NU 206 CHs 1&2; Cells

organelles

structures carry out specific cell functions to sustain life

homeostasis

regulating internal environment to maintain balance/equilibrium in response to internal/external changes

plasma membrane

semipermeable membrane made up of phospholipid bilyaer & proteins/cholesterol

deoxyribonucleic acid

genetic material, regulates cellular activity

edema

when disease alters plasma membrane’s configuration & excess fluid enters cell to cause swelling

cellular dehydration

when disease alters plasma membrane’s configuration & intracellular fluid leaks out pores to cause shrinkage

glycoproteins

antigens that ID cells as part of the body’s own tissue, as opposed to virus or foreign object

antigens

surface markers

Na+/K+ pump

K+ ions must be higher concentration inside cell, Na+ must be higher concentration outside cell

plasma membrane is more soluble to K+ ions, which allows them to leak out; less soluble to Na+ ions which keeps them out

adenosine triphosphate

energy used to constantly keep moving ions across the membrane through active transport during active transport, every 3 Na+ ions are pumped out and 2 K+ ions are pumped in

mitochondria

powerhouse of cell, converts organic nutrients into ATP

cellular aerobic metabolism

process for mitochondria to make ATP; requires oxygen; 34 ATP produced

cellular anaerobic metabolism/glycolysis

when no oxygen is available to make ATP, glucose is used; occurs outside mitochondria; produces only 2 ATP and pyruvic acid

cellular hypoxia

when cell/tissue doesn’t have enough oxygen to function properly; pyruvic acid converts to lactic acid, causing muscle cramps & other biochemical alterations

free radicals

unstable molecules created when a molecule has an odd # of electrons in the outermost shell; they damage cells by stealing electrons from other important cellular components (lipids, DNA, proteins), which disrupts function and can cause mutations, plasma membrane damage, and impaired enzyme activity

lysosomes

organelles that ingest & break down foreign substances & cell debris

autolysis

when lysosomes release digestive enzymes to destroy cell parts after cell death

macrophage

defensive white blood cells that have lots of lysosomes & ingest lots of foreign bodies

heterolysis

when lysosomes are used to digest foreign matter ingested by macrophages; lack of lysosomal enzymes = no degradation & build up of cell waste

tay-sachs disease

caused by lack of lysosomal enzymes, resulting ganglioside, which causes build up in liver, heart, NS, retina, and spleen cells = organ dysfunction

proteasomes

large group of proteins that enzymatically degrade polypeptide chains and unwanted proteins

peroxisomes

small organelles that break down long-chain fatty acids & free radicals (antioxidants)

nucleotides

organic molecules that form basic structural units of nucelic acids

purine base

nitrogenous base made of adenine and guanine

pyrimidine base

nitrogenous base made of thymine and cytosine

transcription

process by which DNA is copied to RNA; occurs in nucleus; 2 DNA strands of helical structure separate; one strand is now a template for RNA synthesis; The single RNA strand copies genetic info from og DNA molecule & leaves the nucleus to transport it to ribosomes for protein synthesis

translation

process by which RNA is used to produce proteins; occurs in ribosomes; ribosomes interpret the message from mRNA in order to manufacture proteins

codon

3 nitrogenous bases interpreted by ribosome to determine the correct sequence of amino acids that form the protein

ganglioside

build up of lipids found in nervous system

DNA nucleotides

have nitrogenous bases & a phosphate bound to a pentose (5 carbon sugar) called deoxyribose

adenine always binds with…

thymine

guanine always binds with…

cytosine

etiology

original cause of cellular alteration or disease

etiologic agents

injurious agents

hypoxia

low oxygen delivery to cells

histology

microscopic study of tissues/cells

biopsy

extracts a cell sample from an organ/tissue mass & yields diagnostic information

pathogenomonic changes

histological findings that represent distinct disease processes

atrophy

cellular adaptation where cells get weaker/smaller because environment can’t support cell’s metabolic requirements

ischemia

decreased blood flow circulation

hypertrophy

increase in cell size results in enlargement of functioning tissue mass; increases cell’s functional components=more energy needs

angiogenesis

growth of new blood vessel branches due to exercise

physiological hypertrophy

when the enlarged muscle is adequately supplied w blood flow, O2, & nutrients due to angiogenesis

pathological hypertropy

when there is an increase in cell size but not in supportive structures needed for enlarged cell’s metabolic needs

hyperplasia

increase in the # of cells in tissues/organs

only in cells capable of mitotic division (epithelial or glandular tissue)

stimulated by hormonal or compensatory cellular mechanisms

stem cells

self renewing cells

metaplasia

replacement of one cell type by another cell type; result of cell’s genetic reprogramming in response to change in environmental conditions

neoplasia

new growth; disorganized, uncontrolled proliferative cancerous cell growth

benign

non cancerous, does not spread

malignant

cancerous and can spread to nearby tissues/organs

basic changes of cell damage

disfunction of Na+/K+ pump or calcium pump

loss of plasma membrane integrity

defects in protein synthesis

intracellular accumulation

cellular edema

DNA damage

dysplasia

cellular growth w/in a specific tissue; usually result of chronic inflammation or precancerous condition

apoptosis

genetically programmed cell death

oncogenes

radiation damaged, mutated genes that trigger cancerous cell changes

causes of cell injury categories

hypoxic, free radical, physical agents, chemical, immunological reactions, genetic defects, nutritional imbalances, infectious agent

hypoxic cell injury

most common cellular injury; when blood can’t deliver enough O2 to cells; ischemia, anemia

free radical cell injury

physical agents of cell injury

gunshot wounds, burns, frost bite, radiation, sunburn, etc

chemical cell injury

injure plasma membrane & access cell’s interior to cause disfunction of organelles; imbalances in electrolytes, Na+ levels, etc

injurious immunological reactions

when immune system attacks own cells; allergies, autoimmune diseases

genetic defects

damage/mutate DNA= cell injury

nutritional imbalances

starvation=insufficient protein; obesity=fat stores stressing heart; malnutrition=no enzymatic reactions

infectious agent injury

microorganisms (fungi, viruses, bacteria, parasites)

vascular endothelial growth factor

substances secreted by endothelium (aka angiogenesis growth factor; stimulates synthesis of collateral blood vessel branches

endothelin

protein that helps regulate BP by constricting blood vessels

hypertension

exerts a shearing force against endothelial cell membrane= many injured areas on interior walls of arteries

aneurism

weakened area in arterial wall that gets weaker with pulsatile force of hypertension = rupture

hyperglycemia

high blood glucose levels; stimulates endothelin = arterial narrowing

angiotensin II

protein that causes small arteries to constrict (=High BP), triggers adrenal glands to release aldosterone, & pituitary glands to release antidiuretic hormone

atherogenesis

gradual progressive development of plaque in arteries initiated by endothelial injury = inflammation & WBCs

inflammatory changes cause less dilating ability in arteries = LDL-C deposition & clot formation

necrosis

cell/tissue death due to injury; irreversible

cell can’t maintain homeostasis, goes dysfunctional, & can affect neighboring tissues on the whole organ

infarction

aka ischemic necrosis; death of tissue due to prolonged ischemia

gangrene

when bacteria grows in dead tissue after necrosis

transplantation

surgical intervention replaces irreversibly injured cells, tissues, & organs w viable donor tissue

stem cell transplant

embryonic stem cells for tissue repair & cell regeneration

obtained from human IVF embryos that can’t be used for infertility treatment

therapeutic cloning

combo of cloning technology & stem cell research to create transplant organs