Histology Flashcards
What are the 3 classes of filaments
Microfilaments, Intermediate filaments and Microtubules
What are microfilaments made of
Actin
What are microtubules made of
Two tubulin subunits; Alpha and Beta
What proteins attach to microtubules and serve as the ‘motorway network of cell’
Dynein and Kinesin; both are ATPase
Dynein moves toward cell centre
Kinesin moves away from cell centre
Location of synthesis of RNA in a cell
mRNA and tRNA - Transcribed in Nucleus
rRNA - Transcribed in Nucleolus
Differentiate Euchromatin and Heterochromatin
Euchromatin - Actively undergoing transcription, light grainy colour, unwound
Heterochromatin - Condensed, wound, not transcripting
Role of Smooth Endoplasmic Reticulum
Process proteins produced in RER
Synthesis of lipids
3 types of intercellular junctions
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
Common stain in preparing slides
Haematoxylin and Eosin - Stains acidic molecules like DNA purplish blue and stains basic molecules like plasma proteins pinkish red
4 basic tissue types
Epithelium, muscle, nervous and connective
Types of connective tissue
Soft - Tendons, ligaments, epidermids
Hard - Bone and cartilage
Blood and lymph - Specialized form
Types of soft connective tissue
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
Types of bone
Outer shell of dense cortical bone - Diaphysis
Cancellous or trabecular bone - Epiphyses
Types of cardiac muscle
Smooth, skeletal and cardiac
What ‘coat’ covers nervous tissue
Meninges in CNS
Epineurium in PNS
Types of neurons
Multipolar - Many dendrites, one axon
Bipolar - One dendrite, one axon
Pseudounipolar - Short processes, axon in both direction
Types of Glia
CNS - Astrocytes - Support, ion transport, induce blood brain barrier Oligodendrocytes - Produce myelin Microglia - Immune surveillance Schwaan Cells - Myelin in PNS
Major salivary glands
Parotid - More serous secreting cells
Submandibular - Equal number of cells
Sublingual - More mucus secreting cells
Function of striated ducts in salivary glands
The ducts pump salt out of the fluid so that it’s hypotonic to blood
4 parts of the digestive tract
From lumen out -
Mucosa - Epithelium, lamina propria, muscularis mucosae
Submucosa
Muscularis externa - Inner circular and outer longitudinal layer of smooth muscle
Serosa or Adventitia
What is the enteric nervous system?
The digestive tract has its own nervous system called Enteric nervous system
Basic structure of the liver
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.
What is the portal triad?
The hepatic portal vein + Hepatic artery + Bile duct
Endocrine vs exocrine glands
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)
