Flashcards in 1.0 Introduction to Neurones Deck (64)
What is the function of the medulla and pons?
Control regulatory systems for basic function (CVS/resp)
What is the function of the cerebellum?
Planning complex movements
What is the function of the midbrain?
Dorsal surface = tectum
Contains superior and inferior colliculi
Superior colliculi = visual processing
Inferior colliculi = auditory processing
What is the function of the thalamus?
Closely linked to cerebral cortex (specific areas of cortex are linked to thalamus)
What is the function of the hypothalamus?
Regulator of homeostasis
What is the function of the cerebral cortex?
Largest part of brain
Primary cortical areas = specialised for processing one modality
Association cortices = receive and associate info of many modalities
What is the function of the basal ganlia?
Group of nuclei under the cortex
Associated with learned selection and expression of beneficial beavhiour for a given circumstance
What is the function of the amygala?
Assessment and learning of the emotional significance of given sensory info
Function of Soma
Soma = cell body
It is the metabolic centre of the cell
Contains nucleus and ER
Gives rise to dendrites and axons
Function of Dendrites
Receive incoming signals from other nerve cells
Function of Axon Hillock
Specialised part of the soma that connects it to axon. Action potentials are initiated here because it has the lowest threshold potential
Function of Axon
Carries signals to other neurons (can convey singles from 0.1mm to 2m)
For the following ions:
What is the internal concentration, external conc. , valence, and equilibrium potential?
What is the Nernst potential?
Membrane potential at which there is no net flux of that ion across the membrane
Depends on chemical and electrical gradients
What is the Nernst equation?
At rest, what ion is the membrane mainly permeable to?
What is the Donnan equilibrium?
If a membrane is permeable to both K⁺ and Cl⁻, they will move across until their concentration gradient is balanced by membrane potential.
Therefore if equilibrium is reached:
[K⁺]i x [Cl⁻]i = [K⁺]o x [Cl⁻]o
What two secondary active processes are used to extrude Cl⁻:
Therefore ECl is usually more negative than membrane potential
What two neurons have increased internal [Cl⁻]?
1) Developing neurones
2) Adult olfactory receptor neurones
Therefore opening of Cl⁻ channels → outward (excitatory) current
3 mechanisms by which calcium is extruded from the cell?
1) ATP-fuelled Ca²⁺ pump
What are the steps for neurotransmitter release?
1) AP reaches nerve terminal
2) Opening of voltage gated Ca²⁺ channels
3) ↑ [Ca²⁺]i
4) Fusion of vesicles with membrane
What proteins are needed for vesicle fusion with plasma membrane?
1) v-SNAREs (synaptobrevin)
2) t-SNAREs (SNAP-25 and Syntaxin)
3) Synaptotagmin (Ca²⁺ sensor)
What are the stages for vesicle fusion with plasma membrane?
1) Vesicle docks at presynaptic active zone
2) Vesicle is primed by close association between v-SNAREs and t-SNAREs
3) Vesicles fuse with plasma membrane in Ca²⁺ dependent manner
3 criteria needed for a substance to be considered a neurotransmitter
1) Present at pre-synaptic terminal
2) Released during stimulation
3) Must have same effect when exogenously applied
What are the two types of neurotransmitter receptors?
- Direct mechanism of action
- Ionic channels
- Can allow Ca²⁺ influx
- Indirect mechanisms
- Uses 2nd messengers
- Effect is usually via α-subunit bound to GTP
- Can also be due to βγ (usually acting on K⁺ channels)
- Results in amplification
List 3 amino acid neurotransmitters:
List 5 biogenic amine neurotransmitters:
List 2 purine neurotransmitters:
List 2 gaseotransmitters: