Pathoma - Growth Adaptations, Cellular Injury, Cell Death - Fundamentals Of Pathology

Front 1

What are the two basic principles of growth adaptation of organs?

Back 1

(A) An organ is in homeostasis with the physiologic stress placed oil it.

(B) An increase, decrease, or change in stress on an organ can result in growth adaptations.

Front 2

An increase in ______ leads to an _______ in organ size.

Back 2

stress; increase

Front 3

An increase in organ size of an organ occurs by _____ and/or ____.

Back 3

hypertrophy; hyperplasia

Front 4

What does hypertrophy involve?

Back 4

(1) Gene activation
(2) Protein synthesis
• Cytoskeleton gives a cell its size/shape.
• ↑ (1) & (2) gives a larger cytoskeleton

(3) Production of organelles

Front 5

What does hyperplasia involve?

Back 5

Hyperplasia involves the production of new cells from stem cells.

Front 6

Generally, the two mechanisms underlying increased organ size occur ________ (together/separately). An example would be _______.

Back 6

Together; uterus during pregnancy (SMC does both)

Front 7

__________ tissues cannot make new cells. They undergo ________ only.

Back 7

Permanent; hypertrophy

Front 8

What are examples of permanent tissues?

Back 8

• Cardiac muscle
• Skeletal muscle (not entirely true; myosatellite cells)
• Nerve (but not in the hippocampus)

Front 9

Give an example where a permanent tissue undergoes its growth adaptation to stress.

Back 9

Cardiac myocytes hypertrophy in response to systemic HTN.

Front 10

This mechanism of growth is pathologic and can progress, what does this mean?

Back 10

Pathologic hyperplasia (e.g., endometrial hyperplasia) can progress to dysplasia and, eventually, cancer.

Front 11

Pathologic hyperplasia is when hyperplasia occurs due to what?

Back 11

An underlying pathologic process.

Front 12

This is an exception to the rule that pathologic hyperplasia can give rise to dysplasia.

Back 12

Benign prostatic hyperplasia (BPH) does not
increase the risk for prostate cancer, even though it is a pathologic hyperplasia.

Front 13

What is atrophy?

Back 13

A mechanism of growth adaptation. Decrease in stress (e.g., decreased hormonal stimulation, disuse, or decreased nutrients/blood supply) leads to a decrease in organ size (atrophy).

Front 14

Atrophy occurs via ________.

Back 14

a decrease in the size and number of cells.

Front 15

Explain the mechanisms underlying atrophy.

Back 15

• Decrease in the number of cells occurs via apoptosis.
• Decrease in cell size occurs via ubiquitin-proteasome degradation of the cytoskeleton and autophagy of cellular components. In ubiquitin-proleosome degradation, intermediate filaments of the cytoskeleton are "tagged" with ubiquitin and destroyed by proteosomes. Autophagy of cellular components involves generation of autophagic vacuoles. These vacuoles fuse with lysosomes whose hydrolytic enzymes breakdown cellular components.

Front 16

A change in stress on an organ/tissue leads to a change in ________.

Back 16

cell type

Front 17

Metaplasia most commonly involves what type of cell?

Back 17

Surface epithelium

Front 18

Metaplastic cells are _________ (more/less) able to handle new stress.

Back 18

more

Front 19

Generally speaking there are three types of epithelium in the human body.

Back 19

• Squamous epithelium (keratinizing/nonkeratinizing)
• Columnar epithelium
• Transitional/Urothelium

Front 20

Give a classic example of metaplasia.

Back 20

Barret esophagus. Long standing GERD transforms the original nonkeratinizing squamous cells to a mucinous type of columnar epithelium (non-ciliated). Goblet cells are often present.

Front 21

How does metaplasia occur?

Back 21

By re-programming of stem cells, which then produce the new cell type.

Front 22

Metaplasia is ___________ (reversible/irreversible). Provide an example.

Back 22

reversible.

Treatment of GERD

Front 23

Under persistent stress, _________ can progress to _________and eventually result in __________.

Back 23

metaplasia; dysplasia; cancer

Front 24

Provide an example of metaplasia progressing to cancer.

Back 24

Barrett esophagus may progress to adenocarcinoma of the esophagus.

Front 25

What is this?

Back 25

We observe squamous epithelium transforming to a columnar non-ciliated epithelium. This is Barrett esophagus.

Front 26

This is an exception to the rule that metaplasia can progress to dysplasia and cancer.

Back 26

Apocrine metaplasia

It carries no risk of cancer.

Front 27

This vitamin deficiency can result in metaplasia.

Back 27

Vitamin A deficiency.

Front 28

Vitamin A is also needed for proper __________ of the cells of the _____________. How is this important?

Back 28

maturation; immune system

Patients with a t(15;17) in acute promyelocytic leukemia (M3). This translocation involves the vitamin A receptor. Cells become trapped in the blast state. One treatment of this is all-trans retinoic acid.

Front 29

Provide an example of vitamin deficiency-induced metaplasia.

Back 29

Keratomalacia of the eye. Vitamin A is needed to maintain specialized epithelia. E.g. the conjunctiva of the eye (stratified columnar). The metaplasia thickens the surface, resulting in keratomalacia.

Front 30

This is the most common primary source of conjunctivitis and pneumonia in newborns.

Back 30

Cervicitis. Caused by C. trachomatis, N. gonorrheae (these two are >50% of cases), Trichomonas vaginalis, Candida, HSV-2, HPV. In acute cervisitis, vaginal discharge is the most common complaint.

