General Content Flashcards
3 Structural functional relationships
SA, SA:V, elastic recoil
Substances that move across membranes
Molecules, solvents, fluids, gasses and heat
Things that stop flow
Increasing membrane thickness, reducing available transport proteins, decreasing tube radius and piloerection
Types of energy gradient
Heat, chemical and electrical
4 groups of tissues
Epithelium, connective, nervous and muscular
Types of Epithelium (5)
Protective, transport, exchange, secretory and cilliated
Protective epithelium
Lines organs/surfaces/cavities. Can be keratinised and stratified.
Transport epithelium
selective exchange of products, large SA. ie. villi and microvilli
Exchange epithelium
Movement of gasses across surface, poreous and flatterened.
Ciliated epithelium
Epithelia with cilia on apical surface. Cilia designed for fluid movement across surface, cilia able to produce beating action to move substances.
Secretory epithelium
Glands that secrete substances, cuboidal cells
4 components of homeostasis
- Regulator variable (thing that changes), 2. Sensor, 3. Control centre, 4. Effector
3 Homeostatic control pathways
- Extrinsic reflex feedback loop (pos neg FB loops), local control feedback loop and feedforward control
Extrinsic reflex feedback loop
Pos/neg feedback loops, maintiain body within a range of tolerance. require external control centre
Instrinsic local control
doesnt require an external control centre, control of localised disruptions
Feedforward control
Anticipatory pathway that initiates a loop prior to change/
4 functions of cell membrane
isolation of cell, structural support, communication and regulation of exchange.
Membrane proteins
Integral proteins (channels, embedded through membrane, disruptive to remove from bilayer) and peripheral proteins (attached loosely, enzymes)
Membrane lipids
Phospholipids (phospholipid bilayer, hydrophobic head and hydrophyllic head), and cholestrols (increases membrane flexibility)
Membrane protein functions
Structural, control cell movement, enzymes, receptors, cell to cell communication
Simple vs Facilitated diffusion
Simple, doesn’t require protein transport, moves lipid soluble molecules. Facilitated diffusion move ions and lipid insoluble molecules. Using channels (permanent hole) and carriers (binds to molecule and flips to change what side of membrane carrier is open to)
Types of membrane carriers
Uniport- one molecule/direction, antiport- 2 molecules/direction, symport- 2 molecules/1 direction
2 Types of active transport
Primary- Uses energy from ATP hydrolysis
Secondary- Uses energy generated from the concentration gradient of another molecule. Symports and antiports.
4 Types of cell communication
direct cell signalling, paracrine, neural and endocrine
2 Types of direct cell signalling
Gap Junction- Membrane proteins link, ion move directly from one cell to another
Contact-dependant- Membrane proteins on surface are in contact with each other, binding alters cellular function
Strength of chemical signal impacted by
Concentration of cellular messenger, number of receptors on target cell, strength of chemical-receptor bond
3 Signalling receptor types
Channel-linked receptor, Enzyme-linked receptor and G-protein linked receptor.
Paracrine messaging
Between close cells, ligand diffuses to target cell
Structural-functional relationships
Type and property of secretory cell and target cells, distance between, molecular proeprties, number of receptors
Endocrine signalling
Hormones released by cells to travel through blood stream to distant target cells
Hydrophyllic hormone action
Hormone is dissolved in plasma, cannot cross cell membrane, activates secondary messenger within the cell, binds to receptors on membrane
Lipophyllic hormone action
Not dissolved in the plasma, bound to a carrier protein for movement. Can cross cell membrane
Factors determining how long hormones are active for
Half life of the hormone, rate of degredation of the hormone, duration of secretion (concentration of the hormone)
Triggers for hormone release
Neural or Humeral via secretory epithelium
Modes of hormone release
Episodic- One release
Circadian- Timed releases that are controlled by bodies internal clock
Pulsatile- perioidic bursts
Interactions between hormones
Antagonism- One hormone decreases another
Additive_ hormones working together to produce a combined effect
Synergism- Hormones working together to produce an enhanced effect
Permissiveness- One hormone is required for another hormone to work
