions & their function

Answer 11

• Tight junctions –> sealing
• Desmosomes –> strengthens cell links
• Gap junctions –> small molecules can pass between cells
• Adherens junctions –> connection linking actin

Question 12

Burns

• what
• dangers

Answer 12

• Loss of skin barrier function

- Infection, fluid loss

Question 13

Basement membrane

- features x2

Answer 13

• Proteins –> links to surface of epithelial cells

- Filamentous proteins –> strength

Question 14

Neurons

• structure x3
• function

Answer 14

• elongated cells
• dendrites –> basal, collect info
• axon –> apical, single digital output
• secrete neurotransmitters by exocytosis

Question 15

Myelination - in PNS

Answer 15

Schwann cells wrap around neurones to produce the fatty sheath

Question 16

Myelination - in CNS

Answer 16

Oligodendrocytes (glial cells) produce the fatty sheath

Question 17

4 types of glial cells

Answer 17

• Schwann cells
• Satellite cells
• Astrocytes
• Microglial cells

Question 18

Astrocytes

• what
• function
• white vs grey matter

Answer 18

• Star-like fibular proteins
• Metabolic support –> attach to & maintain endothelium
• Grey = ‘blobby’, white = more strung out

Question 19

Microglial cells

• what
• function

Answer 19

• Macrophage

- Engulfs pathogens, synapses, dead cells etc.

Question 20

3 types of muscle

Answer 20

• Skeletal
• Cardiac
• Smooth

Question 21

Skeletal muscle

Answer 21

Striated, multinucleate, coordinated contraction = mostly voluntary.
Fibres have peripheral nuclei

Question 22

Cardiac muscle

Answer 22

Striated, coordinated contraction, involuntary, branched 
Junctions - e.g. intercalated discs
Central nuclei (as wide as cell)

Question 23

Smooth muscle

Answer 23

Non-striated, coordinated contraction, involuntary, spindle shaped –> hard to see cell boundaries
Not much cytoplasm
Central nuclei

Question 24

Examples of connective tissue x4

Answer 24

• Cartilage
• Bone
• Teeth
• Adipose tissue

Question 25

2 functions of fibrocartilagenous / fibrocollagenous tissue

Answer 25

Packing, support tissues e.g. around organs

Question 26

3 types of fibrocartilaginous tissue

Answer 26

- Loose - Dense - Reticular

Question 27

Structure - loose connective tissue x3

Answer 27

- Lots of cells - Collagen - Spaces occupied by proteoglycans

Question 28

Structure - dense connective tissue x3 (& example)

Answer 28

- Packed - Collagen - Less spaces - e.g. tendons

Question 29

Structure - reticular connective tissue x2 (& example)

Answer 29

- Soft framework - Support - e.g. liver

Question 30

Cells in fibrocartilaginous tissue (& their function) x4

Answer 30

- Fibroblasts --> make collagen - Macrophages --> phagocytose - Mast cells --> synthesise histamine - Plasma cells --> synthesise antibodies

Question 31

Cartilage - function - 3 types

Answer 31

- Flexibility, smooth joint movement | - Elastic, hyaline, fibrocartilage

Question 32

Elastic cartilage

Answer 32

Flexible (as contains elastin)

Question 33

Hyaline cartilage

Answer 33

- Low friction, durable | - Contains chondrocytes & lots of cytosol

Question 34

Fibrocartilage

Answer 34

Strong (as contains collagen)

Question 35

Adipose tissue - white fat - structure - function x2

Answer 35

- One lipid droplet occupies most of the cell - Stores energy - Releases leptin

Question 36

Adipose tissue - brown fat - structure - function

Answer 36

- Contains multiple fat globules | - Generates heat (instead of ATP)

Question 37

Dorsal horn cells - what - structure x2 - function

Answer 37

- Biggest neurons - V long processes - Satellite cells around edge - Proprioception (detecting position in space)

Question 38

Axons vs dendrites

Answer 38

- Axons contain less organelles | - Axons stay the same size --> dendrites decrease away from the cell

Question 39

Axon hillock - appearance in histology - function

Answer 39

- Paler - as lacks Nissl substance | - Axon potential generation

Question 40

Myelin & histology

Answer 40

- Rapid freezing used (not embedding) - as myelin is rich in membrane

Question 41

Structure - fibroblasts x2

Answer 41

- Lots of rER (for secretion of fibrous proteins) | - At surface, processes = continuous w fibres

Question 42

Structure - macrophages x1

Answer 42

Derived from monocytes = differentiated into phagocytes

Question 43

Structure - mast cells x1

Answer 43

Contain granules (modified secretory lysosomes) --> contain histamine, heparin

Question 44

Structure - plasma cells x3

Answer 44

- B cell lymphocytes - Small round nucleus w a lot of cytoplasm - Have differentiated to be antibody-secreting

Question 45

Structure - adipose tissue x2

Answer 45

- Originate from fibroblast-like precursors | - Accumulate lipid droplets --> therefore, thin cytoplasm