Term
| what are some differences between afferent, efferent, and interneurons? |
|
Definition
Afferent neurons -Inform CNS about
external /internal conditions
• Efferent neurons -instructions from
CNS to effector organs (muscles,
glands)
• Interneurons
– Within CNS
– Integrate afferent
information ,
formulate
efferent
response
– Higher mental
functions |
|
|
Term
| what are neuroglia cells and what are their function? |
|
Definition
Physically, metabolically, and functionally support
interneurons (90% of CNS cells)
• Major types (astrocytes, oligodendrocytes/Schwann
cells, microglia, ependymal cells) |
|
|
Term
| what are some properties of astrocytes? |
|
Definition
“Glue” of CNS – holds neurons
together
– Guide neurons during fetal
development
– Aids establishment of blood-brain
barrier (BBB)
– Repair brain injuries, neural scar
formation
– Neurotransmitter activity
– Take up excess K
+
from brain
ECF
– Enhance synapse formation and
modify synaptic transmission |
|
|
Term
| what are some properties of oligodendrocytes or schwann cells |
|
Definition
myelin sheaths around
axons in CNS/PNS |
|
|
Term
| what are some properties of ependymal cells |
|
Definition
Line internal, fluid-filled
cavities of the CNS
– In ventricles of brain, help
form and circulate
cerebrospinal fluid |
|
|
Term
| what are some properties of microglia |
|
Definition
Immune cells of CNS
(macrophages)
– Release low levels of growth
factors/cytokines facilitate
neuronal/ glial growth |
|
|
Term
| how is the CNS protected? |
|
Definition
cranial cavity, dura mater, arachnoid mater (filled with CSF), pia mater, CSF (cushioning and nutritional fluid)
blood brain barrier limits access of blood borne materials |
|
|
Term
| where is the CSF secreted, and absorbed? |
|
Definition
| Formed primarily by choroid plexuses, reabsirbed in the dural sinuses |
|
|
Term
| what is the BBB, blood brain barrier? |
|
Definition
| The blood–brain barrier (BBB) is a separation of circulating blood from the brain extracellular fluid (BECF) in the central nervous system (CNS). It occurs along all capillaries and consists of tight junctions around the capillaries that do not exist in normal circulation |
|
|
Term
| know the locations of the midbrain, pons, medulla, cerebellum, forebrain, diencephalon and telencephalon. |
|
Definition
|
|
Term
| what are the properties and functions of the midbrain |
|
Definition
Cranial nuclei III-IV
• Cerebral peduncles –cerebrum to lower levels
• Superior/inferior colliculi
• Substantia nigra (dopamine – basal ganglia)
• Red nucleus – rubrospinal tracts (lower species)
• Reticular formation starts - large, diffuse network |
|
|
Term
| what are the properties and functions of the pons |
|
Definition
Relay area
• Pontine nuclei – projection to cerebellum
• Cranial nuclei (V-VII) |
|
|
Term
| what are the properties and functions of the medulla |
|
Definition
Pyramidal decussation
Cranial nuclei – VIII-XII
Visceral motor function (CV,resp)
Upper/lower airway reflexes |
|
|
Term
|
Definition
| these cells come down from the cerebral cortex and cross over at this pyramidal decussation, so this is where the left brain cross its signals over to control the right side of the body. |
|
|
Term
| what is the function of the brain stem? |
|
Definition
Autonomic regulation – regulate heart and blood vessel function,
respiration, GI functions |
|
|
Term
| what is the reticular formation and what is its function? |
|
Definition
Dorsal brainstem (clustered neurons/netlike fibers)
– Modulatory (serotonin, norepinephrine, cholinergic, dopamine)
– Ascending integration of sensory input, limbic system
(mood/emotion/pain), sleep-arousal
– Descending - Muscle reflexes, equilibrium/posture, visceral
modulation |
|
|
Term
| what are the properties and functions of the cerebellum? |
|
Definition
Interlimb coordination, balance,
specific types of motor learning,
motor planning and execution
– Vestibulocerebellum –
balance and eye movements
– Spinocerebellum – muscle
“tone” (partially), comparator
– Cerebrocerebellum
• Plays role in planning and
initiating voluntary activity by
providing input to cortical motor
areas
• Stores procedural memories
Attached at top rear portion of brain stem
• Maintains proper position of the body in space
• Subconscious coordination of motor activity (movement)
• Key role in learning skilled motor task |
|
|
Term
|
Definition
| it compares what you wanted to do to what you actually did. |
|
|
Term
| what are the parts of the diencephalon and what is the thalamus functions? |
|
Definition
(Hypothalamus/Thalamus)
– primitive sensory processing
– “relay station”, processing towards
cortex
– direct attention to stimuli of interest
(brainstem and cortex)
– crude awareness of sensation
(cannot distinguish
location/intensity) |
|
|
Term
| what is the function of the hypothalamus? |
