MLT GlobeHistopathology: Cells, tissues & basic histology – page 2
88 Histopathology MCQs on Cells, tissues & basic histology with answers and explanations.
Nissl substance (clumps of rough ER) is characteristic of which cells?
Nissl bodies are basophilic rough ER in neuronal cell bodies, reflecting intense protein synthesis.
Which glial cell forms myelin in the peripheral nervous system?
Schwann cells myelinate peripheral axons; oligodendrocytes myelinate CNS axons.
The upper oesophagus is lined by which epithelium?
Multiple squamous layers resist abrasion by swallowed food; columnar epithelium begins at the gastric junction.
Most of the fetal skeleton is first formed as a model made of:
Long bones develop by endochondral ossification that replaces a hyaline cartilage model.
Which structure forms part of the cell's cytoskeleton?
The cytoskeleton comprises microfilaments, intermediate filaments and microtubules; ribosomes and nucleoli handle protein and rRNA synthesis.
In the kidney, the glomerulus is:
The glomerulus is the filtering capillary tuft between afferent and efferent arterioles.
Retinal neurons that link photoreceptors to ganglion cells have one dendrite and one axon. They are:
Bipolar neurons have two processes and occur in the retina, olfactory epithelium and inner ear ganglia.
Grey matter of the central nervous system consists mainly of:
Grey matter holds neuron cell bodies, dendrites and synapses; white matter is pale because of myelinated axons.
A tendon, with parallel collagen bundles resisting pull in one direction, is made of:
Parallel collagen fibres resist tension along one axis; dense irregular tissue (dermis) has fibres in many directions.
Which class of neurons is the most numerous in the nervous system?
Interneurons, which link sensory and motor pathways within the CNS, make up the vast majority of neurons.
Which tissue covers the exposed crown of a tooth?
Enamel covers the crown and is the hardest body tissue; cementum covers the root and dentin forms the bulk.
A neutrophil engulfs a bacterium. This uptake of particulate matter is called:
Phagocytosis is 'cell eating' of particles; pinocytosis takes in fluid, and exocytosis releases material.
Which muscle type has intercalated discs linking its cells?
Intercalated discs contain gap junctions and desmosomes that let cardiac cells contract in synchrony.
Mesothelium forms the surface lining of which layer of the gut wall?
Mesothelium is simple squamous epithelium lining serous membranes such as peritoneum, pleura and pericardium.
Which meningeal layer is closely attached to the surface of the brain?
The thin pia mater follows every gyrus and sulcus; the arachnoid bridges over them and the dura is outermost.
Absorptive cells of the small intestine show a striated or brush border on light microscopy. What structures produce it?
The brush border consists of thousands of short, actin-cored microvilli that increase surface area. Cilia are longer and motile; stereocilia are long microvilli found in the epididymis and inner ear.
Pain and temperature in the skin are detected mainly by receptors that lack a connective tissue capsule. These are:
Free nerve endings are unencapsulated terminals mediating pain and temperature. Pacinian and Meissner's corpuscles are encapsulated, and Ruffini endings have a thin capsule.
A cell actively secreting enzymes has abundant cytoplasmic basophilia. Which organelle actually assembles the polypeptide chains?
Ribosomes, free or attached to rough ER, translate mRNA into protein; their RNA causes cytoplasmic basophilia. Peroxisomes handle oxidative reactions and centrioles organize microtubules.
The thin cellular layer lining the inner bone surface facing the marrow cavity is the:
Endosteum lines the medullary cavity and trabeculae and contains osteoprogenitor cells. Periosteum covers the outer surface; perichondrium surrounds cartilage; perimysium wraps muscle fascicles.
In longitudinal section, which muscle type shows many nuclei pushed to the periphery of each fiber, just under the sarcolemma?
Skeletal muscle fibers are multinucleated syncytia with peripheral nuclei. Cardiac and smooth muscle cells each have one (occasionally two) centrally located nuclei.