LATEST UPDATED 2026
What is the #1 cause of cellular injury leading to necrosis (especially the kidney and
heart) - hypoxia
What is the #1 cause of hypoxia? – ischemia
Apoptosis - A programmed cell death that is regulated or programmed. Cellular self-
destruction for elimination or unwanted cell populations
Necrosis - Rapid loss of the plasma membrane structure, organelle swelling,
mitochondria dysfunction
Main component of a cell - nucleus
What does the nucleus contain? - nucleolus
What is the nucleolus composed of? - RNA, most of cellular DNA, DNA binding
proteins, and histones
Why are histone important? - histones bind to DNA and fold it into chromosomes
(chromatin) which is essential for cell division
What are ribosomes? - RNA-protein complexes (nucleoproteins) that are synthesized
in the nucleolus and secreted into the cytoplasm through pores in the nuclear
envelope called nuclear pore complexes (NPCs)
Where can ribosomes be found? - cytoplasm and rough ER
, what are ribosomes chief function? - provides sits for cellular protein synthesis
What is the Golgi apparatus (complex)? - a network of flatten, smooth membranes
and vesicles frequently located near the nucleus of the cell
What does the Golgi apparatus do? - takes proteins from the ER and
processes/packages them into small membrane-bound vesicles called "secretory
vesicles, and refines and directs traffic in the cell
What are lysosomes and what do they do? - maintain cellular health by removal of
toxic cellular components, removal of useless organelles, termination of signal
transduction, and signals cellular adaption
How does aging affect lysosomes? - leads to progressive loss of lysosomal efficiency
which declines the regenerative capacity of organs and tissue
What functions do lysosomal components integrate? - nutrient abundance, energy
levels, and cell stressors and will translate them into instructions that regulate cellular
metabolism toward either proliferation or inactivity
What is mitochondria responsible for? - cellular respiration, cellular metabolism , and
energy production
What does the inner membrane of mitochondria contain? - enzymes of the respiratory
chain and are essential to the process of oxidative phosphorylation that generates
most of the cell's ATP
The mitochondrial matrix contains what kind of pathways (1), involve what two things
(2), and metabolizes what three things (3)? - 1- metabolic
2- urea and heme synthesis
3- carbs, proteins, and lipids
What can accumulate intracellularly caused by stresses form metabolic
dearangements? - carbs, proteins, and lipids
What is physiologic atrophy? - occurs in early development. ex: thymus glad during
childhood
What is pathologic atrophy? - occurs as a result of decreases in workload, use,
pressure, blood supply, nutrition, and hormonal stimulation.
Ex: Shrinking of gonads in an adolescent pt in response to decreased hormonal
stimulation. and an pt immobilized in bed for a prolonged time
what is hypertrophy? - increase in cell size