Tissues of the body L1.1

Question 1

Define histology

Answer 1

Study of tissues

Question 2

State the 4 fundamental tissue types

Answer 2

1. Epithelial tissue
2. Muscle tissue
3. Nervous tissue
4. Connective (support) tissue

Question 3

Define tissue

Answer 3

Functional arrangement of cells

Question 4

State a function of membranes

Answer 4

Allow compartementalisation

Question 5

State the most prominent cell structure

Answer 5

1. Nucleus

Question 6

State function of nucleus

Answer 6

Stores genomic DNA
Site of mRNA trasncrption
Contains NUCLEOLOS - site of RNA synthesis + initial assembly of ribosomes

Question 7

State functions of nucleolus

Answer 7

1. RNA synthesis
2. Initial assembly of ribosomes

Question 8

Describe the structure of the nucleus

Answer 8

1. Nucleolus
2. Stores genomic DNA
3. Surrounded by nuclear envelope (double membrane) continuous with RER
4. Supported by network of intermediate filaments

Question 9

Which cells have an abundance of RER?

Answer 9

Biosynthetic cells (pancreatic, acinar)

Basophilic RER stains are vert strong with basic dyes (e.g. haematoxylin)

Question 10

Describe the structure of the RER

Answer 10

Continuous with nuclear envolope

Question 11

Histology of pancreatic acinar cell clusters

Answer 11

Question 12

Describe the composition of ribosomes

Answer 12

rRNA
75 distinct proteins

Question 13

Describe the function of ribosomes

Answer 13

Catalyse protein synthesis
(large (60s) + small (40s) subunits associate when bound to mRNA in order to catalyse protein synthesis

Question 14

State the function of free polyribosomes (polysomes)

Answer 14

Synthesis of structural, nuclear, peroxisomal, mitochondrial proteins which stay within the cell

Question 15

State the function of membrane-bound ribosomes

Answer 15

Syntyhesis of membrane lyososomal proteins
Synthesis of proteins to be secreted

Question 16

Describe the structure of SER

Answer 16

Smooth Endoplasmic Reticulum

Not associated with ribosomes

Question 17

Where is SER abundant ?

Answer 17

Liver (lipid biosynthesis)
Mammary gland (in lipid biosynthesis)
Ovary
Testis
Adrenal glands (steroidogenesis)
Muscle (storages Ca2+)

Question 18

Histology of pancreatic acinar cell

Answer 18

Question 19

State 3 functional parts of golgi apparatus

Answer 19

1. Cis face - nuclear facing
2. Medial golgi: central
3. Trans golgi network

Question 20

State the role of the specific coat protein within golgi apparatus

Answer 20

Tagged on golgi apparatus
Targets vesicles to correct compartment

Question 21

Histology of Golgi Apparatus

Answer 21

Question 22

Histology of Golgi Apparatus

Answer 22

Question 23

State main types of cell vesicles

Answer 23

1. (Cell surface-derived) endocytotic vesicles (e,g, phagocytotic)

2.( Golgi derived) transport + secretory vesicls

3.( ER derived) transport vesicles

4. lysosomes
5. Peroxisomes

Question 24

Where are lysosomes derived from?

Answer 24

Golgi Appartus

Question 25

How is the membrane of the lysosome not dissolved by H+ actively pumped from cytosol into lysosome?

Answer 25

Highly glycosylated membrane proteins Protect membrane from the action of hydrolytic enzyme - vacuolar ATPase This enzyme actively pumps H+ across membrane to maintain acidic pH for the acidic hydrolases (nuclease, proteases etc)

Question 26

State the role of membrane proteins in the membrane of the lysosome

Answer 26

Highly glycosylated membrane proteins Protect membrane from the action of hydrolytic enzyme - vacuolar ATPase This enzyme actively pumps H+ across membrane to maintain acidic pH for the acidic hydrolases (nuclease, proteases etc)

Question 27

What is Autophagy ?

Answer 27

Self-Eating 1. Lysosomal breakdown of non-functioning organelles / cellular components 2. (Homeostatic process) to prevent accumulation of damaged components in cell 3. The digested products are recycled

Question 28

Describe the process of autophagy

Answer 28

1. Organelle engulfed by region of SER to form autophagosome, which fuses with lysosome

Question 29

Describe how tumour cells use autophagy

Answer 29

To recycle substrates Therefore, inhibition of autophagy can prevent cancer (inhibts the recycling of substrates)

Question 30

Histology of phagolyososome

Answer 30

Question 31

Give an example of a substance that cannot be reused after the autophagy process

Answer 31

Residual bodies - Remnants of phagolysosomes containing indigestible material (can form lipofuscin granules) as we age, increased amount of residual bodies in our body