1I Foundations 9 - Cellular Adaptations

Question 1

What is the underlying dysfunction in Chediak-Higashi syndrome?

Answer 1

Immunodeficiency syndrome where lysosomes of the phagocytes are ineffective

Question 2

How does having a high cholesterol content in the plasma membrane affect the function of the plasma membrane?

Answer 2

• Decreased fluidity

- Increased melting temperature

Question 3

A patient presents with an aganglionic colon and other neural crest derivative deficiencies. What other findings would you expect to see?

Answer 3

• PNS abnormalities
• Autonomic dysfunction
• Conductive hearing loss
• Anterior chamber eye problems
• Dental abnormalities
• Albinism
• Heart defects (Truncus arteriosus, Transposition of the great vessels)

Question 4

What happens cellularly in hypertrophy

Answer 4

Cells become larger by laying down more myofibrils from increased protein production

Question 5

Uterine muscle during pregnancy is an example of what kind of hypertrophy?

Answer 5

Hormone-induced

Question 6

What is the most common cause of myocardial hypertrophy?

Answer 6

Chronic hypertension

Question 7

What is the mechanism of myocardial hypertrophy caused by chronic hypertension?

Answer 7

Increased afterload –> cellular adaptation is hypertrophy –> Stiff left ventricle –> It can’t relax so can’t fill as easily.

Question 8

What does left ventricular hypertrophy lead to?

Answer 8

Diastolic heart failure

Question 9

Increase in the size of breasts because of estrogen production is an example of?

Answer 9

Hyperplasia (caused by hormonal changes)

Question 10

What is metaplasia?

Answer 10

One cell type is replaced by another cell type in response to an ongoing stressor

Question 11

What is the metaplastic change and other changes that happens in the trachea and bronchi of smokers?

Answer 11

• Ciliated columnar cells –> Squamous cells
• Less mucus production –> respiratory infections
• Transformation to cancer

Question 12

What is the metaplastic change that happens in Barrett esophagus?

Answer 12

Squamous –> Columnar (Sometimes calles intestinal because columnar is therer)

Question 13

What causes Barrett esophagus?

Answer 13

Chronic GERD

Question 14

What’s a precursor to esophageal adenocarcinoma (the most common type of esophageal cancer in the USA)

Answer 14

Barrett esophagus

Question 15

Define atrophy!

Answer 15

• Reduced size of individual cells

- Reduced number of cells

Question 16

Causes of atrophy?

Answer 16

• Decreased hormone signals (uterus/vagina)
• Decreased innervation (motor neuron damage)
• Decreased O2 supply and nutrients
• Increased hydrostatic pressure (nephrolithiasis)
• Occlusion of secretory ducts (Cystic fibrosis)

Question 17

What happens on a cellular level in atrophy?

Answer 17

• Fewer cell organelles
• Decreased metabolic activity –> Decreasedprotein synthesis
• Protein degradation by the Ubiquitin-proteasome pathway
• Autophagy and free radical oxidation

Question 18

Free radical oxidation of lipids cause some yellow-brown particles to be produced. What are they called?

Answer 18

Lipofuscin

Question 19

What are telomeres?

Answer 19

Long, non-coding DNA sequences on ends of chromosomes

Question 20

What happens to telomeres during cell division?

Answer 20

They shorten with each round of cell division

Question 21

Shorter the telomeres ..

Answer 21

older the cell

Question 22

What is the function of telomerase?

Answer 22

Elongates telomeres

Question 23

Where can you find telomerase?

Answer 23

Germ cells and stem cells

Question 24

Where can you not find telomerase?

Answer 24

Mature somatic cells

Question 25

How is a method cancer cells can stay alive forever by?

Answer 25

Expressing telomerase

Question 26

How can you make cells live longer?

Answer 26

Caloric restriction

Question 27

Does the myometrial growth in pregnancy occur primarily as a result of hyperplasia or hypertrophy?

Answer 27

Hypertrophy