Neural Communication, Membrane potenial and Action potentials Flashcards
(24 cards)
Within neural communcations, what are some disadvantages and advantages of endocrine and neural receptors towards their target cell?
Endocrine receptors are located all over the body but the message is passed rather slowly.
Neural receptors are very direct and INSTANT!
Explain afferent neurones, interneurons and efferent neurones, where they are located and how they work.
Afferent neurones are the sensory neurones and they travel into the CNS where the interneurons will then send the message to the efferent neurone to do the specific motor action needed.
What determines the RMP?
The relative permeability of the membrane to ALL ions.
Changes in the permeability of the membrane to any ion results in a change in the membrane potential of that cell.
What are the two types of membrane potentials?
graded and action
Whats the response of the AP as you go higher and higher above the threshold?
The greater the AP frequency.
What are the five different receptors that convert the different information into APs
Mechanoreceptors - physical change in shape Thermoreceptors - hot and cold Nociceptors - pain Electromagnetic receptors Chemoreceptors
Monosynaptic vs. Polysynaptic reflex arcs
Monosynaptic reflexes are faster, and dont use multiple synapses or interneurones.
Polysynaptic use multiple synapses and therefore uses an interneurone.
Two diff in skeletal muscle compared to smooth and cardiac
Skeletal muscle is attached to bone and it brings about movement of the skeleton. and it is voluntary, regulated by the somatic NS. .
More: multi-nucleated with nuclei on the peripheral, it is striated.
myofibrils
Allow the muscles to contract.
Crossbridge
Link between the myosin head and actin molecule
isometric examples and definition
Ex: leg squats against wall, holding a 3lb steel ball out in front of you until you can no longer hold it.
Def: load increases as muscle contracts. Cross bridge cycle provides tension.
isotonic examples and definition
ex: bicep curls
Def: lenth decreases but load remains constand. Crossbridge cycle provides movement.
What is the mammalian cell cycle?
S, G2, M, G1
What does stratified squamous cells protect against? Give example.
Protection against moderate abrasion.
Esophagus
What do transitional or urothelium cells do?
made to strech and recoil, like the bladder.
Simple Squamous
They have a low resistance to flow, like blood vessels.
Simple columnar epithelium with microvilli (brushborder)
Main goal is absorption.
What is the main goal of simple cuboidal cells?
A secretory role.
Ex: a secretory role of endocrine gland
What do stratified squamous keratinized epithlium do?
Protect against a high amount of abrasion, like a dogs footpad.
What does a psuedostratified (ciliated) columnar epithelium (with goblet cells) focus on doing? What is an example?
They are involved with cleansing (cilllia) and moistening (goblet cells). The respiratory system.
What is going on in G2?
Cells are preparing for mitosis. Checkpoints are checking for mistakes. Was the DNA replicated completely? The cell is about to divide into two cells.
Quiescence
Term for when cells are in G0 phase. This is the non-dividing state. Most adult cells are in G0.
An increase in the extracellular [Ca] results in an increase in the strength of contraction of skeletal muscle fibres.
FALSE - skeletal muscle uses intracellular Ca for excitation contraction!
A reduction in the extracellular Ca concentration decreases the excitability of nerve and muscle fibres?
FALSE - The RMP of a cell reflects the distribution of ions across the cell membrane. Ca is normally higher in ECF than ICF, therefore if low EC Ca that means high Intracellular Ca (more positive), closer to threshold, MORE excitable.
