What is the PNS comprised of?
Somatic and Autonomic nervous systems
What does the somatic nervous system do?
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, the spinal cord is encased in a series of interlocking bony vertabrae) 2. Meniges: (Dura mater (outer), Arachnoid membrane (middle), pia mater (inner) 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, they receive information from other cells
What is the soma?
The cell body, central part of the cell containing the nucleus
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, but only a few channels will be closed so it requires a very strong stimulus to trigger a new action potential.
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, encloses the synaptc vesicles that contain neurotransmitters
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, most neurons don't connect physically.
Axon terminal is...
the end of an axon, forms the presynaptic protion of the synapse. Is close to the dendritic spine of a neighboring neuron.
What are the 5 types of glial cells?
1. Ependymal cell: (Samll, ovoid; secretes CSF) 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?
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 ...
Efferent neurons carry info ...
White matter is...
axons covered with glial cells
A tract is...
a large collection of axons, aka. a fiber pathway (distinctively white)
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), sensory to the brain
Ventral Root of the spinal cord has what types of fibers? These fibers carry sensory information where?
Efferent (sending), motor information to the body
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. Diecephalon
The forebrain consists of what three parts
1. Basal Ganglia 2. Cerebral Cortex 3. Limbic Lobe
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, heart rate etc.)
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. Inferior colliculi: processes auditory input
Colliculi mediate responese to what type of input and what is their function?
Sensory inputs, and they orient us to visual and auditory signals.
The tegmentum (floor) is comprised of what three parts and what is their purpose?
1. Red nucleus: controls limb movement 2. Sustantia nigra: dopaminergic neurons, involved in reward, control of movement 3. Periaaqueductal 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,thirst, sexual behavior) 2. Epithalamus: (Poorly understood - involved in bio-rhythms, huger,thirst) 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. Cerebellum 3. Brainstem
The forebrain consists of what 3 main structures and what are their functions?
1. Basal Ganglia (Involuntary motor control, habitual learning action selection (selecting the correct action at the correct time) 2. Limbic Lobe (Amygdala, Hippocampus, eptum, Cingulate Cortex) 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) 2. Hippocampus: (Memory and spatial navigation) 3. Septum: (Emotion and special typical behavior) 4. Cingulate Cortex: (Affectively-related cognitive processing) EMOTION
What are the four lobes of the cerebral cortex?
1. Occipiatal 2. Parietal 3. Temporal 4. Frontal
Neocortical regions are connected by four types of axon projections, what are they?
1. Long ipsilateral connections between one lobe and another (fasciculi) 2. Relatively short connections between one part of a lobe and another 3. Inter-hemispheric (bridging) connections between homotopic points in contralateral hemispheres 4. Connections between 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
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, because the membrane potential is that positive, the voltage gated potassium channels open and K+ escapes because it wants the charge to be negative. This is repolarization.
What is the first stage of the action potential?
What is the second phase of the action potential?
What is the last phase of the action potential?
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?
What is the pre-synaptic membrane?
Membrane that comes right before the space (synaptic cleft)
Membrane that comes after the synaptic cleft?
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, role in the enchancement of sensory perceptions sustaining memory and attn. 2. Dopamine (DA): CNS; voluntary movement, learning, cognition, motivation and reward 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 ...
Light is focused by the lens on recptors in the ...?
receptors in the retina are called?
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, night vision, not present in fovea
Cones are sensitive to what time of light? Help with what vision? Are they present in the fovea?
bright, day vision/ color, yes present and densely packed.
How does vision work in terms of transduction of energy?
Light is convereted into cehmical energey in the photoreceptors, then converted into action potentials
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 the 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, it vibrates in response to sound waves and changes acoustical energry into mechanical energy.
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?
What are hair cells embedded in the organ of corti?
The vestibular system is different from the cochlea how?
cochlea deals with hearing, vestibular system is for balance
ventral cochlear nucleus is different from the dorsal cochlear nucleus how?
ventral is the longer route
little human, associated with disportionate sizes; larger area = higher sensitivity
Vestibular system is located where and allows us to do what?
inner ear, percieve our own motion and maintain balance
what does the vestibular system consist of?
1. otolith organs: (repsond to linerar acceleration, sensitive to changes in the position of the head) 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, V4, and V5 are what? What BA do thy corespond to?
1. Estrastriate cortex 2. BA 18 and 19
What BA make the occipital cortex
BA 17,18, and 19
BA 17, 18, and 19 are what? and What VA are they?
1. Occiptial Cortex 2. VA 1-5
V1 is what? Recieve input from what?
1. Primary visual cortex 2. Recieve input from lateral geniculate nucleus
Located in the middle of occipital lobe
V1 neurons respond to
small differences in visual orientation, spatial frequency and color
Doral Stream is know as the [blank] pathway? Why?
1. where pathway 2. Recieve input from lateral geniculate nucleus
Ventral Stream is know as the [blank] pathway? Why?
1. What pathway 2. Associated with form and object recognition
What is the hippocampus responsible for?
consolidation of long-term memories
What is the amygdala responsible for?
adding value and meaning to memory, and response
Broca's area is located where?
Frontal lobe, just about the STG
Wernicke's area is located where?
Just infront of the occipital lobe, ventral to parietal, dorsalto temporal.
Broca's and Wernicke's area are along what gyrus?
The superior temporal
Cool EF refers to what?
Higher level cognitive control; working memory, planning etc.
Personality is what lobe?
Hot EF refers to what
Affectively laden judgment and behavioral control