Chapter 1 Overview of CNS Flashcards
What are the divisions of the Nervous System
Central and Peripheral
What are the divisions of the PNS?
Somatic + Autonomic
What is the role of Somatic nervous system and autonomic nervous system?
Somatic - voluntary control. Autonomic is Involuntary control( the sense and motor nerves innervate glands and visceral organs)
What are the subtypes of the Autonomic nervous system ?
Sympathetic and Parasympathetic
What is the function of Sympathetic and parasympathetic system?
Sympathetic - prepares the body for fight, flight or fear - by activating glands and visceral organs to spend body energy . Parasympathetic body - brings the body back to homeostasis or normal post the activation of the Sympathetic system - conserves the energy.
- What is the smallest functional unit of the brain?
Neuron
What are the 3 main elements of a neuron?
cell body, dendrites, axon
What does cell body contain?
- Cell body or soma containing nucleus and main organelles
Dendrites function?
Receive info from other neurons or cells
Axon parts?
Axon hillock + Axon initial segment
Where is the action potential generated?
Axon hillock + Axon initial segment
What is the location pf Axon hillock location ?
The last part of the cell body
Which is the most electrically
excitable part of the neuron?
Axon initial segment
What is myelination?
Fatty lipid from glial cells that surrounds and insulates the axon, allows for rapid conduction of Action potential
Action potential is rapidly conducted in an unmyelinated axon or myelinated axon?
Myelinated axon
What is an internode?
Portion of a nerve fiber between two Nodes of Ranvier. Formed by schwann cell
What is the Axon terminal structure called?
synapse
What is a synapse?
it is a functional unit that connects neuron to the target structure
What does terminal Bouton do?
releases neurotransmitters
What is the part between 2 communicating neurons called?
Synaptic cleft
What do glial cells provide?
Metabolic requirements and myelination
Neurons can be differentiated into two types? how ?
based on function and shape & size
What are the 4 types of neurons?
- Sensory - sensitive to various stimuli or
receive direct connections from nonneural receptor
cells. 2.motor neurons: these end directly on muscles, glands,
or other neurons in PNS ganglia - interneurons: reside solely in the CNS, interconnecting
other neurons - projection neurons: with long axons connecting, say a
neuron in the cerebral cortex and the spinal cord.
3 types of neurons based on shape / size?
Multipolar, bipolar and unipolar
Which colour are cell bodies and dendrites mostly?
Grey
Why are axons white?
Because of myelin - the fatty lipid gives it a whitish colour
What part is the basis of thought and volition( will) in the brain or CNS?
Cerebral cortex
Spinal cord + brain stem functions?
regulate autonomic functions
What is the NEURAXIS?
CNS - Brain + spinal cord form an axis through the body
Complexity of functions increases from
spinal cord to cortex. True or False?
True
3 planes of the brain
Horizontal, coronal and sagittal
4 anatomical orientation of brain
Dorsal, Caudal, Ventral, Rostral or Superior , posterior, inferior , anterior. ( clockwise order)
What is brain weight at birth?
- 400 g at birth
Brain weight doubles by 3 why?
due to the addition of myelin and growth
of neuron processes rather than the addition of neurons
11-50 brain weight?
1400g ( double - 200g)
Is there a correlation between brain size and mental ability ?
Yes, modest
What is the key difference between human brain and animals?
complex neuronal interconnection and
selective increase in the size of certain areas.
What cover the surface of the brain ?
Sulci and gyrus
What is sulcus, gyrus and fissure?
Gyrus - ridge. sulcus - groove b/w 2 ridges. Fissure - deep sulcus
3 types of control?
Contralateral, ipsilateral and decussation
What are some exceptions to contralateral control
Olfactory(smell), visceral pathways, taste
What senses have ipsilateral pathways?
Sense of smell and taste
Our somatotopic mapping is inverted? what does that mean
our foot receptors are represented at top and mouth at an inferior position
Anatomical positioning of brains stem is different from brain
Rostral– dorsal– caudal- ventral ( one shift)
Is intelligence defined by no. of neurons?
No determined by connection between those neurons
How many neuron pathways involved in somatosensory information?
3 , skin - to spinal cord - brain - brain to skin.
What is unique about the stretch reflex?
That there are only two neuron pathways involved, the reflex occurs at spinal cord level. The sensory neuron is connected to the motor neurons