|
Definition
Controls homeostatic functions
important in maintaining stability
of internal environment
– Functions (body temperature,
food/water intake, urine output,
hormonal secretion (many),
major ANS center,
emotional/behavioral,
sleep/wake cycle |
|
|
Term
| what is the limbic system? |
|
Definition
Portions of hypothalamus and other forebrain structures
(ring of gray matter on medial cerebral hemispheres)
– Emotion (behavior/memory/learning)
– Reward and fear systems
– Motivation/learning
Specific electrical stimulation of nuclei within amygdala
produce emotional behaviors
• Subcortical structures |
|
|
Term
| what is the cerebrum/telencephalon? |
|
Definition
Makes up about 80% of total brain weight (largest portion of brain)
• Inner core houses basal nuclei
• Outer surface is highly convoluted cerebral cortex
– Highest, most complex integrating area of the brain
– Plays key role in most sophisticated neural functions |
|
|
Term
| what is the function of the Basal nuclei/basal ganglia |
|
Definition
Initially thought to be solely motor functions (gross
motor/oculomotor)
• Cognitive/learning
• Emotion/limbic system |
|
|
Term
| what are the four major lobes of the cerebral cortex? |
|
Definition
Occipital lobe – initial visual processing
– Temporal lobe – initial sound sensation
– Parietal lobe – somatosensory, sensory integration
– Frontal lobe – volitional, speech, cortical/logical processing |
|
|
Term
| what are the 6 well defined cerebral cortical layers? |
|
Definition
I – molecular layer mostly
axons
– II – External granule layer
(stellate cells)
– III – external pyramidal
layer (pyramidal – to
subcortical)
– IV – Internal granule layer
– V – internal pyramidal
(giant pyramidal cells -descending)
– VI – multiform layer
(receive thalamic input,
project other lamina)
– V-VI – stellate cell – to
subcortical regions |
|
|
Term
| thick layer 4 in the post central gyrus in the parietal because it is receiving tons of input from the .....? |
|
Definition
| sense of touch, somatosensory! |
|
|
Term
I and II are ???
III to subcortical
IV input from afferent sources
V output to other areas
VI projects upwards |
|
Definition
|
|
Term
| what are the roles of the sensorimotor cortex? |
|
Definition
Primary motor cortex (M1)
– commands to lower levels for
initiation/ modulation of movement
to contralateral side
– specific trajectory planning
– Motor programs located here or at
interneuron networks
• Primary somatosensory cortex (S1)
– provides sensory information for
movement planning/initiation
– modulation of ongoing movement |
|
|
Term
| what is the motor homunculus? |
|
Definition
Location/amount of
cortex devoted to
output to muscles |
|
|
Term
| what is the sensory homunculus? |
|
Definition
Location/amount of
cortex devoted to
sensory input from
periphery |
|
|
Term
| what is the premotor area? |
|
Definition
involved in goal-directed
movements
– Activity prior to visually-guided
movements |
|
|
Term
| what is the supplementary motor area? |
|
Definition
ensures correct sequencing of
movement (order of movement)
• biomechanical constraints
• task performed
• external conditions
– Activity prior to internally-guided
movements |
|
|
Term
| what is the posterior parietal cortex? |
|
Definition
Posterior parietal cortex
– encodes complex sensory
information
– internal sensory representation |
|
|
Term
| what is the composition and function of the occipital lobe? |
|
Definition
primary visual cortex (ocular dominance columns - bilateral input)
Association cortices - interpretation/recognition of movement/color |
|
|
Term
| what is the composition and function of the temporal lobe? |
|
Definition
primary auditory/sound sensation (tonotopic map)
association cortices - dominant (wernicke's) - damage = comprehension difficulty
non-dominant - difficulty in understanding tone of voice
-gustatory cortex, vestibular processing as well |
|
|
Term
| what is the composition and function of the frontal lobe? |
|
Definition
broca's area - generating language
dominant - written or spoken
non-dominant - difficulty generating tone
frontal eye fields - conjugate eye movement. |
|
|
Term
| brocas and wernickes areas. how do these areas work together to affect speech processing and speech initiation? |
|
Definition
Broca’s area – speech output
– Wernicke’s area
• language comprehension
• formulating coherent
patterns of speech
• Processing:
1) Integration visual/auditory,
association cortices
2) Information to Wernicke’s
area (choice/sequence of
words are formulated)
3) Info to Broca’s area,
message to sound pattern
4) Program conveyed to primary
motor cortex to allow motor
output |
|
|
Term
| what are the parts of the prefrontal cortex? |
|
Definition
dorsal prefrontal cortex - memory judgement, planning, sequencing of activity, abstract reasoning and dividing attention.
