D.
Celullar Adaption (Flick 2)
1. Pg. 10 fig. 2.3. Change in growth of cells
Describe three normal physiological adaptive reponses to pathological
(disease)
The tree normal physiological adaptive response :
a) Increased cellular activity
b) Decreased cellular activity
c) Alteration of cell morphology
2. Pg.13 fig. 2.4. adaptive responses resulting in increased tissue mass
What is definition of hyperplasia and hypertrophy ?
a. Hyperplasia is an increase in the number of cells in a tissue caused by
increased cell divition. As this type change can occur only in tissues that
have the capacity for cell divition, hyperplasia is not an adaptive reponse
seen in skeletal muscule, cardiac muscule or nerve cells, which are non-
dividing cell populations. Hormonal influences are important in this
growth response.
b. Hypertrophy in the absence of hyperplasia is typically seen in muscle
where the stimulus is an increased demand for work. Taken at the same
magnification, (a) shows muscle fibres in transverse section from the
soleus muscle of a normal 50-years-old male and (b) shows fibres from
the same muscle in a verteran marathon runner. Note the dramatic
increase in the size of the fibres in response to the demands of marathon
running.
Mention the stimulus that usually causes hypertrophy and hyperplasia.
Increased functional demand or endocrine stimulation the stimulus that usually
causes hypertrophy and hyperplasia. These new patterns of growth are stable
while the causative returns to normal pattern of growth.
3. Pg 13 fig. 2.5. Hypertrophy of skeletal muscle cells
Describe based on fig 2.5. a and b the hypertrophy cells
a. Hypertrophy in the absence of hyperplasia is typically seen in muscle
where the stimulus is an increased deman for work. Taken at the same
magnification, (a) shows muscle fibres in transverse section from the
soleus muscle of a normal 50-years-old male and (b) shows fibres from the
same muscle in a verteran marathon runner. Note the dramatic increase in
the size of the fibres in response to the demands of marathon running.
b. Increased cell mass a tissue can result from physiological stimuli. An
increase in functional cell mass trough hypertrophy or hyperplasia may be
physiological.
The thyroid gland enlarges in pregnancy, owing to the stimulus of
pregnancy- associated high levels of TSH on thyroid epithelial cells
(hyperplasia).
In athletes, skeletal muscle fibres increase in size (hypertrophy) in
responses to exercise and increased metabolic demands.
4. Hyperplasic and hypertrophy of myometrium in pregnancy
Differentiate between normal uteri with uterus from recently pregnant woman
based on picture.
On the left is a normal uterus showing the normal mass of smooth muscle in its wall. On
the right is uterus from a recently pregnant woman, in which the striking increase in mass
of smooth muscle is evident. At a cellular level this is due to both hyperplasia and
hypertrophy of uterine smoth muscle.
5. Pg. 17 fig 2.12. Apoptosis
Describe the process of Apoptosis.
Apoptosis of cells is a programmed and energy-dependent process designed specifically
to swich cells off and eliminate them. This controlled pattern of cell death termed
programmed cell death, is very different from that which occurs as a direct result of a
serve, damaging stimulus to cells (discussed in chapter 3).
6. Pg 27 fig 3.5 Relationship between sub lethal and lethal cell demage
a. Describe how is damage cell can recovery by own self.
The cell can recover following removal of the damaging stimulus. Damaged proteins
and organelles are removed by a cell stress response and autophagy with new
structural components being synthesized.
b. Describes how is damage cell cannot recovery and progress to cell death
In other situations a damaging stimulus may first causes sublethal damage and then,
because the cell cannot trecover, progress to cell death. After cell death a set of
structural changes termed necrosis takes place. If the damaging stimulus to a cell is
massive, the cell is killed immediately without passing trough the stages of necrosis.
This occours most commonly with overwhelming physical agents such as severe heat
or strong acids, both of which coagulate cell proteins.
