Week 18 Flashcards

Question

What does the CSF do?

Answer 1

Physical support of neural structures Excretion and "sink" action Intracerebral transport biologically active substances Control of chemical environment of the central nervous system

Answer 2

External carotid arteries extend up the side of the neck, Internal carotid arteries branch into skull and circulate blood to the front of the brain Veretebral arteries follow the spinal column into the skull, they join together at the brainstem forming basilar artery, supplies blood to rear end of brain Circle of willis (loop of artieries) Connects anterior and posterior circulations of the brain

Answer 3

Duramater: 2 layers being the oeriosteal layer (lines cranium) and meningeal layer Space between those layers have veins and artieries supplying blood to brain Arachnoid mater: Thing weblike connective tissue CSF is below arachnoid mater Pia Mater: Thing membrane, close contact with brain's surface, rich with veins and arteries

Answer 4

Declines with age: Declarative memory Working memory Processing speed Problem solving Selective + Divided attention Stays the same: Procedural memory Learning new tasks Improve: Verbal abilities, spatial reasoning, maths, abstract reasioning

Answer 5

At age 6, brain 90% of adult volume Brain starts to shrink and cerebral cortex thins from 30s Cortical density decreases as synaptic connections decrease in frontal lobes and parts of temporal lobe myelinated nerve fibres shrink with age, processing slows down Chemicals that affect neurotransmitters and production of proteins decrease, cognitive function decreases

Answer 6

Number of synapses drop, affects learning and memory Dendrites shrink, less complex branching in prefrontal cortex and hippocampus Loss of dendritic spines Decline of Neurogenesis Less neurotransmitters are produced

Answer 7

Distorted representation of the human body based onto the brain (parietal lobe) based on a neurological map of areas and proportions of the braind edicated to processing motor or sensory functions of the different parts of the body

Answer 8

Influenced by genetics and environment 40 Genes contribute as well as prental environment and cultural influences

Answer 9

Twins that when facing eachother, appear as matching reflections if a split in embryo occurs later tha usual in embryos development, it already has a right side and a left side Twins that form in this situation are mirror image twins

Answer 10

Action potentials (long and short distance) Graded potentials (Short distance only)

Answer 11

Resting membrane potential Presence of membrane ion channel

Answer 12

Leakage ion channels: Allow K+ and Na+ ions to leak in/out Na/K pump: Pump Na+ out of cells and K+ into cell (Need ATP) Other ion channels will open in response to stimuli

Answer 13

Unequal Cannot

Answer 14

Small build up of negative charges along inside surface of membrane and an equal buildup of positive charges along outside surface of membrane

Answer 15

When membrane potential of axon reaches threshold, Na+ channel activation gates open. Na+ Ions move through these channels into neuron. buildup of positive charges forms along inside surface of membrane, it becomes depolarised

Answer 16

Na+ Channel inactivation gates close K+ Channels open Membrane starts to become repolarized as some K+ leave neuron and negative charges begin to build up along the inside surface of the membrane

Answer 17

K+ outflow continues, more K+ leaves neuron and more negative charge builds up along inside surface of membrane K+ outflow eventually restores resting membrane potential Na+ Channel activation gates close and inactivation gates open Return to resting state when K+ gate closes

Answer 18

Influx of Na+ detected by adjacent area of membrane Triggers voltage gated Na+ Channel to open in adjacent area of membrane Process repeated along axon, depolarisation followed by repolarisation

Answer 19

When threshold for AP is not reached Uses mechanical and chemical ion channels Amplitude depends on stimulus' strength GPs can add together to make a bigger decrease in membrane potential (Summation)

Answer 20

Generate a graded potential by allowing specific ions to flow across the membrane upon deformation of the membrane

Answer 21

When a neurotransmitter (like acetylcholine or glutamate) binds to the receptor, the channel opens, allowing ions to flow and causing a graded potential.

Answer 22

Action potential operates based on an all or nothing principal, graded potentials vary in size and duration

Answer 23

1) Neurotransmitters (NT) synthesised, stored in vesicles 2) Action Potential arrives at presynaptic terminal 3) Voltage-gated Ca2+ channels open, allows influx of Ca2+ 4) Ca2+ allows vesicle docking an NT release 5) NT binds to receptors , channels open/close 6) Excitatory/Inhibitory postsynaptic potential is generated 7) Neurotransmitter is removed by gilial uptake or enzymatic degradation 8) Vasicular membrane is retrieved from the plasma membrane IMPULSE CONTINUES

Answer 24

The vesicle comes into close contact with the membrane , "docks" at a specialized region. This is where SNARE proteins come into play: v-SNAREs (on the vesicle) and t-SNAREs (on the target membrane) bind tightly like Velcro to hold the vesicle in place. When an action potential arrives, Ca²⁺ ions enter the cell and trigger the fusion of the vesicle with the membrane—releasing neurotransmitters into the synaptic cleft.