Practical 1: Cell and tissue damage, reactive changes, recovery reactions: Flashcards
To a certain degree, tissues can adapt to changing circumstances. Which reaction of adaptation is seen during a decrease of activity?
a. hyperplasia
b. hypertrophy
c. atrophy
d. metaplasia
c. atrophy
Name a process which is mainly based on hypertrophy
a. postmenstrual regeneration of the endometrium
b. muscle growth as seen in bodybuilders
c. growth of the uterus during pregnancy
d. wound healing
b. muscle growth as seen in bodybuilders
An increase in proliferation leading to an increase in the number of cells in a tissue is called
a. hypertrophy
b. hyperplasia
c. metaplasia
d. hypoplasia
b. hyperplasia
Myocardial hypertrophy of the left ventricle is propelled by…?
Mechanical and growth facotrs
A growing tumour causes pressure atrophy in surrounding tissues quite often. How is pressure atrophy caused? By:
a. a local effect of substances that are secreted by tumours
b. ischemia of surrounding tissues
c. tissue damage by an inflammation that targets tumour cells
d. denervation of surrounding tissues by pressure on nerves
b. ischemia of surrounding tissues
Protein degradation in living cells mainly occurs via:
a. activation of the mitochondrial phospholipase route
b. phagocytosis by adjacent macrophages
c. induction of trypsinization
d. proteasomal degradation or autophagy
d. proteasomal degradation or autophagy
Not every organ reacts to an increased activity with hypertrophy or hyperplasia. Think of an organ of which parenchymal cells hardly divide, in which increased activity does not lead to hypertrophy.
The central nervous system is an example of tissue where cell division remains absent even during increased activity. It is easy to imagine why: if deep contemplation would cause brain cells to divide or grow, the brain would become incarcerated in the limited space of a human skull. This would lead to brain stem compression in the foramen magnum, followed by ischemia of its vital structures.
Why doesn’t secrete leave the nipple in a resting mamma?
There is a dynamic balance between mammary fluid production and resorption. Acinar produce is resorbed in ducts and ductile, leaving the nipple surface dry. If secrete production increases, it will leave the nipple.
Could you give the correct terminology for the changes seen in this mammary gland, compared to a slide that shows a resting mammary gland?
The acini are hyperplastic (they are increased in number). Secondly, the acing epithelial cells are enlarged and hypertrophic as they produce and secrete milk actively.
Compare this slide to the slide of resting mammary tissue in the fertile state. What are the most important differences?
Lobuli in postmenopausal involuted mammary tissue are scarcely present. They are atrophic: this means that they are decreased in number, reducing the number of acini per lobules as well. The epithelial cells are also small and atrophic. The specialized, loose connective stroma of the lobules is replaced by a sturdy, collagen connective tissue. These stromal changes can lead to progressive acing obliteration, resulting in destruction of complete lobule. Acini can furthermore show stasis of secrete, forming small or large cysts. This can form a painful, palpable nodule in the breast which has to be evaluated to rule out breast cancer. The amount of interlobular fatty tissue has increased.
What causes the reduction of the amount of gland tissue?
a. an absolute loss of cells
b. the shrinking of gland cells.
Both! (an absolute loss of cells & the shrinking of gland cells)
Atrophy of the mammary gland is a consequence of net cell loss. There is more apoptosis than cell division. The atrophic cells are smaller due to proteasomal protein degradation and autophagy of cell components (which results in a reduction in cell size)
Inspect two mammograms, one of a 40y/o woman and the other of a 68y/o woman. What consequences could the increased concentration of fatty tissue have when evaluating a mammogram?
The right image (not that this info has any use, but maybe you can remember how it looked)
On the mammogram of a 68y/o woman, a suspected density is visible. After proving the existence of a breast carcinoma on that location with a fine-needle aspiration biopsy, the woman is operated in a breast-conserving manner. This means that the surgeon only removes the tumor with a surrounding rim of healthy mammary tissue, instead of the entire mammary gland (which used to be the standard operation)
Mammary gland tissue atrophy of the involuting postmenopausal mamma is an example of physiological atrophy. We will now study an example of pathologic atrophy, in a muscle biopsy of a 2y/o girl suffering from hypotonia. After childbirth, her parents had already noticed that she did not move as much as other children. Which two organ systems can harbor the cause for hypotonia? The:
a. endocrine system
b. gasto-intestinal system
c. muscular system
d. urogenital tract
e. nervous system
The muscular and nervous system.
The cause may lie in the nervous system (neurogenic muscular atrophy) or muscles themselves (myogenic muscular atrophy). Each of these two groups consists of a large number of different diseases, but that is specialized neurology (for more info see Chapter 27)
Musle fibers may be enlarged (hypertrophic) or smaller than normal (atrophic). In this case, a mixture of smaller and larger muscle fibers is visible. Explain.
Dysfunctional nerves can cause neurogenic muscular fibre atrophy in those fibres that are innervated by said nerves. Other muscle fibers which remain innervated become hypertrophic to compensate for the loss of muscle. It is impossible for muscle fibers to compensate hyperplasia, because muscle cells hardly divide
The definition of metaplasia is:
a. A reduction in differentiation, resulting in the presence of undifferentiated cells.
b. Excessive formation of differentiated tissue
c. Replacement of differentiated cells by cells of another differentiation type
d. Metastasis of an anapestic tumour
c. Replacement of differentiated cells by cells of another differentiation type
