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Mod1Wk1- Lec 3
Terms in this set (32)
What are the 4 tissue types?
Epithelial, connective, muscle, nervous
What are characteristics of epithelial tissue?
Function: protection, absorption, secretion, and excretion
-covers most of the internal and external body surfaces; has cilia and microvilli
What is simple squamous tissue? (epithelial)
location: (flat) lines all major organs
function: absorption, exchange of materials, filtration, secretion
What is simple cuboidal tissue? (epithelial)
location: lines tubules and ducts of glands
function: absorption and secretion
What is simple columnar tissue? (epithelial)
location: GI tract
function: absorption and secretion
What is stratified squamous tissue? (epithelial)
location: lines the interior of mouth, esophagus, vagina
What is transitional tissue? (epithelial)
location: urinary bladder
function: confers elasticity
What are characteristics of connective tissue?
Function: framework for forming organs, binding, supporting, and storing excess nutrients
-Has few cells surrounded by matrix, has a gelatinous goo called ground substance, fibers within the ground substance (collagenous-white, elastic-yellow, and reticular)
-found in cartilage, bone, vascular, adipose, and organs
What are characteristics of muscle tissue?
Function: contractile tissue, enabling both voluntary and involuntary movement.
-composed of myocytes
-ex) smooth, skeletal, cardiac
What are common causes of cell injury?
-lack of oxygen (hypoxia)
-caustic or toxic chemicals
What are common results of cellular injury?
-depletion of ATP (cell swelling, less protein synthesis)
-oxygen depletion (ischemia, ROS)
-calcium homeostasis (inc in cytosolic calcium levels- caspases)
-membrane permeability (lets in particles, lose electric potential)
What is mitochondrial respiration?
Biomolecules are catabolized and the end process in the mitochondria transfers electrons used to create the energy, the end recipient of the electrons is oxygen, which is reduced, creating water
How are free radicals created?
Incomplete reduction of oxygen creates reactive oxygen species;
super oxide (O2-) > hydrogen peroxide (H2O2) > hydroxyl radical (H2O + OH) > water (H2O)
What are free radicals and ROS?
Electrically uncharged atom or group of atoms having an unpaired electron
-The unpaired electron is prone to bonding with other biomolecules, attaching to them and changing their chemistry/structure, which impairs their function
-The accumulation of damage permanently damages them
What are reactive nitrogen species (RNS)?
-peroxynitrate generated with the reaction of superoxide radical with nitric oxide; this quickly reacts with carbon dioxide, forming ONOOCO2-
-peroxynitrate or degradation products of the ONOOCO2- acts as ROS do, attaching to biomolecules and altering their chemistry/structure and function
What is lipid peroxidation?
ROS damages lipids and disrupt the cell membrane; phototherapy hemolysis of RBCs
What is protein oxidation?
ROS attaches to proteins, altering their chemical structure, function and stability; aging
What is DNA oxidation?
ROS attaches to DNA, changing structure, blocking synthesis and inducing mutations; cancer
What damages to DNA can ROS cause?
1. form base pairs with nonstandard base pairings (mutagenesis)
2. may inhibit DNA synthesis and transcriptional complexes (trigger apoptosis)
What do antioxidants do? Examples?
Scavenge free radicals;
-superoxide dismutase (targets superoxide, O2-)
- glutathione peroxidase (targets hydrogen peroxide, H2O2)
-uric acid, vitamin C, vitamin E
What is hypoxia?
A lack of oxygen; ischemia and anoxia
What is ischemia?
Lack of blood flow into vessels that supply the cell with oxygen and nutrients
What is anoxia?
Total depletion of oxygen in the environment
What are cellular responses to hypoxia?
Decreases in ATP, causing failure of the Na+/K+ pump and sodium-calcium exchange, cellular swelling
What is reperfusion injury?
Burst of oxygen and nutrients from reperfusion after ischemia/anoxia causes oxidative damage and inflammation
Cellular injury can lead to cell death by...?
-decreased ATP production
-failure of active transport mechanisms
-ribosomes detach from ER
-cessation of protein synthesis
-lysis of plasma membrane
How do cells adapt to stress?
Cells response is to escape and protect itself from injury by;
-atrophy, hypertrophy, hyperplasia, metaplasia, and dysplasia
What is atrophy and what causes it?
Decrease in cell size
What is hypertrophy?
Increase in the volume of an organ or tissue due to the enlargement of its component cells (not cell division)
What is hyperplasia?
Caused by an increased rate of cellular division, often occurs in the same organs undergoing hypertrophy
What is metaplasia?
Reversible replacement of one mature cell type by another less mature cell type; often occurs as a stem cell is reprogrammed due to the environment, and physiologically, the replacement isn't as functional
What is dysplasia?
Deranged cellular growth; is not a true cellular adaptation but rather an atypical hyperplasia
-refers to abnormal changes in the size, shape, and organization of mature cells
-can progress to be cancer
Sets found in the same folder
Mod1Wk1- Lec 1
Mod1Wk1- Lec 2
Mod1Wk1- Lec 4
Mod1Wk2- Lec 1
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