Cellular Adaptation Flashcards
Cellular Adaptation to Nonlethal Injury
- Alteration in size
- Increase in number
- Change in differentiation
Atrophy
Decrease in size of existing cells
Hypertrophy
Increase in size of existing cells
Hyperplasia
Increase in number
Metaplasia
Change in differentiation
A 42 year old man comes to the clinic with a 1 year history of a burning sensation to the chest and a 6 month history of odynophagia (painful swallowing). He has a history of gastroesophageal reflux disease (GERD). Physical examination shows no abnormalities. Biopsy from upper endoscopy shows metaplastic changes of the esophageal epithelial cells. He is given a diagnosis of Barrett’s esophagus. Which of the following processes would more than likely have accounted for the initial cellular response to stress observed in this patient?
Adaptation.
The biopsy sample from the same patient, MJ, was examined at a higher magnification under light microscopy. The cells were noted to have vacuolated cytoplasm. Which of the following cellular responses to injury is most likely being described?
Hydropic degeneration.
Early cellular responses to injury
- Cloudy swelling:
- Hydropic degeneration:
- Fatty change (steatosis):
Cloudy swelling
-Earliest evidence of injury
-Loss of normal staining intensity due to swelling of organelles
Hydropic degeneration
-Continued swelling of organelles
-Vacuoles appear in cytoplasm
-Stains faintly with loss of basophilia
Fatty change
Steatosis
-Accumulation of triglycerides in cytoplasm
-Most common in liver
-Rarely in cardiac & skeletal muscle
-Common causes: Toxins, Alcohol, Chronic hypoxia
A 21 year old girl comes to see her physician for a wellness checkup. She recently joined her high school athletics team about 2 months ago. Physical examination reveals no abnormalities but shows a 2 cm increase in her mid-arm circumference and a 3 cm increase in her mid-thigh circumference. Her laboratory investigations were within normal limits. Which of the following cell adaptations is most likely responsible for her physical examination findings?
Hypertrophy.
Hypertrophy
Increase in the size of cells which can result in increased size of organ: Reversible
No change in cell number
Cause: Increased functional demand & specific hormonal stimulation
Tissues commonly affected by hypertrophy:
1) Cardiac muscle: increased demand, hypertension
2) Skeletal muscle: increased workload, exercise
3) Uterus: Hormonal, pregnancy
A 43-year old man is brought to the emergency department because of extreme fatigue, weight loss, abdominal pain, and darkening of his skin (hyperpigmentation). On physical examination, he has a low blood pressure. Blood tests reveal low blood sugar (hypoglycemia). He is a bodybuilder who has been using steroids for 10 years. The doctor explains to him that his symptoms are due to loss of endocrine stimulation of his adrenal glands which led to reduced adrenal function. Which of the following cellular adaptations is most likely in this patient?
Atrophy.
Atrophy
Reduction in functional cell mass: -Decreased size & Function of cells
-Reversible
Causes of Atrophy
1) Decreased functional demand
2) Decreased blood supply
3) Loss of innervation
4) Loss of endocrine stimulation
5) Nutritional deficiency
6) Aging
Tissues commonly affected by Atrophy
1) Testis in elderly
2) Skeletal muscle: Disuse, Loss of innervation
3) Brain:
Neurodegenerative, Aging
A 45 year old man comes to the clinic because of a 1-month history of progressively worsening difficulty to urinate described as straining to initiate and maintain the urinary stream. It is associated with a weak, interrupted urinary flow and increased urinary frequency. Physical examination shows an enlarged, non tender, nodular prostate of normal consistency on digital rectal examination. Laboratory tests shows elevated prostate-specific antigen (PSA) levels. A biopsy of the prostate gland is obtained and shows an increase in the number of epithelial and stromal cells. Which of the following best characterizes the histopathological findings in this patient?
Hyperplasia
Hyperplasia
Increase in the number of cells: reversible
-Cause: increased functional demand, hormonal stimulation
Compensatory hyperplasia
increase in tissue mass after damage or partial resection (Ex. liver)
Tissues commonly affected by Hyperplasia
1) Endometrium: Hormonal stimulation
2) Prostate gland: hormonal stimulation
3) Red Blood Cells: High altitude
4) Glandular epithelium of breast: hormonal stimulation
5) Uterine enlargement: Pregnancy
Hyperplasia of endometrium
1) Normal proliferative phase endometrium: normal estrogen stimulation
2) Hyperplasia of endometrial glands: example from woman on hormone replacement therapy
A 35 year old man is brought to the emergency department because of blunt trauma to his leg in a construction site accident. Seven months later, a radiography showed bony tissue in the muscle at the injury site. This condition is an example of which of the following adaptations to cellular injury?
Metaplasia
