IMMS Flashcards
What colour do nerve cells stain?
Shades of brown
What cells are in the spinal cord?
Within the spinal cord are some motor neurons. These are some of the largest cells in the body (see image below).
What do motor neurones show?
Motor neurons in the ventral horn of the spinal cord showing axons or dendrites arising from them. These are described as multipolar cells because when seen whole they have more than two processes.
What are lymphocytes like?
- among the smallest nucleated cells in the body
- circulate in the blood and are found in large numbers in organs such as in lymph nodes, the tonsils and the thymus gland
- Many tissues also have lymph nodules full of lymphocytes within their fabric.
What can the lymph node be stained with?
Part of a lymph node stained with H&E showing many small lymphocytes.
What does the nucleus of lymph nodes stain?
The nuclei of these cells stain dark blue but their cytoplasm is very scanty
Which dyes are used to stain?
two dyes, haematoxylin and eosin. This is often referred to as H&E staining.
What colour does H&E stain?
Haematoxylin stains cell nuclei blue and eosin stains cell cytoplasm and many extracellular fibres pink.
What does the dark blue stain of a cell nucleus show?
The cell nucleus that stains dark blue with haematoxylin can tell you a lot about the metabolic activity of a cell.
What does the size of the cell nucleus show?
A large cell nucleus often denotes a highly active cell whereas a thin or small nucleus in which it is difficult to see any of the infrastructure often denotes a relatively dormant cell.
What is thyroid histological image like?
Image shows:
• roughly circular structures (in 2D – spheres in 3D)
•Each lined by a single layer of cuboidal/columnar epithelial cells
•Centre of each structure is acellular, filled with a homogenous eosinophilic material
What are tissue slices size?
Thinner than a cell
What is the most common dye?
Haematoxylin and Eosin (H&E).
Many extra cellular fibres e.g. collagen,elastic stain pink
What does not stain?
Watery extra-cellular jelly does not stain at all
What are the other stain?
PAS - sugars
Van Gieson - elastic
Trichromatic - 3 types of cell
Alcian blue - mucins
What are the size of lymphocytes?
Small cells – lymphocytes about 10 micrometres in diameter, with very little cytoplasm
What are the size of motor neurones?
Large cells – motor neurons 100 micrometres wide with axons up to 1 meter in length
What are the shapes of cells?
Rounded
Polygonal
Fusiform
Squamous (flattened)
Cuboidal
Columnar
How does metabolic activity relate to size of cell?
Inactive/dormant cells are smaller
Metabolically active cells often have nucleoli
What cells last days, months, years?
Days: lining of the gut
Months: lots of tissues –
blood
skin
connective tissues
Years: bone and tendons
Nearly whole life: (limited regeneration) skeletal muscle
Whole life: nerves and brain
cardiac (heart) muscle
germ cells
What does the nucleus contain?
Euchromatin
Heterochromatin
Nucleolus
Double nuclear membrane
DNA
What occurs at the nucleolus?
1-3 microns in diameter
Site of ribosomal RNA formation
What is the mitochondria like?
Powerhouses of the cell
Site of oxidative phosphorylation
Have their own DNA
Double membrane – inner membrane is
What occurs at the outer and inner membrane of the mitochondria?
Outer:Lipid synthesis
FA metabolism
Inner: Respiratory chain
ATP production