Anatomy, Development + Placticity Of Nervous System Flashcards
(30 cards)
1
Q
Terminology
A
Lateral—- toward line
Medial— towards midline
Dorsal—- towards back
Ventral— towards stomach
Anterior—- towards front end
Posterior— towards rear end
2
Q
Anatomical directions in humans
A
Directions in cerebral hemispheres rotated 90 degrees in comparison to those in spinal cord
3
Q
Parts of Peripheral Nervous System
A
- Anatomical nervous system
- Somatic nervous system
4
Q
Anatomical nervous system
A
- regulates body’s internal environment
- controls involuntary muscles (heart)
- afferent: internal sensory signals to CNS
- efferent: motor signals from CNS to internal organs
- unconscious and automatic
5
Q
Somatic Nervous System
A
- interacts with external environment
- controls voluntary muscles
- conveys sensory info to CNS
- afferent: from skeleton muscles to CNS
- efferent: motor signals from CNS to Skelton muscles
- conscious + voluntary
6
Q
Anatomic Nervous System
A
- Sympathetic nervous system
- Parasympathetic Nervous System
7
Q
Sympathetic nervous system
A
- Prepares organs for vigorous activity (fight to flight)
- increases breathing + heart rate
- decrease digestive activity
8
Q
Parasympathetic Nervous System
A
- promotes energy-conserving
- non-emergency functions
- generally does opposite of sympathetic activities
9
Q
Spinal Cord
A
- within Sinai
10
Q
Peripheral nervous system
A
- Autonomic nervous system
- Somatic nervous system
11
Q
Autonomic nervous system
A
- regulates body’s internal environment
- controls involuntary muscles (heart)
- afferent: internal sensory signals to CNS
- efferent: motor signals from CNS to internal organs
- unconscious and automatic
12
Q
Somatic nervous system
A
- interacts with external environment
- controls voluntary muscles + conveys sensory info to CNS
- afferent: internal sensor signals to CNS
- efferent: motor signals from CNS to internal organs
- conscious and voluntary
13
Q
Autonomic nervous system
A
- Syntactic nervous systems
- Parasympathetic nervous system
14
Q
Sympathetic nervous system
A
- prepares roams fro vigorous activity (fight or flight)
- increases breathing + heart rate
- decreases digestive activity
15
Q
Parasympathetic nervous systems
A
- promotes energy- conserving
- non-emergency functions
- generally does opposite of sympathetic activities
16
Q
Spinal cord, what does it do?
A
- within spinal column
- communicates with sense organs + muscles below head
- segmented structure
- if cut, brain looses sensation from that segment and all below
- simple, reflexive behaviors can take place on level of spinal cord
17
Q
The 3 major divisions of the brain:
A
- Forebrain
- Midbrain
- Hindbrain
18
Q
Hindbrain
A
- traits carrying signals between rest of brain + body
- controls some vital reflexes (breathing, heart rate)
- reticular formation —> plays important role in arousal, sleep, attention, movement, cardiac + articulacy responce
- pons: axons from each side of hemisphere cross
- cerebellum: also involved in cognitive functions (eg attentional shifts, timing)
19
Q
Midbrain
A
Tectum:
- SC: visual function
- IC: auditory function
Tegmentum:
- sensorimotor functions, part of system that deteriorates in Parkinsons disease
20
Q
Forebrain
A
- largest division of human brain
- initiates voluntary movement, interprets sensory inputs mediates complex cognitive processes
- contains hypothalamus: important for regulation of motivate behaviour + regulates release of hormones
- main parts: cerebral cortex, basal ganglia, limbic system
21
Q
Basal ganglia
A
- several structures playing major role for voluntary motor responses
Eg.
- Globus pallidus = one target for deep brain stimulation in Parkinson’s —> electrodes implanted deep inside brain —> targeted brain regions electrically stimulated —> result= reduction of tremor
22
Q
Limbic system
A
- regulation of motivated behaviours + emotions
- amygdala, hippocampus, cortex+ others
23
Q
Cerebral cortex
A
- outer surface of cerebral hemispheres
- deeply convoluted to increase surface of cortex
Neurons communicate across hemispheres, mainly through corpus callosum
24
Q
Each hemisphere within forebrain is divided into 4 lobes….
A
- Occipital lobe
- main input from thalamic nuclei that receive visual input
- posterior pole: primary visual cortex (VI)
- destruction of VI causes blindness - Paternal Lobe
- area posterior to central sulcus
- postcentral gyrus: receives main input from touch sensations + muscle stretch receptors - Frontal Lobe
- areas anterior to central sulcus
- precnetral-gyrus: movement control
- anterior portion: receives + integrates input from all sensory systems, higher cognitive functions
25
5 processes in development of neurons:
1) production of neurons + glia from stem cells
2) neurons move toward heir eventual destinations in brain
3) growth of axon + then dendrites
4) myelination, continues for decades
5) formation of synapses, continues throughout life
26
Neurons develoment, when do they form
- Do not form after brith
- 2 exceptions: olfactory neurons + hippocampus neurons
27
Neuron death
- 50% more neurons formed than needed
- axons and targets form synapses at random
- neurons and synapse that are not activated by experience die
- use it, or lose it!!!
-experience leads to increased dendritic + axonal branching
28
Synapse rearrangement
- rearrangement of synapses = result of cell death + activity of incoming axons
-Result of rearrangement = synaptic contacts of each axon become more focused
-experience leads to synaptogenisis + rearrangement of synapse
29
Mechanisms of recovery from damage
1. Regrowth of axons - only occurs in PNS (axons in CVS cannot regrow- damage= permanent)
2. Sprouting- formulation of new axons branch in response to loss of axons
3. Denervation Supersensitivity — increased sensitivity of neuron to remaining NT
4. Reorganisation of sensory representations — can happen when body part lost by amputataion— synaptic sites at several levels of CNS left vacant— axons representing another body part sprout into those sites— leads to phantom limb
30
What does brain damage recovers depend on
Learned adjustments in behaviour
- patients have to learn to better use abilities that have been spared
