Normal Cells and ECM Flashcards
What accounts for 50-60% of total cell volume
Cytosol
Mitochondria
Oxidative phosphorylation takes place and it release energy in the form of ATP. Has its own genome
RER
Makes proteins contains ribosomes
SER
Produce lipids and detoxification reactions
Golgi
Packages things from the ER to the surface
Lysosomes
degrade macromolecules and extracellular materials. Contains hydrolases
Peroxisomes
Contains catalase and detoxify H2O2 and break down fatty acids
Cytoskeleton
Gives cell its shape. Made of microfilaments, microtubules, intermediate filaments and regulatory proteins
What regulates assembly and disassembly of cytoskeleton
Calcium
3 embryonic cell types
Ectoderm, mesoderm, endoderm
Ectoderm
Forms cephalic disc and neural tube. CNS and PNs, sensory epithelium and epidermis derived from this
Mesoderm
Somites next to neural tube. CT, muscle, kidney, heart and blood vessels derived from this
Endoderm
Flat disc by ectoderm. GI and respiratory epithelium, liver, pancreas, and endocrine glands derived from this
How do cells interact
- Membrane pumps and enzymes
- Receptors
- Cell to cell connections
- Exocytosis
- Endocytosis
Mechanisms for cell to cell interaction
- Autocrine
- Paracrine
- Endocrine
Components of the ECM fall into what categories
- Structural
- Absorptive
- Adhesive
Structural components of ECM
- Collagen
- Elastin
Types of collagen
I- structural in most tissues
II- Cartilage component
IV- basement membranes
Absorptive components of ECM
- Glycosaminoglycans
- Proteoglycans
Adhesive components of ECM
- Fibronectin
- Laminin
Fibronectin
Cell adhesin that links cell membrane integrins to ECM
Laminin
Component of basement membranes that binds cell membrane integrins
Components of intercalated disks
- Desmosomes
- Fascia adherens
- Gap junctions
Damage to intercalated discs
Results in arythmia, ventricular hypertrophy, and cardiomyopathy
How are enterocytes linked
- Desmosomes
- Adheren junctions
- Gap junctions
- tight junctions
Damage to enterocyte tight junctions
Leaky intestines can cause loss of fluids and diarrhea as well as bactermia and hyper sensitivity due to antigen exposure as well as metabolic disorders
Mechanisms of cell aging
- Altered gene expression
- Telomere shortening
- Progressive metabolic injury
Morphology of aging cells
- Irregular nuclei
- Vacuolated mitochondria
- Reduced ER
- Lipofuscin
- Accumulation of metabolic products
Apoptosis
Active process that remove damaged or unneeded cells through a programmed physiological cell death
Apoptosis causes
- Patterned death during embryogenesis
- Maintain balance in growing pop
- removal of cells after they’ve done their job
- Removal of self-reactive lymphocytes
Mechanism of apoptosis
- Initiation phase
- Execution
Initiation phase of apoptosis
Extrinsic: Fas-FasL pathway leading to procaspase 8
Intrinsic: loss of Bcl-2 and Bcl-x, mitochondria leak cytochrome C and Bax, Bak and Bim and activates procaspase 9
Execution phase of apoptosis
After initiation caspases mediate the cleavage of structural and functional cell proteins causing cell death
Pro-apoptotic proteins
- Bax, Bak, Bim
- Smac/DIABLO
Anti-apoptotic proteins
- Bcl-2 and Bcl-x
- IAP
Apoptotic morphology
- Cell shrinkage
- Condensation of cytoplasmic and nuclear components
- Formation of membrane bound vesicles
- no inflammation
What can cause apoptosis
- Unrepaired DNA damage
- Heat
- Hypoxia
- Viral infection
- Physical pressure
