Nervous system Flashcards
3 types cells in nervous system
neurons, neuroglia
3 types of neurons according fct
sensory (carry impulse to cns), motor, (carry impulse from neurons to effectors), interneurons (in learning and memory)
3 types of neurons according shape
multipolar, bipolar, (pseudo)unipolar
2 hard parts of neuron
myelin sheath and schwann cell
4 zones in a neuron
input zone, summation zone (triggers), conduction zone, output zone
nerve impulses travels along what
plasma membrane
Types of neuroglia cell and what they produce
schwann cell in PNS and oligodendrocytes in CNS
they produce myelin sheaths
3 reasons inside neuron negatively charged
1-sp pump (brongs 2 K+ in and 3 Na+ out
2-ion leakage channels (+ ions diffuse out)
3-negatively charged molecules like proteins stuck inside
CNS of sponges
phylum w/o nerves
3 basic divisions of vertebrate brains
hindbrain, midbrain, forebrain
what protects brain
skull, meninges and cerebrospinal fluid
1.4 kilo brain made of how many amitotic neurons
100 billion
What meninges made of
in order: dura master, arachnoid, pia mater
what is cerebral cortex
outer layer of cerebrum
left side brain vs right side brain
left: language logic math science
right: artistic skills
fct medulla oblongata
attaches spinal cord to maintain homeostasis
fct pons
control breading
fct midbrain
consciousness
fct cerebellum
balance, posture, smooth mvt
fct limbic system
emotional response + memory processing
fct thalamus
relays sensory impulses to cerebral cortex + memory processing (part of limbic system)
fct hypothalamus
chief integration center, regulates everything
fct pineal gland
biological clock, vraries melatonin secretion
2 types photoreceptors in retina
Rods (black/white) and cones (colour)
action potential vs graded potential
action potential: all-or-none event, occurs when treshold voltage reached (-70 to -65)
steps of action potential
1-resting state (Na+ and K+ channels closed, pump open)
2-Depolarization (only Na+ channels open so goes in)
3-Repolarization (Na+ close but K+ channels open so goes in=reverses polarity)
4-Hyperpolarization (Na+ resets, some K+ channels stay open and pump continues work)
re-establishment resting potential
…..depolarization of next region of axon…..depolarization of next region of axon
how increase velocity of conduction
1-greater axon diameter
2-action potential only at nodes of ranvier through saltatory conduction
synapses
intercellular junctions
*there are presynaptic cells and postsynaptic cells
steps of synaptic transmission
nerve impulse/action potential travels which opens Ca+ channels tiggering neurotransmitter release accross synpase to receptors on post synptic cells
how to stop synaptic transmission (3)
removing neurotransmitters from synpatic cleft
1-reuptake
2-enzyme degradation
3-diffuse
2 types of neurtransmitters and exmaples
excitatory (ACh and aa) and inhibitory
Others: epinephrine responsible for fight or flight, dopamine, seratonin
how become addicted cocaine
cocain bond dopamine to transporters so no uptake
dopamine fores more and more pleasure
prolonged exposure=reduce receptor numbers=addicted
number of reflex arc in spinal cord
3 (if needs to be quick) or 2
pns consists of
nerves and ganglia
sympathetic vs parasympathetic division symptoms
sympathetic like anxiety attach and para opposite
ear parts
outer ear:
middle ear: malleus, incus, stapes (in order)
inner ear: cochlea, semicircular canal (balance)
taste parts and involves neurons where
taste buds, papiliae
involves neurons in upper part of nasal passage where neurons transmitted to olfactory nerve