7. Pg 28 fig 3.6 Sub Lethal cell damage
a. Differentiate between normal and injured liver cells on hydrophic degeneration
of liver
The normal cell cytoplasm is pink with a faint hint of purple, the purple coloration
(basophilia) being due ribosome, mainly on the RER. normal liver cells contrast with
injured cells, which are swollen, pale and vacuolated.
b. Describe the fatty change of the liver from an alcoholic patient
Fatty changes with large vacuoles of fat within hepatocytes. As solvents used in
conventional histologic preparation dissoleve out the fat to leave a clear spce, lipid can
be positively demonstrated only by using frozen sections.
8. Pg 29 fig 3.8 celluar events in necrosis
Differen and then decribe with your own word about normal
cell,pyokinesis,karyorrhexin, adn karyolysis :
a. Normal cell with haematoxylin and eosin staining the normal cell has an
open nucleus often with a visible nucleolus. The cytoplasm has a pale pink
colour with a hint of purple form cellular RNA, mostly in rough endoplsmic
reticulum. If there has been sublethal in damage cyroplasmic vacuolation may
be seen.
b. Pyknosis the early necrotic cell shows shrinkage increased
cytoplasmiceosinophilia (pink staining) . There is a loss of cytoplasmic RNA
resulting in lack of any purple tint to the cytoplasm . The nucleus becomes
small and intensely basophilic, termed pyknosis, wich indicates cessation of
DNA transcription.
c. Karyormexis is the process of necrosis continues with nucleases causing
fragmentation of the nucleus into several small pieces in a prosess termed
karyorrhexis. The cell remains small and eosinophilic and may start show
irregularities in countur reslecting cell membrane breakdown.
d. Karyolysis is Necrosis continues with complite dissolution of the nucleus
termed karyolysis and leavers the necrotic cell as a mas of parly denatured
protein still heaving the same rough outline as the normal cell. The cytoplasm
is deeply eosinophilic and contrasts markedly with the normal cell shown in
fig. 3.8a
9. Pg 30 fig 3.9 several different patters of necrosis.
Indentify the varying macroscopic appearances of the necrotic tissue and
describe form the picture.
a. Coagulative necrosis describes dead tisue that appears firm and pale, as if
cooked. In areas of coagulative necrosis, much of the cellular outline and tissue
architescture canstill be discerned histologically, even though the cells are
dead, the most common cause of this pattern of necrosis is occlusion of the
aterial supply to a tissue . protein liberated form dead cells can the blood
b. Liquefactive or colliquative necrosis describes dead tissue that appeas semi-
liquid as aresult of disssolution of tissue by the action of hydroytic enzymes.
The most common types of damage leading to the liquefactive pattern are
necrosis in the brain owing to aeterial occlusion(cerebral infraction and
necrosis caused by bacterial infections)
c. Coseous necrosis describes dead tissue that is soft and white, resembling cream
cheese. With this type of necrosis, dead cells form an amorphous proteinaceous
mass but, in contrast to coaglutive necrosis, no priginal architescture can be
seen histologically. This pattern is invarialby associated with tuberculosis.
d. Gummatous necrosis describes dead tissue when it is firm and rubbery. As in
caseeous necrosis the dead cells form an amorphous proteinaceous
histologically. However,the gummamtous pattern is restricted to describing
necrosis in the spirochaetal infection syphilis
e. Haemorrhagic necrosis describes dead tissuers that are suffused with
extravasated red cels. This pattern is seen particularly when cell death is due to
blockage of the venous drainage of a tissue, leading to massive congestion by
blood and to subsequent arterial failure of perfusion
f. Fat necrosisis decribes foci of hard yellow material seen in dead adipose tissue
this reaction can occur after liberation of pancreatic enzymes into the peritonal
cavity, following in flammation of the pancreas. It may also be seen after
trauma to fat for example in the breast.
g. Fibrinoid necrosis is a term used to decribe the histological appearance of
arteries casses of vasculitis and hypertension, when fibrin is deposited in the
damage necrotic vessel wall
