Histology Flashcards
What colour does Haematoxylin and Eosin stain cell nuclei and cytoplasm?
Cell nuclei- blue
Cytoplasm- pink
Collagen and elastin - also pink
Where are cytokeratins found
Epithelial cells
Where is desmin found
Myocytes
Where are glial fibrillary acidic proteins found
Astrocytic glial cells
Where are neurofilament proteins found
Neurons
Where is nuclear laminin found
Nuclei of all cells
Where is vimentin found?
Mesodermal cells
What does simple squamous epithelium line?
Characteristic of their nuclei
Endothelium (inside of blood vessels), mesothelium (outside of the lungs, alveoli) and peritoneum (abdominal organs)
Parallel oval nuclei
What does simple cuboidal epithelium line?
Characteristic of their nuclei
Kidney tubules, small ducts (salivary gland)
Central spherical nuclei
What does simple columnar epithelium line?
What is an additional characteristic?
Lines the stomach, intestines and uterus
May or may not have microvilli (small intestine) or cilia (respiratory tract, reproductive tract)
Where would you find stratified squamous non-keratinising epithelium?
- In wet sites of the body that experiences lots of abrasion
- Oesophagus, vagina, mouth
Where would you find stratified squamous keratinising epithelium?
- The skin (e.g. when you take a shower, you do not absorb the water through your skin) - also when in a dry environment, water does not pass out of the skin in an uncontrolled manner
Thinner ones- skin on eyelids
Thicker layer of keratin- palms of hand and soles of feet
What are basement membranes made of? What stain should you use to identify it?
Type 4 collagen and fibronectin
Periodic acid schiff is used for basement membrane identification
What do mesenchymal cells give rise to?
- Fibroblasts
- Chrondroblasts
- Obsteoblasts
- Adipocytes (white and brown)
What are two origins of connective tissue cells?
- Mesenchymal cells and haematopoetic stem cells
What do haematopoetic stem cells give rise to?
- Monocytes
- Macrophages
- Lymphocytes
- Mast cells
- Blood cells
What are the 3 visible fibres of connective tissue?
Collagen, elastin, reticulin
What do fibroblasts secrete?
Tropocollagen, elastin
Type 1 collagen
Skin, bone and tendons
Type 2 collagen
Cartilage
Type 3 collagen
(aka reticulin)- liver, kidneys, bone marrow and spleen
Type 4 collagen
Basement membrane
Type 5 collagen
Placenta
Is cartilage avascular or vascular?
Avascular - derives blood supply from either side of the cartilage
Describe the synovium. What are 2 types of cells present? Vasculature and innervation?
- lines the insides of the joint capsule
- Comprise 1-4 layers of synovial cells
- Has Type A cells- phagocytes and type B cells - rich in rER - produces synovial fluid
- Richly vascular and are highly innervated
What are the characteristics of smooth muscle?
Fusiform cells with a central (oval/flattened) nucleus.
Have no striations
Non branching
What epithelium are true and false vocal cords lined by?
False vocal cords- respiratory epithelium
True vocal cords- non keratinised stratified squamous epithelium
What epithelium does the gallbladder have?
Simple columnar with a poorly developed brush border
What does the posterior pituitary store and secrete?
What is the posterior pituitary?
Oxytocin and vasopressin (ADH)
(Composed of axons and glial cells)- is a downward extension of the hypothalamus
Are endothelial cells richly vascularised?
Yes
What are the pituicytes present in the anterior pituitary and in what proportion?
Somatotrophs- 50%
Lactotrophs- 25%
Corticotrophs- 15-20%
Gonadotrophs- 10%
Thyrotrophs- 1%
What do the pituicytes of the anterior pituitary gland secrete?
Somatotrophs- Growth hormone
Lactotrophs- Prolactin
Corticotrophs- ACTH (glucocorticoids and androgens)
Gonadotrophs- FSH and LH
Thyrotrophs- TSH
How would you recognise lactotrophs on an immunohistochemical stain?
They are polygonal cells that have cytoplasmic processes wrapping around other cells
How how would you recognise thyrotrophs on an immunohistochemical stain?
They are more angular chromophobes with elongated cytoplasmic processes (that does not wrap around other cells like lactotrophs)
What shape are gonadotrophs?
round/oval cells
What are the supporting cells of the anterior pituitary?
Sustentacular cells
(stained with S100)
What cells are present in the pineal gland and what do they secrete?
What is brain sand?
Pinealocytes arranged in rosettes
- They secrete melatonin
Brain sand- calcium accumulating with increasing age (marker of midline in x rays)
What hormones does the thyroid gland secrete?
Thyroxine and calcitonin
Which cells secrete parathyroid hormone?
Chief cells of the parathyroid gland
Where are the islets of langerhans most populous?
In the pancreatic tail
What are the 4 cells of the endocrine pancreas. What proportion are they in?
Beta cells - insulin -70%
Alpha cells- glucagon - 20%
Delta cells- somatostatin 5-10%
PP cells- pancreatic polypeptide 1-2%
What are the 3 layers of the adrenal cortex and what do they secrete?
Describe each layer briefly
Zona glomerulosa- mineralocorticoids (Aldosterone) – Thin, incomplete layer
Zona fasciculata- glucocorticoids (Cortisol) – most prominent layer with large polygonal cells and almost clear cytoplasm
Zona reticularis- Androgenic steroids (columns of small polygonal cells)
What does the adrenal medulla produce and what is its histological description?
It comprises large, polyhedral chromaffin cells and secretes adrenaline and noradrenaline
Alcian blue stain
Stains
- Mucous goblet cells
- Mast cell granules
- Cartilage matrix
(GAG rich structures)
Blue
Haematoxylin and eosin stain
Proteins- pink
Keratin- orange/red
Nuclei and RNA - blue
Iron haematoxylin
Nuclei and elastic fibres - black
Periodic acid schiff
Hexose sugars and complex carbohydrate containing structures (goblet cells, mucins, cartilage, glycogen, basement membrane) - Magenta
Perl’s stain
Ferric iron - stained prussian blue
Romanovsky stains - Leishman’s stains
Neutrophils, lymphocyte, monocyte, basophils - dark blue/purple
Eosinophil- pale blue
Erythrocytes - red
Toludine blue
Nuclei, ribosomes, cytoplasm - dark blue
GAG rich components- bright purple
Van gieson’s trichrome
Collagen- pink/red
Cytoplasm- yellow/olive green
Nuclei- black
