Transmits sensory information to the CNS and produces facial and skeletal movements.
What does the autonomic nervous system do?
consists of sympatheric (fight and flight) and parasympatheric (rest and digest) --> handles arousing vs. calming functions
What are the four layers of protection for the brain?
1. Bone: (Brain protected by the skull
2. Meniges: (Dura mater (outer)
Arachnoid membrane (middle)
3. Cerebrospinal Fluid (CSF): cushions the brain and spinal cord
continually being made and drained intothe circulatory system.
4. Blood Brain Barrier: (comprised of cells of capillaries tightly joined with one another
prevents blood-borne subtances circulating in the body from crossing into the CNS)
What are the 5 components of a neuron?
1. Dendrites
2. Soma
3. Axon Hillock
4. Axon
5. Axon Terminal
What are dendrites and what do they do?
SpineBranching filaments of a neuron
What is the soma?
The cell body
What is an Axon
single neruonal process that transmits information away from the cell
Axon Hillock is...
the site of origin of a nerve impulse
What is the ARP (Absoulte Refractory Period)
The voltage gated sodium channels are open/inactive and depolorization/repolorization -- nothing you do can trigger another action potential
What is the RRP?
During the RRP the voltage channels are returning to the closed state
What is a synaptic cleft?
Small space between the axon terminal andthe post synaptic membrane of the receptor cell
What is a presynaptic membrane
membrane of the axon terminal
Postsynaptic membrane
Contrains receptor molecules that recieve chemical messages from the presynaptic cell
What is EPSP
Excitatory postsynaptic potential: causes a depoloarization (+ions flow into neruron) of the postsynaptic target
Inhibitory postsynaptic potential (IPSP)
Causes a hyperpolarization (+ions flow out of neuron) of the postsynaptic target
Neurotransmitters decativation occurs in 3 ways
1. Reuptake (reabsorption of a neurotransmitter by a transporter of a presynaptic neruron)
2. Enzymatic degradation
3. Diffusion
What is a synapse?
Connection between neurons and other cells
What is a synaptic cleft?
Space between neurons
Axon terminal is...
the end of an axon
What are the 5 types of glial cells?
1. Ependymal cell: (Samll
2. Astrocyte: (Star shaped
symmetrical; nutritive and support function)
3. Microglial: (Small
mesodermally derived; defensive function)
4. Oligodendrogilial cell: (Asymmetrical; forms insulating myeling around axons in brain and spinal cord)
5. Schwann cell: (Asymmetrical; wraps around peripheral nervs to form insulating myelin)
Cytoarchitecture differs across regions and layers of the cortex. T/F?
T
Why do we divide the brain intoanatomical regions (Brodmann areas)
Because of reginonal differencs in the cytoarchitecture of neurons
Gray matter is comprised of ...
cell bodies and capillaries
Afferent neurons carry information ...
toward (recieve)
Efferent neurons carry info ...
Away (send)
White matter is...
axons covered with glial cells
A tract is...
a large collection of axons
Nucleus/nuclei are ...
many neruons grouped together (distinctively gray)
Dorsal Root of the spinal cord has what types of fibers? These fibers carry sensory information where?
Afferent (receiving)
Ventral Root of the spinal cord has what types of fibers? These fibers carry sensory information where?
Efferent (sending)
The SNS recieves what type of information? Is largely voluntary or involuntary?
Sensory & Voluntary
The Brain Stem consists of what three areas?
1. Hindbrain
2. Midbrain
3. Diencephalon
The forebrain consists of what three parts
1. Basal Ganglia
2. Limbic Lobe
3. Cerebral Cortex
The brainstem begins where?
begins where the spinal cord enterst the skull
The Hindbrain consists of what four parts?
1. Cerebellum
2. Reticular Formation
3. Pons
4 . Medulla
The cerebullum is associated with?
Learning and coordinateing/ sequencing skilled movements; posture and balance
The pons is responsible for?
sleep-wake regulation; locomotion
The reticular formation does what?
Maintains general arousal/consciousness
The Medulla does what?
maintains vital body funtctions (respirations
The midbrain consists of two main stuctures?
1. Tectum (roof) (located dorsally)
2. Tegmentum (floor) (located ventrally)
The tectum consists of what two structures and what are they responsible for?
1. Superior colliculi: processes visual input
2. Inferiro colliculi: processes auditory input
Colliculi mediate responese to what type of input and what is their function?
Sensory inputs
The tegmentum (floor) is comprised of what three parts and what is their purpose?
1. Red nucleus: controls limb movement
2. Substania nigra: dopaminergic neruons
invovled in reward
3. Periaqueductal gray matter - controls species specific behavior (eg. sexual behavior)
modulates pain response
The diencephalon consists of what three structures and what are their functions?
1. Hypothalamus: (Involvely in nearly all aspects of motivated behavior (eg. hunger
2. Epithalamus: (Poorly understood - involved in bio-rhythms
huger
3. Thalamus: (Relays incoming (afferent) senesory information to appropiate targets; relays infomraiton between cortical areas; relays information between forebrain and brainstem.
Major Portions of the Brain include ...