Ventral/inferior prefrontal cortex - impulse control, personality, reactivity to surroundings or mood
medial prefrontal - cingulate gyrus (associated with limbinc system)
lesions in these areas would result in: poor temporal/spatial memory, personality changes, aggressiveness/impulsivity. |
|
|
Term
| what are some left brain and right brain associations? |
|
Definition
left = Logical, analytic,
sequential,
\verbal tasks
• Math,
• language
forms
• philosophy
Right = Nonlanguage skills
• Spatial
perception
• artistic/ musical
talents |
|
|
Term
| is the corpus callosum white matter or gray matter? what is its function |
|
Definition
| all white matter (tracks), integration of right vs left brain activities |
|
|
Term
| what is a really dumbed down schematic of sensorimotor processing? |
|
Definition
| sensory input --> primary sensory areas --> higher sensory areas --> association areas --> higher motor areas --> primary motor cortex --> motor output |
|
|
Term
| what is the sympathetic ganglion chain? |
|
Definition
The bilaterally symmetric sympathetic chain ganglia, also called the paravertebral ganglia, are located just ventral and lateral to the spinal cord. The chain extends from the upper neck down to the coccyx, forming the unpaired coccygeal ganglion. Preganglionic nerves from the spinal cord synapse at one of the chain ganglia, and the postganglionic fibre extends to an effector, a visceral organ in the thoracic cavity, abdominal cavity, or pelvic cavity.
There are usually 22-23 pairs of these ganglia: 3 in the cervical region, 11 in the thoracic region (note the presence of the stellate cervicothoracic ganglia), 4 in the lumbar region and 4-5 in the sacral region. Throughout human evolution, the first thoracic and inferior cervical ganglia merged - and this resulting ganglia is called the "stellate". |
|
|
Term
| what are the functions of the spinal cord? |
|
Definition
-Communication between brain and PNS (somatic and autonomic) –
descending/ascending pathways
– Incoming sensory input/motor outputfrom most of body (except BS
– Integration of sensorimotor information (simple reflex to complex
motor behaviors, integration from descending input |
|
|
Term
| what happens at the lateral horn? |
|
Definition
| soma of autonomic efferent cells. |
|
|
Term
| What are reflex responses? |
|
Definition
Stereotypical response to similar afferent input
• Not hardwired; modulated by other neural inputs/pathways
• Any response that occurs automatically without conscious effort
– Occurs locally at SC or BS, transmit through multiple INs,
ascending/descending tracts |
|
|
Term
| what are the two types of reflexes? |
|
Definition
- Simple (basic, unlearned, genetic)
- Acquired (conditioned) |
|
|
Term
| what are the 5 basic components of the reflex response |
|
Definition
Receptor
- Afferent pathway
- Integrating center
- Efferent pathway
-Effector |
|
|
Term
| what lobe would have the biggest layer IV? |
|
Definition
| parietal lobe. IV affects afferent |
|
|
Term
| what lobe would have the biggest layer V |
|
Definition
| frontal cortex (MOTOR output, pyramidal cells) |
|
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