Cell Size- Changes

Question 0

How do cytoplasmic protein concentrations change when the cell undergoes atrophy?

Answer 0

Synthesis of certain proteins stop, Well degradation of certain proteins increase.

Question 1

Name the seven potential causes of atrophy?

Answer 1

Aging, chronic disease, ischemia, malnutrition, decreased functional demand, interruption of trophic signals, increased pressure.

Question 2

How does gene expression change during cell atrophy?

Answer 2

Selective decreases in transcription.

Some genes that mediate protein degradation are upregulated.

Question 3

What are the causes of hypertrophy? Which ones are physiologic in nature?

Answer 3

Increase functional demand, trophic signals, mechanical stretch, growth hormones

Cardiac hypertrophy:
Exercise-physiological
Increased vascular resistance- pathological

Question 4

What are the cellular responses to increased hypertrophy signals?

Answer 4

Increased protein degradation
increased protein translation
increased gene expression,
survival- inhibition of cell death
ancillary functions- modification of extracellular matrix
recruitment a satellite cells- fuse with other cells to increase nuclei

Question 5

How does endurance and resistance training effect cardiac and skeletal muscle cells hypertrophy?

Answer 5

Endurance training- no hypertrophy. leads to increase in amp:ATP ratio–>increase in slow myosin H chains

Resistance training- hypertrophy. Increase in fast myosin H chains.