IMMS Flashcards
Mitochondria
o double membrane o cristae o matrix (Kreb’s cycle) o inner membrane (oxidative phosphorylation o produces ATP
Endoplasmic reticulum
o rough – ribosomes for protein production
o smooth - lipid production
Golgi apparatus
o receives proteins and lipids from endoplasmic reticulum
o modifies and packages them into vesicles for transport
Vesicles
o lipid bilayer
o 3 types – lysosome, secretory and transport vesicles
Cytoskeleton
o Function - keeps cell shape and organises parts of cell o Structure: ▪ Microtubules ▪ microfilaments (actin) ▪ intermediate filaments
Cell energy storage
o lipofuscin is droplet deposits around nucleus (increase with age)
o lipid droplets found mainly in adipose tissue
o glycogen is main cell storage of glucose
Cell membrane
o phospholipid bilayer o interspersed with proteins, carbohydrates and cholesterol o function: ▪ protects the cell from outside, ▪ selectively permeable to ions ▪ transport in and out of cell
Transporter proteins
o Transmembrane
o move substances in and out of cell vie facilitated diffusion or active transport
● Desmosome:
Desmosomes
o specialised for cell to cell adhesion
o protein complexes found in the cell membrane of epithelial cells
Cell surface receptor
o bind to external ligand and convert extracellular information into intracellular information
o 3 types:
▪ ion channel - opens
▪ G protein - activates protein to open ion channel
▪ enzyme linked - receptor linked to intracellular enzyme
Endocytosis
(movement into cell)
- Molecules bind to receptors in clathrin-coated pit in cell membrane
- pits bud to form clathrin-coated vesicles
- vesicle fuses with intracellular endosome
- contents are either transported to lysosome or recycled into cell membrane
Exocytosis
out of cell
Diffusion
movement of a molecule from an area of high concentration to an area of low concentration (down conc gradient)
Facilitated diffusion
normal diffusion through a transmembrane protein – useful for large/polar molecules
Active transport
movement of molecules against concentration gradient – requires ATP
Homeostasis
the maintenance of stable internal conditions within the body
Cell communication
o autocrine - within same cell
o paracrine - signal affects nearby cells
o endocrine - signal secreted into blood
Feedback
o positive = amplification of process – chain reaction)
o negative = result of action inhibits another action
Water distribution within the body- 42kg
2/3 (28kg) Intracellular F
1/3 (14kg) ECF:
-3L= plasma
-11L= interstitial fluid
Osmoregulation
- low water levels detected by hypothalamic osmoreceptors
- Osmoreceptors sends signal to pituitary to release ADH
- ADH travels to kidney and causes increased fluid uptake
Fluid loss
o sensible can be measured - urine, faeces, breathing
o insensible cannot - evaporation from skin
Osmolality -
concentration of solutes in plasma PER KG OF SOLVENT
Osmolarity
concentration of solutes in plasma PER LITRE OF SOLUTION
Osmotic pressure
CHECK!!!!!
how easily solution can take in water vs oncotic pressure: specific type of osmotic pressure concerning albumin
is a form of osmotic pressure induced by proteins, notably albumin, in a blood vessel’s plasma (blood/liquid) that displaces water molecules, thus creating a relative water molecule deficit with water molecules moving back into the circulatory system within the lower pressure venous end of capillaries.
Oedema
increased movement of fluid from plasma to interstitial space, or decrease in vice versa
Types of oedema
o normal - increased hydrostatic pressure forces fluid out of vessels
o inflammatory - histamine increases blood vessel permeability
o lymphatic - lymph system doesn’t remove fluid from extracellular space
o hypoalbuminaemic - decreased albumin = decreased oncotic pressure