Neurology Flashcards
General functions of the nervous system (5 in total) (MISCT)
Sensory
Communicative
Integrative
Motor
To respond to both internal and external stimuli
What two systems make up the nervous system?
Central nervous system - brain and spinal cord
Peripheral nervous system - nerve fibers
How many pairs of cranial nerves are there?
What are the different types of cranial nerves? (Not identify, just mention the category of nerve)
12 pairs. Sensory/Motor nerves, or both
How many pairs of spinal nerves are there? How many per section of the spines?
Certain important features regarding the spinal nerves (Just open to view if you dk)
Slide 7 of Neuro 1
31
8 Cervical
12 Thoracic
5 Lumbar
5 Sacral
1 Coccygeal
Other things to note:
- C8 nerve is squeezed in-between C7 and T1, thus all nerves from T1 onwards are all originating from its’ respective vertebral
- Spinal cord ends at ~L1, corresponding nerves just compress and continue downwards from the end of spinal cord and out its’ respective vertebrals
Which 2 divisions make up the Peripheral Nervous System (PNS)
Afferent division
Efferent division
Definite the purpose of both Afferent and Efferent divisions in the PNS
Afferent - A for Away, transmit information to the CNS, primarily sensory stimuli and visceral stimuli
Efferent - E for Exit, transmit information from the CNS to effector organs
Further division of the Efferent Nervous system
Somatic Nervous System
Autonomic Nervous System
Definite Somatic Nervous System and Autonomic Nervous System
SNS
- Made of fibers of the motor neurons that supply the skeletal muscle
- Voluntary control
ANS
- Sympathetic and Parasympathetic nervous system
- Made of fibers that innervate the smooth muscles, cardiac muscles and glands
- Involuntary control
Page 10 and 11 of Neuro 1 has a good summary of the types of nervous systems and their components, as well as the organisation of the nervous system. Good to view!
GO SEE, i want to drop out alr (this is a cry for help)
Two types of neurons that make up the autonomic nerve pathway
Preganglionic neuron
Postganglionic neuron
What is the difference between both neurons in the autonomic nerve pathway
Preganglionic neuron - synapses with the postganglionic fiber’s cell body via the ganglion
Postganglionic neuron - sends axon to the effector organs
Where are preganglionic neurons located based on spinal level
T1 to L2
What is used to describe the sympathetic chain ganglia?
Beads on a chain structure (Page 14 of Neuro 1)
What is special about the preganglionic length on sympathetic innervation
There is a shorter preganglionic, and a longer postganglionic
What is special regarding the preganglionic fiber’s synapse ability
It can synapse with 1 or more ganglionic neurons, this network ensures whole SNS is activated, allowing activity to be sent out fast across the chain (Generalised sympathetic response)
What is special about the preganglionic length on parasympathetic innervation
Long preganglionic, short postganglionic
What organ regions does the parasympathetic division innervate
What nerve supplies majority of the output
Cranial, Trunk, Pelvic
Vagus nerve supplies ~75% of the output
Effects of ANS on various organs
Page 16 of Neuro 1
Tip: Memorise it based on Parasympathetic as Resting and
Relaxing, and sympathetic as Fight or Flight
What makes up the CNS
Brain
Spinal cord
Grey matter
White matter
What is Grey and White matter
Grey matter - generic term for collection of soma in the CNS (The nucleus with all the tree branches thing)
White matter - generic term for collection of CNS axons (The long body)
What is in place to protect the CNS from injury
Cranium and vertebral column
Meninges
Cerebrospinal fluid
Blood-brain barrier
Describe the Mininges’ purpose and layers
3 membranes
- Wrap, Protect, Nourish
- Pia mater, Arachnoid mater, Dura mater (Inside to outside)
What is present between the Pia mater and Arachnoid mater? What is it filled with
Subarachnoid space, filled with cerebrospinal fluid
Describe the cerebrospinal fluid
Shock absorbing fluid
Surrounds and cushions the brain and spinal cord
Transport nutrients, chemical messengers, waste products
How is the cerebrospinal fluid formed?
Via the choroid plexuses in brain’s ventricles
How many ventricles are there in the brain?
4, all connected together
What is the pathway for the CSF within the brain?
- Produced by the ependymal cells of the choroid plexus
- Circulate throughout the ventricles
- Exits the 4th ventricle
- Flows in subarachnoid space
- Reabsorbs into venous blood
Purpose of a lumbar puncture?
Collection of fluid from within the subarachnoid space to identify any infections/tumors within the CNS
Composition and purpose of the blood-brain barrier (BBB)
Formed by networks of tight junctions
Isolates CNS neural tissue from general circulation
Regulates exchange between blood and brain
- CSF and blood chemical composition can differ
- Selectively isolate brain from chemicals in blood that might disrupt neural function
Nourishment of the CNS
- constant need of oxygen and glucose via blood
- does not store any glucose, only utilises it
- cannot produce ATP without oxygen
- 13%-15% Cardiac output (High % despite relatively small muscle)
General function of the CNS (VEEPS)
Voluntarily control movement
Engage in other higher cognitive processes
Experiences emotions
Perception of body and surroundings
Subconsciously regulates homeostatic responses
Components of the brain
(BCF, DHT, CCB)
Brain Stem
Cerebellum
Forebrain
1. Diencephalon
- hypothalamus
- thalamus
2. Cerebrum
- Cerebral cortex
- Basal nuclei
Structures of the brain
Cerebral cortex, Basal nuclei, Thalamus, Hypothalamus, Cerebellum, Brain stem
Function of Cerebral cortex (SMPH)
Sensations
Movements
Personality
Higher order functions
Function of Basal nuclei
Control of movement
Function of Thalamus
Relays most of the sensory input
Function of Hypothalamus
Homeostatic functions
Function of Cerebellum
Control movements
Balance
Function of Brain stem
Vital physiological functions
Centre of control
4 lobes of the cerebral cortex, and what two structures separates what from each other
Frontal lobe
Parietal lobe
Occipital lobe
Temporal lobe
Central sulcus, separates frontal and parietal lobe (Front and back)
Lateral fissue, separates frontal & parietal from temporal lobe (Up and down)
What is dermatomes
Area of skin that is supplied by a single spinal cord level
OR
One side of the skin by a single spinal nerve
What is myotomes
Portion of a skeletal muscle that is innervated by a single spinal cord level
- usually innervated by nerves from >1 spinal cord level
Spinal Nerves T1-L2 operate using two types of roots. What are the two roots and what passes through it?
Dorsal and Ventral root
Dorsal - