MLT GlobeHistopathology: Cells, tissues & basic histology
88 Histopathology MCQs on Cells, tissues & basic histology with answers and explanations.
Apart from the nucleus, which organelle carries its own circular DNA?
Mitochondria have their own circular genome, reflecting bacterial ancestry; the other organelles lack DNA.
Which item is a cytoplasmic inclusion rather than an organelle?
Inclusions are stored or non-living materials such as glycogen and lipid droplets; ribosomes, mitochondria and Golgi are organelles.
Adrenal cortical cells produce large amounts of steroid hormones. Which organelle is prominent in them?
Smooth ER holds the enzymes of lipid and steroid synthesis; rough ER is prominent in protein-secreting cells.
Which organelle contains catalase and protects the cell by breaking down hydrogen peroxide?
Peroxisomes carry out oxidative reactions and use catalase to destroy the H2O2 they produce, limiting oxidative damage.
The mucosa of the fallopian tube is lined by:
The tubal lining is a single columnar layer mixing ciliated cells, which move the ovum, and secretory peg cells.
Which connective tissue cell secretes antibodies and so mediates humoral immunity?
Plasma cells are terminally differentiated B cells that secrete immunoglobulin; T cells mediate cell-mediated immunity.
Rapid gas exchange across alveolar walls is made possible by a lining of:
Type I pneumocytes are thin, flat cells giving a short diffusion distance; thicker epithelia would slow gas exchange.
In allergic reactions, IgE binds to surface receptors on which cell, which then releases histamine?
Mast cells carry high-affinity IgE receptors; cross-linking by allergen triggers degranulation with histamine release.
The matrix of which tissue is made mainly of type II collagen?
Type II collagen is characteristic of hyaline and elastic cartilage; bone, dermis and tendon are rich in type I.
Hyaline cartilage covering the ends of long bones mainly serves to:
Articular hyaline cartilage lets bones glide and absorbs load; blood transports, adipose stores fat and marrow makes blood cells.
Sertoli cells, which support developing sperm, are found in the:
Sertoli cells line the seminiferous tubules and nourish germ cells; the liver's resident macrophages are Kupffer cells.
Which is the main function of blood as a connective tissue?
Blood carries substances through plasma and cells; fat storage is adipose tissue's role and contraction is muscle's.
Smooth muscle in the gut wall mainly functions to:
Involuntary smooth muscle contracts in waves to propel gut contents; cardiac muscle pumps blood.
Which junction lets ions and small molecules pass directly between adjacent epithelial cells?
Gap junctions have connexon channels linking cytoplasms; tight junctions seal, desmosomes anchor cells, hemidesmosomes attach to basement membrane.
The body is built from four basic tissue types. Which list is correct?
Bone and blood are specialised connective tissues, and skin is an organ, so they are not separate basic tissues.
A single layer of thin, flattened cells describes which epithelium?
Simple squamous epithelium lines alveoli, vessels and body cavities; cuboidal and columnar cells are taller.
Kidney tubules, thyroid follicles and small gland ducts are lined by cells as tall as they are wide. This epithelium is:
A single layer of cube-shaped cells suits secretion and absorption in these sites; stratified cuboidal is confined to larger ducts.
The lining of the trachea and bronchi, where cilia sweep mucus upwards, is:
Respiratory epithelium looks layered but all cells touch the basement membrane; goblet cells make mucus and cilia move it.
Which basic tissue covers body surfaces, lines cavities and passages, and forms glands?
Epithelium forms coverings and linings and gives rise to glands; skin is an organ containing several tissues.
Which structure is made mainly of nervous tissue rather than connective tissue?
The spinal cord is CNS tissue; the symphysis (fibrocartilage), ligaments and areolar tissue are connective tissues.