Front 31

Mesenchymal tissues are what?

Back 31

It include tissues like bone, blood vessel, fat, cartilage. Also known as connective tissues.

Front 32

This type of tissue can also undergo metaplasia. Provide an example.

Back 32

Mesenchymal tissue.

Myositis ossificans. Inflammation of the skeletal muscle results in a metaplastic production of bone within the skeletal muscle. Inflammation is usually due to trauma.

Front 33

A woman in her 40's had received a traumatic blow to his left arm. An X-ray showed the following:

What is this and what makes you exclude other diagnoses?

Back 33

Myositis ossificans.

It's probably not osteosarcoma (osteogenic sarcoma) because:

• Her age. ~75% occur in younger than age 20. Second peak occur in the elderly.
• Gender.
• Unusual location (60% occur around the knee; 15% around the hip; 10% around the shoulder)
• Margins are distinct (it is indistinct and infiltrating in osteosarcoma)
• In osteosarcoma the tumor would break through and lift the periosteum with reactive bone formation.

Front 34

Give two causes of vitamin A deficiency.

Back 34

(1) Diets lacking sufficient yellow and green vegetables
(2) Fat malabsorption (e.g., celiac disease)

Front 35

A ship carpenter stranded in the arctic had to rely on polar bear liver to survive. What would likely happen to this man and what would he experience?

Back 35

Vitamin A toxicity

Acutely, symptoms would mimic a brain tumor (!) such as headache, dizziness, vomiting, stupor, blurred vision. Over time he would lose weight, lose his appetite and get bone and joint pain (retinoic acid stimulates osteoclasts).

Front 36

Osteosarcoma: A triangular shadow on X-ray between the cortex and raised periosteum is called ________.

Back 36

Codman's triangle.

Front 37

Osteosarcoma: In particular, _____ gene mutations occur in 60-70% of sporadic tumors. Individuals with hereditary retinoblastomas (germ-line mutations in RB) have a ____________ increased risk of __________.

Back 37

RB; thousandfold greater risk; osteosarcoma

Front 38

Osteosarcomas typically present as ___________, although a ________ can be the first symptom.

Back 38

painful enlarging masses; pathologic fracture

Front 39

Osteosarcoma: At the time of diagnosis, approximately 10% to 20% of patients have demonstrable ____________ metastases.

Back 39

pulmonary

Front 40

Dys- means
plasia means

Back 40

Dys- means bad
plasia means growth

Front 41

What is dysplasia? What does it refer to? Provide an example.

Back 41

Disordered cellular growth. Term used to refer to proliferation of pre-cancerous cells. An example is CIN.

Front 42

CIN usually arises from longstanding ____________ or __________.

Back 42

pathologic hyperplasia; metaplasia.

Front 43

Dysplasia is _________ (reversible/irreversible) with alleviation of the inciting stress.

Back 43

Reversible

Front 44

Carcinoma is ________ (reversible/irreversible).

Back 44

Irreversible

Front 45

Aplasia _______ (is/is not) a growth adaptation.

Back 45

is not

Front 46

What is aplasia? Provide an example.

Back 46

Failure of cell production or organ growth during embryogenesis. Classic example is unilateral renal agenesis.

Front 47

What would be seen in unilateral renal agenesis?

Back 47

Decreased production of fetal urine leading to oligohydramnios. This restricts fetal movement in the uterine cavity. As a result, newborns have flat facial features (Potter's facies), underdevelopment ofthe chest wall, and clubfeet.

Front 48

Congenital anomalies is known to occur in _____ to ____ of all newborns.

Back 48

3%; 5%

Front 49

What does anlage mean?

Back 49

The initial clustering of embryonic cells from which a part or an organ develops; primordium.

Front 50

What is the difference between aplasia and agenesis?

Back 50

Aplasia: Complete absence of an organ resulting from absence of the anlage (primordial tissue)

Agenesis: Anlage is present but never develops.

Front 51

What is hypoplasia? Provide two examples.

Back 51

Anlage develops incompletely (decrease in cell production), but the tissue is histologically normal. Results in a relatively small organ. Classic example is streak ovaries in Turner syndrome. Another example is microcephaly.

Front 52

Provide three examples where loss or decrease of something causes atrophy.

Back 52

Decreased blood flow
• Cerebral atrophy due to atherosclerosis ofthe carotid artery.

Decreased innervation
• Skeletal muscle atrophy following loss of lower motor neurons in ALS.

Decreased hormone stimulation.
• Hypopituitarism causing atrophy of target organs, such as the thyroid and adrenal cortex.

Front 53

Provide two examples of pressure atrophy.

Back 53

(1) Atrophy of the renal cortex and medulla in hydronephrosis.
(2) Thick pancreatic duct secretions in cystic fibrosis occlude the lumens causing increased luminal back-pressure and compression atrophy ofthe exocrine glands and tubular epiihelium

Front 54

What is brown atrophy?

Back 54

Brown atrophy is a tissue discoloration that results from lysosomal accumulation of lipofuscin ("wear and tear" pigment), Lipofuscin is an indigestible lipid derived from lipid peroxidation of cell membranes, which may occur in atrophy and free radical damage of tissue.

Front 55

Describe a metaplasia in the urogenital tract.

Back 55

Schistosoma hematobium infection in the urinary- bladder causes transitional epithelium to undergo squamous metaplasia.

Front 56

Mainstem bronchus epithelium develops __________ metaplasia in response to irritants in cigarette smoke

Back 56

squamous