Revision Flashcards
Neurons have a neuronal cell body, dendrites to receive incoming or outgoing signals (?) and axons that receive incoming or outgoing signals (?)
incoming
outgoing
What kind of cells are neuroglia?
supporting cells such as schwann cells
TRUE or FALSE: the myelin sheath protects and electrically
insulates the axon, preventing
charge leakage
TRUE
the nodes of ranvier are ???
Myelin sheath gaps between Schwann cells
There is a higher concentration of Na+ or K+ (?) ions on the outside of the cell compared to inside
Na+ ions
the inside of a membrane is negative or positive?
negative
Polarisation: the membrane is active or at rest? (neurons approx. -70mV)
at rest
Depolarisation: membrane potential less negative or positive?
eg: -70mV to +30mV
less negative
TRUE or FALSE:
Hyperpolarisation: membrane potential more negative than resting polarized potential (-70mV to -90mV)
TRUE
Depolarization – Inside of the membrane becomes less or more (?) negative than the resting potential
less
Repolarization – Inside of the membrane becomes negative or positive (?) toward resting potential
negative
Leakage (non-gated) ion channel are always ???
open
chemically gated channels are open in response to binding a ??? chemical to the receptor
neurotransmitter
Voltage gated ion channels are opened in response to changes in ??? potential
membrane
during repolarising phase, signal reaches peak, Na+ channels close and K+ channels open:
K+ flows out of cell = More -ve near inside or outside (?) of cell membrane
Inside of cell
Mechanically gated ion channels—open and close in response to ??? of receptors
physical
deformation
The CNS determines stimulus intensity by the ??? of impulses
frequency
during the depolarising phase, Na+ channels open: Na+ flows down concentration gradient into cell = More +ve near inside or outside (?) of cell membrane
= Membrane potential becomes positive
inside of cell
what is the time from the opening of the Na+ channels until the resetting of the Na+ channels called?
absolute refractory period
TRUE or FALSE: During hyperpolarisation some K+ channels remain open, allowing excessive K+ efflux. to get back to resting conditions, K+ close, some Na+ channels open
TRUE
Relative refractory period refers to when most Na+ channels have returned to their resting state, some K+ channels are still open and Repolarisation or hyperpolarisation (?) is occurring
Repolarisation
Presynaptic neuron— conducts impulses toward or away (?) from the synapse
towards
Postsynaptic neuron—transmits impulses away from or towards (?) the synapse
away from
the Synaptic Cleft is a fluid-filled space separating the presynaptic and postsynaptic neurons that prevents ??? from directly passing from one neuron to the next
nerve impulses
Action Potential arrives at axon terminal of the presynaptic neuron,
opens voltage-gated Ca2+ channels. Ca2+ influx promotes fusion of synaptic vesicles with axon membrane and ??? occurs into synaptic cleft. Neurotransmitter diffuses and binds to receptors (often chemically gated ion channels) on the postsynaptic neuron. Ion channels are opened = event in the cell
Exocytosis of neurotransmitter
ridges on cerebral hemispheres are known as: gyri or sulci?
gyri
the longitudinal or transvere fissure separates the two cerebral hemispheres?
Longitudinal
the central sulcus separates the
pre-central gyrus of the frontal lobe and the postcentral gyrus of the ??? lobe
parietal
the cerebral cortex is the sight of the ??? which includes awareness, sensory perception, voluntary motor initiation, etc
conscious mind
The transverse or longitudinal cerebral fissure separates the cerebrum and the cerebellum
transverse
the types of functional areas of the cerebral cortex include:
- motor areas
- sensory areas
- ???
association areas
the meninges contain ??? and forms partitions in the brain
cerebrospinal fluid
what are the three layers of the meninges?
dura mater, arachnoid mater, pia mater
which of the meninges layers is the strongest and made of two layers (periosteal + meningeal) of fibrous connective tissue. Also helps form sinuses
dura mater
the three parts of the dura mater include:
- falx cerebri
- falx cerebelli
- ??? cerebelli
tentorium
which meningeal layer is the middle layer, has web-like extensions, and is separated from the dura mater by the subdural space?
arachnoid mater
the subarachnoid space or subdural space holds CSF and blood vessels?
Subarachnoid space
which meningeal layer is a layer of delicate vascularised connective
tissue that clings tightly to the brain?
pia mater
The ??? ventricle is located in the hindbrain (brainstem), dorsal to the pons and medulla
fourth ventricle
TRUE or FALSE: the Third ventricle is located in the diencephalon (thalamus)
TRUE
Functions of the CSF include:
– Buoyancy to the CNS organs
– Protects the CNS from blows and other trauma
– Nourishes the brain and carries ???
chemical signals
TRUE or FALSE: the volume of CSF is not constant
FALSE. It IS constant
CSF is produced by the ??? of each ventricle at a constant rate. They hang off the roof of each ventricle
choroid plexus
Blood Brain Barrier is composed of three layers starting from the capillary:
- Continuous endothelium of capillary walls
– Thick ??? externally surrounding capillary
– Feet of astrocytes (recall neuroglia)
basal lamina
Ependymal cells use ion pumps to control the composition of the ??? and help cleanse ??? by removing wastes
CSF
the BBB is ineffective against lipid-soluble or lipid-insoluble (?) substances (membranous), including alcohol, nicotine, and anaesthetics
lipid-soluble
TRUE or FALSE: the BBB is strategically absent in some areas, eg, vomiting centre, where it is necessary to monitor the chemical composition of the blood
TRUE
The peripheral nerbous system includes:
12 pairs of cranial nerves
??? pairs of spinal nerves
31
sensory neurons are afferent or efferent (?) with information coming in
afferent
motor neurons are afferent or efferent (?) with information going out
efferent
autonomic neurons are made of a 2 neuron chain:
1. Preganglionic neuron:
spinal cord -> ganglion
2. Postganglionic neuron:
ganglion -> effector or affector (?) tissue
effector
TRUE or FALSE: ganglions are the synapse between two neurons in the peripheral nervous system
TRUE
Preganglionic neurons are slightly or heavily myelinated? releases acetylcholine
slightly
Postganglionic neurons are myelinated or unmyelinated? they release either acetylcholine or norepinephrine
unmyelinated
Postganglionic neuron: effect on target organ is either inhibitory or excitatory dependant on receptor type and ???
neurotransmitter
Hypothalamus: Projects to medulla
to control ??? function
autonomic
Medulla Oblongata:
- Regulates: breathing, heart rate
and blood pressure
- Reflexes: coughing, swallowing
and ???
vomiting
the sympathetic NS has long or short preganglionic neurons and the opposite for postganglionic neurons?
short preganglionic neurons, long postganglionic
Parasympathetic NS has long or short (?) preganglionic neuron and the opposite for postganglionic neuron
long preganglionic neuron
short postganglionic neurons
neurons that release acetylcholine are cholinergic or adrenergic neurons?
cholinergic
neurons that release epinephrine and norepinephrine are cholinergic or adrenergic?
adrenergic
Adrenergic receptors: NE binds to ⍺1 receptor on arteries = vasoconstriction or vasodilation?
vasoconstriction
adrenergic receptors: NE binds to β2 receptor on lungs = dilate or constrict bronchi?
dilate
Nicotinic receptors sit on ion channels: allowing ions to flow in/out of the cell= ???
response
Fast, immediate
Muscarinic receptors are positioned on target organs for ??? NS = Inhibitory OR excitatory (dependent on receptor subtype)
PNS
Muscarinic receptors stimulate downstream effects inside the cell = ??? effects
Slower, longer lasting
