Nervous System Flashcards
Frontal lobe
- responsible for conscious thought (attention)
- initiates voluntary skeletal muscle movement via motor cortex
- contains olfactory bulb for smell
- broca’s area for speech formation
- prefrontal cortex for decision making and planning
Temporal lobe
- processes and interprets sounds
- wernickes area: understanding speech
- hippocampus: memory formation
- auditory cortex: processes auditory information
Occipital lobe
- processes and interprets visual input
- responsible for object recognition
- responds to visual stimuli
- contains the visual association cortex: processes vision
Parietal lobe
- contains the sensory areas:
- somatosensation: temperature, touch, pressure, and pain
- proprioception: orientation of body parts in space
- somatosensory cortex: recieves and processes sensory information from entire body
Midbrain
Relay center for visual and auditory impulses and motor control
Pons
Relays messages between the forebrain (cortex), cerebellum, and medulla
Medulla oblongata
- regulates heart, breathing rate, blood pressure and gastointestinal activity
- Toxin sensing
- Connects the cerebrum/cerebellum to the spinal cord
Function of ependymal cells
Line the ventricles of the brain, circulating cerebrospinal fluid through sweeping motions of their ciliary projections (parts of the CNS)
What is another term for motor neurons?
Efferent neurons
Where do efferent (motor) neurons emerge from?
The ventral root of the spinal nerves
What is another term for afferent neurons?
Sensory neurons
Where do afferent (sensory) neurons emerge from?
The dorsal root of the spinal nerves
The telencephalon gives rise to:
The cerebrum
The diencephalon gives rise to:
The thalamus, hypothalamus and pineal gland
The mesencephalon gives rise to:
The midbrain
The metencephalon gives rise to:
Pons and cerebellum
The myelencephalon gives rise to:
Medulla oblongata
The forebrain develops into:
Telencephalon and diencephalon
The midbrain gives rise to:
Mesenchephalon
The hindbrain gives rise to:
The metencephalon and myelencephalon
What is the absolute refractory period due to?
- Inactivation of voltage-gated sodium channels
- sodium ions cannot enter the neuron to produce another action potential
- another action potential cannot be fired no matter how powerful the stimulus
- sets upper limit to action potential frequency
Absolute refractory period:
Refers to a period of time after the initiation of the action potential during which another action potential cannot be generated, no matter how strong a stimulus is
Sodium channels open - sodium channels close and are inactivated (no other action potential can be generated when channels are inactivated) - potassium channels open
Relative refractory period:
Refers to the period after the action potential fires during which a stronger than normal stimulus could cause another action potential to be fired - this is the period that happens during hyperpolarization
Sodium channels reset to original state - potassium channels begin to close
path of vision:
cornea –> pupil –> lens –> retina
sclera
- connective tissue that surrounds the eye for protection
- avascular
- (white outer layer of the eye)
choroid
- layer just below the sclera
- vascular connective tissue layer between the sclera and the retina
- provides blood and nutrients to the retina
what is the function of rhodopsin?
a pigment that is in the rods of the retina which, when struck by photons of light, it causes hyperpolarization of rod cells –> bipolar and ganglion cells in the retina will also become active and the neural action potential is sent to the brain
photoreceptor cells synapse with ________ cells, which receive input from rods and cones to transmit the signal to the ________ cells
bipolar
ganglion
the sympathetic nervous system has a ____ preganglionic neuron and a ____ postganglionic neuron
short
long
the parasympathetic nervous system has a ____ preganglionic neuron and a ____ postganglionic neuron
long, short
what does the preganglionic neuron of the sympathetic nervous system release?
acetocholine
what does the postganglionic neuron of the sympathetic nervous system release?
epinephrine/norepinephrine
what does the preganglionic neuron of the parasympathetic nervous system release?
acetylcholine
what does the postganglionic neuron of the parasympathetic nervous system release?
acetylcholine (and sometimes nitric oxide
myopia
nearsightedness
hyperopia
farsightedness
astigmatism
irregularaly shaped cornea
cataracts
lens becomes opaque and light cannot enter
somatic nervous system:
- innervates skeletal muscle
- can be voluntary or involuntary
- uses Ach at neuromuscular junction
autnomic nervous sytem:
- responsible for involuntary movement
- innervates cardiac and smooth muscle
- divided into parasympathetic and sympathetic braches
axon hillock
- where the soma connects to the axon
- action potentials are generated here
dendrites
- recieve information and transfer it to the cell body
axon
- transfers impulses away from the cell body
what are neurons highly dependent on for chemical energy?
glucose –> use facilitated transport to move glucose from the blood and into the cell but is not dependent on insulin for transport
glial cells
- nervous tissue support cells that are capable of cell division
microglia
- phagocytes of the CNS
ependymal cells
- use cilia to circulate cerebralsprinal fluid
satellite cells
- groups of cell bodies in the PNS
- serve to support cells
astrocytes
- provide physical support to neurons of the CNS
- maintain the mineral and nutrient balance
hindbrain
- posterior part of brain
- contains the: cerebellum, pons, medulla, and brainstem
cerebellum
- maintains balance
- hand-eye coordination
- timing of rapid movement
- motor skills
brainstem
- consists of the midbrain, medulla, and pons
- connects the cerebrum with the spinal cord
- part of reticular formation: network of neurons within the brainstem that regulate sleep and arousal
dorsal horn
sensory info enters here
ventral horn
motor info exits here
