L3&4. Cells And Tissues

Question 1

Define tissue

Answer 1

Groupings of cells with similar morphology that perform a particular function

Question 2

Define organ

Answer 2

Group of tissues that perform a particular function

Question 3

Define system

Answer 3

Group of organs that work together to perform a specific function

Question 4

Name the 4 components of blood

Answer 4

Plasma
Erythrocytes = RBC
Leukocytes = WBC
Platelets

Question 5

4 Functions of connective tissue

Answer 5

Binds cells an organs together
Provides structural support
Contains blood vessels and tissue defence mechanisms
Important in tissue repair

Question 6

What is the ECM

Answer 6

Major component of connective tissue
Made of protein fibres in a hydrated carbohydrate rich gel
In vivo all cells are in contact with it
Carries a machanicak load

Question 7

What is the difference between plant and animal ECM composition

Answer 7

Plant comtains cellulose

Question 8

Describe the structure of collagen

Answer 8

Triple helices
Rich in proline and glycine
Synthesised as pro alpha chains
Can associate outside of the cell forming fibrils and fibres (covalent cross links between molecules)

Question 9

What is the function of collagen

Answer 9

Tensile strength

Structural support

Question 10

What is the structure of elastin

Answer 10

Contains proline and glycine
Molecules form cross links = fibres
Microfibrils cover the elastin core

Question 11

What is the function of elastin

Answer 11

Allows cells to reform their dhape after being stretched

Question 12

What is the structure of fibronectin

Answer 12

Large non collagenous glycoprotein
2 subunits linked by disulfide bonds
Binds to the cell surface by the Arg-Gly-Asp tripeptide

Question 13

What is the function of fibronectin

Answer 13

Bind to the ECM to the cell surface

Question 14

What is the structure of GAGs

Answer 14

Unbranched polysaccharide
High negative charge from S and OH groups
Repeat units of amino sugar and Uronic acid

Question 15

How is the ECM synthesised

Answer 15

By the cell in it

Eg. Cartalige contain chondoblasts that secrete the ECM

Question 16

How is the ECM degraded

Answer 16

Locally by extra cellular proteases

Question 17

Give 2 examples of proteases that degrade the ECM

Answer 17

Metalloproteases and serine proteases

Question 18

How is ecm degradation controlled

Answer 18

Proteases are secreted as inactive precursors and tvhen activated by protein modification
Protease inhibitors can block secretion

Question 19

How do cells binds to other cells

Answer 19

Integrins

Question 20

What are integrins

Answer 20

Cell surface receptors
Transmembrane glycoprotein that link cytoskeleton to the ECM
Located in cell-matrix junctions

Question 21

What is the structure of integrins

Answer 21

2 non covalently bonded sub units

Question 22

What are syndecans

Answer 22

Co receptors

Cell surface proteoglycans

Question 23

What are the functions of the ECM

Answer 23

1. Provide structural support
2. Aid cell migration (basement membrane)
3. Bind peptide growth factors
4. Integrins inform the cell about their environment

Question 24

Function of epithelial tissue

Answer 24

Protect lower surfaces from physical damage and UV radiation
Absorption and secretion

Question 25

Define simple epithelia

Answer 25

1 layer

Question 26

Define stratified epithelia

Answer 26

1+ layer of cells

Question 27

Define pseudostratified epithelia

Answer 27

Mono layer but cells have nuclei at different heights

Question 28

Define squamous epithelia

Answer 28

Fiat

Question 29

Define cuboidal epithelia

Answer 29

Square shaped

Question 30

Define columnar epithelia

Answer 30

Rectangular (height>width)

Question 31

Define translational epithelia

Answer 31

Change height depending on if it’s stretched or relaxed

Question 32

Function of simple epithelia

Answer 32

Diffusion and absorbance

Question 33

Example of where simple epithelia is found

Answer 33

Alveoli | Intestine

Question 34

What is the function of stratified epithelia

Answer 34

Protection

Question 35

Where is stratified epithelia found

Answer 35

Skin

Question 36

What is an occluding junction

Answer 36

Seals spaces Between cells Prevent leakage of water soluble substances Maintain cell polarity

Question 37

What proteins are used in occluding junctions

Answer 37

Occluding and Claudin

Question 38

What are communicating junctions

Answer 38

Allow communication between cells Intercellular channels Allow diffusion of ions

Question 39

What are anchoring junctions

Answer 39

Connect cytoskeleton of adjacent cells | Give mechanical strength

Question 40

What are the 2 types of anchoring junctions

Answer 40

Adherens and desmosomes

Question 41

What are the 3 types of muscle

Answer 41

Skeletal, smooth and cardiac

Question 42

Function of skeletal muscles

Answer 42

Body movement

Question 43

Type of cells in skeletal muscle

Answer 43

Elongated Multinucleated Myofibrils

Question 44

Function of smooth muscle

Answer 44

Apply pressure to vessels and organs

Question 45

What type of cells are in smooth muscle

Answer 45

Mononucleated Small cells Branched and irregular fibre bundles No cross striations

Question 46

What types of cell is in cardiac muscle

Answer 46

Long 1/2 nuclei per cell Striations A little branched

Question 47

What does PNS stand for

Answer 47

Pereipheral nervous system

Question 48

What does somatic stand for

Answer 48

Voluntary

Question 49

What does autonomic mean

Answer 49

Involuntary

Question 50

What are glial cells

Answer 50

Support and protection cells | Receive no electrical impulses

Question 51

What is grey matter

Answer 51

Neurone cell body + axons

Question 52

What is white matter

Answer 52

Myelinated nerve fibres