IMMS - Histology Flashcards
Describe the location and function of simple squamous epithelia
- Alveoli
- Lining of heart
- Blood and lymphatic vessels
- Allow materials to pass through by diffusion/filtration
- Secrete lubricating substances
Describe the location and function of simple cuboidal epithelia
- Salivary glands
- Duct of kidney
- Secretion and absorption
Describe the location and function of simple columnar epithelia
- Ciliated: bronchi, fallopian tubes, uterus
- Non-ciliated: digestive tract and bladder
- Absorption. Goblet cells also secrete mucus
Describe the location and function of pseudo-stratified columnar epithelia
- Trachea
- Secrete mucus with ciliated tissue moving it
Describe the location and function of stratified squamous epithelia
- Keratonising: skin
- Non-kertanising: mouth, vagina
- Protects against abrasion
What does alcian blue stain and what colour does it go?
- Polysaccharides
- GAGs
- Cartilage
- Stains blue/purple
What does eosin stain and what colour does it go?
- RBC
- Proteins in cytoplasm
- Stains a purple
What does haematoxylin stain and what colour does it go?
- Nuclei
- RNA
- Stains dark blue
What does PAS stain and what colour does it go?
- Polysaccharides
- Glycoproteins
- Glycolipids
- Stains beige/purple
What is the stain H&E made up of?
- Heamatoxylin and eosin
How many types of collagen are there?
12
What do collagen 1 - 5 form?
1 - Skin, bones, teeth 2 - Cartilage 3 - Liver, kidney, spleen 4 - Basement membranes 5 - Placenta
What is collagen secreted by?
Fibroblasts
What is unique about the collagen reticulin?
Can form branches
Name the 2 types of connective tissue
Loose and dense
What are elastic fibres made up of?
Fibrilin in an elastin matrix
What colour do elastic fibres stain with H&E and what enables them to be distinguished from collagen?
- Stain pink
- Elastin stains stronger and has a glassy appearance
What is elastin produced by?
Fibroblasts
Name the two types of adipose tissue and the differences
- White: Single fat droplet in large cell
- Brown: Multiple fat droplets
Name the 3 types of muscle
- Smooth
- Skeletal
- Caridac
Describe smooth muscle
Discrete cells, functioning as a whole.
Contractile proteins anchored in clumps to inside of cell membrane
Secrete a reticulin rich lamina (basement membrane)
Joined by gap junctions
What is the appearance of longitudinally cut and transversely cut smooth muscle?
- Longitudinal: Fusiform cells with central nuclei
- Transverse: Round cells with central round nuclei
What is the structure of gap junctions?
6 connexons proteins
What does skeletal muscle look like cut longitudinally and transversely?
- Longitudinal: long, unbranched fibres with nuclei at edge of membrane
- Transverse: Fasiculi with white spaces between each one. Again, nuclei at edge of membrane
What are fasiculi?
Groups of muscle fibres surrounded by conenctive tissue
What is the perimysium?
The connective tissue around fasiculi
What is the endomysium?
Connective tissue between muscle fibres
What is the epimysium?
Connective tissue around bundles of fasiculi which create muscle
Describe cardiac muscle
Branched, rectnagular cells with central nuclei.
Connected via intercalated discs
Which cells secrete cartilage?
Chondroblasts
What do chondroblasts become?
Chondrocytes trapped in the matrix
Describe the structure of cartilage
Cells embedded in GAG. Cartilage is surrounded by collagenous perichondrium
Describe hyaline cartilage
GAG with small chondrocytes
Describe elastic cartilage
GAG with small chondrocytes
More elastin, darker pink stained strands
Describe fibrocartilage
GAG with small chondrocytes
Lots of branched-looking collagen fibres
Describe the histological appearance of mineralised bone
Circular osteons with golden/brown Haversion canals at centre
Describe the histological appearance of decalcified bone
Stains pink with H&E, mainly just concentric circles of collagen remaining
Describe the location and histological appearance of membrane bone
In skull. Thin plates with large, purple-stained osteoblasts on either surface
