Histology

Question 1

What are the 3 classes of filaments

Answer 1

Microfilaments, Intermediate filaments and Microtubules

Question 2

What are microfilaments made of

Answer 2

Actin

Question 3

What are microtubules made of

Answer 3

Two tubulin subunits; Alpha and Beta

Question 4

What proteins attach to microtubules and serve as the ‘motorway network of cell’

Answer 4

Dynein and Kinesin; both are ATPase
Dynein moves toward cell centre
Kinesin moves away from cell centre

Question 5

Location of synthesis of RNA in a cell

Answer 5

mRNA and tRNA - Transcribed in Nucleus

rRNA - Transcribed in Nucleolus

Question 6

Differentiate Euchromatin and Heterochromatin

Answer 6

Euchromatin - Actively undergoing transcription, light grainy colour, unwound
Heterochromatin - Condensed, wound, not transcripting

Question 7

Role of Smooth Endoplasmic Reticulum

Answer 7

Process proteins produced in RER

Synthesis of lipids

Question 8

3 types of intercellular junctions

Answer 8

Occluding junctions - Zona Occludends/Tight junctions, prevent diffusion
Anchoring junctions - Zone Adherens/Adherent junctions
Macula Adherens - Desmosomes, common in skin to provide mechanical stability
Communicating junctions - Gap junctions; have connexon protein; heart and smooth muscle to spread excitation

Question 9

Common stain in preparing slides

Answer 9

Haematoxylin and Eosin - Stains acidic molecules like DNA purplish blue and stains basic molecules like plasma proteins pinkish red

Question 10

4 basic tissue types

Answer 10

Epithelium, muscle, nervous and connective

Question 11

Types of connective tissue

Answer 11

Soft - Tendons, ligaments, epidermids
Hard - Bone and cartilage
Blood and lymph - Specialized form

Question 12

Types of soft connective tissue

Answer 12

Loose soft connective tissue - Loosely packed fibres separated by abundant ground substance
Dense soft connective tissue - Densely packed bundles of collagen fibres; regular or irregular

Question 13

Types of bone

Answer 13

Outer shell of dense cortical bone - Diaphysis

Cancellous or trabecular bone - Epiphyses

Question 14

Types of cardiac muscle

Answer 14

Smooth, skeletal and cardiac

Question 15

What ‘coat’ covers nervous tissue

Answer 15

Meninges in CNS

Epineurium in PNS

Question 16

Types of neurons

Answer 16

Multipolar - Many dendrites, one axon
Bipolar - One dendrite, one axon
Pseudounipolar - Short processes, axon in both direction

Question 17

Types of Glia

Answer 17

CNS - 
Astrocytes - Support, ion transport, induce blood brain barrier
Oligodendrocytes - Produce myelin 
Microglia - Immune surveillance 
Schwaan Cells - Myelin in PNS

Question 18

Major salivary glands

Answer 18

Parotid - More serous secreting cells
Submandibular - Equal number of cells
Sublingual - More mucus secreting cells

Question 19

Function of striated ducts in salivary glands

Answer 19

The ducts pump salt out of the fluid so that it’s hypotonic to blood

Question 20

4 parts of the digestive tract

Answer 20

From lumen out -
Mucosa - Epithelium, lamina propria, muscularis mucosae
Submucosa
Muscularis externa - Inner circular and outer longitudinal layer of smooth muscle
Serosa or Adventitia

Question 21

What is the enteric nervous system?

Answer 21

The digestive tract has its own nervous system called Enteric nervous system

Question 22

Basic structure of the liver

Answer 22

Liver is made up of a large number of lobules. Each lobe has liver cells called hepatocytes. Each corner has a hepatic portal vein and hepatic artery. Central vein in the centre drains to these via Hepatic sinusoids.

Question 23

What is the portal triad?

Answer 23

The hepatic portal vein + Hepatic artery + Bile duct

Question 24

Endocrine vs exocrine glands

Answer 24

Exocrine glands release their products via ducts or into the lumen/ body surface
Endocrine glands release their products towards the basal laminae into capillaries (no ducts)

Question 25

3 layers of blood vessels

Answer 25

From lumen to out -
Tunica Intima - Simple squamous epithelium
Tunica Media - Smooth muscle
Tunica Adventitia - Connective tissue

Question 26

What are elastic arteries

Answer 26

The major arteries such as the aorta have many sheets of elastic fibres in tunica media to provide elastic recoil

Question 27

What is vasa vasorum

Answer 27

Elastic arteries have their own vascular supply termed vasa vasorum

Question 28

Compare diameter of RBCs and capillaries

Answer 28

RBC - 7 micron, Capillaries - 4 to 8 micron

Question 29

3 types of capillaries

Answer 29

Continuous - Muscle, lungs, skin
Fenestrated - Gut, endocrine glands, kidney
Discontinuous or Sinusoidal - Liver, spleen, marrow

Question 30

Which vessels are important sites for exchange

Answer 30

Post - Capillary Venules

Question 31

What is the buffy coat found after blood has been spun in a centrifuge?

Answer 31

The buffy coat consists of leukocytes and platelets

Question 32

What organ removes aged RBC ( > 4 months)

Answer 32

Spleen and liver

Question 33

Histological appearance of Neutrophils

Answer 33

Don’t stain with acidic or basic dyes, multi-lobed

Question 34

Histological appearance of Eosinophils

Answer 34

Affinity for acidic red dye Eosin, bilobed nucleus

Question 35

Histological appearance of Basophils

Answer 35

Affinity for basic bluish purple Methylene blue, bilobed nucleus often obscured

Question 36

Histological appearance of Monocytes

Answer 36

Seem non-granulated, non lobulated nuclues, kidney bean shaped

Question 37

Histological appearance of Lymphocytes

Answer 37

Round nucleus, surrounded by thin to moderate rim of cytoplasm, non-granulated

Question 38

Embryological location of haematopoiesis

Answer 38

Liver and spleen to some extent