1. Cerebrum
2. Cerebllum
3. Brainstem
The forebrain consists of what 3 main structures and what are their functions?
1. Basal (Involuntary motorl control
2. Limbic Lobe (Amygdala
Hippocampus
3. Cerebral Cortex (neocortex; 80% of the human brain
The Basal Ganglia and Limbic lobe are subcortical
Limbic Lobe consists of what 4 structures and what are their purposes?
1. Amygdala: (Emotion and species typical behaviors)
Neocortical regions are connected by four types of axon projections
what are they?
2. Relatively short connections btween one part of a lobe and anoother
3. Interhemispheric (bridging) connections between homotopic pointsin contralateral hemispheres
4. Connections btween cortical areas through the thalamus
Axon fibers make what 3 types of connections?
1. Connections between one lobe of the brain to another
2. one part of a lobe to another part
3. one hemishpere of the brain to another
What is an action potential?
The signal that goes through the axons going from place to another place.
Are cations negative or positive?
positive (Na+. K+)
Are anionos negative or positive
negative
What is depolorization?
When membrane channel opens and positive sodium ions rush into the cell and change the membrane potential and make them positive. This is the first phase of the action potential.
What happens in the second phase of the action potential? (Repolarization)
After Na+ comes in the charge is very very positive
What is the first stage of the action potential?
Depolarization
What is the second phase of the action potential?
Repolarization
What is the last phase of the action potential?
Hyperpolarization
What is hyperpolarization?
As K+ escapes we overshoot and go lower than the resting membrane potential. Becomes OVERpolarized.
Sodium Potassium Pump does what?
Pumps 3 Na+ ions out and 2 K+ ions in and bring the potential back to its resting state.
Synaptic Vesicles contain what?
Neurotransmitters
What is the pre-synaptic membrane?
Membrane that comes right before the space (synaptic cleft)
Membrane that comes after the synaptic cleft?
post-synaptic membrane
Reuptake:
reabsorption of a neurotransmitter by a transport of a presynaptic neuron. Allows recyling of neurotransmitters
What are the 7 major neurotransmitters?
1. Acetylcholine (ACh): PNS; activates muscules // CNS; forms the cholinergic sytem
2. Dopamine (DA): CNS; voluntary movement
learning
3. Norepinephrine (NE):
4. Serotonin (5-HT)
5. Gamma-amino butyric acid (GABA)
6. Glutamate (Glu)
7. Endorphins: produce feelings of wellbeing
Why are we able to make color discriminations in bright light?
Because of the increased density of cone cells in the fovea
What augments sensitivity to light?
Increased density of rod cells in the peripheral retina
Light enters the eye through the ...
cornea
Light is focused by the lens on recptors in the ...?
retina
receptors in the retina are called?
photoreceptors
What are the two types of photoreceptors?
1. Rods: (Sensitive to dim light -> night vision); located in peripheral retina (absent in fovea)
2. Cones: (sensitive to bright light -> day and color vision (densely packed in the fovea)
Rods are sensitive to what type of light and help with what vision?Are they present in the fovea?
dim
Cones are sensitive to what time of light? Help with what vision? Are they present in the fovea?
bright
How does vision work in terms of transduction of energy?
Light is convereted into cehmical energey in the photoreceptors
How does audition work in terms of transduction of energy?
Air pressure waves are converted into mecanical energy. Mech energy actives aduitory ereceptor cells which then produce action potentials
What are the three parts of the ear?
1. Outter
2. Middle
3. Inner
How does audition work?
1. Sound waves vibrate teh tymapnic membrane (eardrum)
2. Three bones in the ear pass vibrations to the cochlea
3. Cilia make contact with tectorial membrane
4. When hair cells are excited by virateion a nerve impulse is generated in the auditory nerve
5. Information is then sent to the brain and interpreted as sound
What is the tympanic membrane and what does it do
Eardrum
What are the 3 ossicle bones in the middle ear?
1. Incus
2. Stapes
3. Malleus
What does the inner ear consist of?
1. cochlea (hearing)
2. vestibular system (balance)
What contains the receptors for auditory stimuli?
cochlea
What are hair cells embedded in the organ of corti?
auditory receptors
The vestibular system is different from the cochlea how?
cochlea deals with hearing
ventral cochlear nucleus is different from the dorsal cochlear nucleus how?
ventral is the longer route
Homunculus means?
little human
Vestibular system is located where and allows us to do what?
inner ear
what does the vestibular system consist of?
1. otolith organs: (repsond to linerar acceleration
2. semicircular canals: (can respond to any movement of the head)
What is V1 and what BA does it correspond to?
1. primary visual cortex (striate cortex)
2. BA 17
V2
V3
2. BA 18 and 19
What BA make the occipital cortex
BA 17
BA 17
18
2. VA 1-5
V1 is what? Recieve input from what?
1. Primary visual cortex
2. Recieve input from lateral geniculate nucleus
Located in middle of occipital lobe
V1 neurons respond to
small differences in visual orientation
Doral Stream is know as the [blank] pathway? Why?
1. where pathway
2. associated with object location and control of the eyes when information is used to guide reaching.
Ventral Stream is know as the [blank] pathway? Why?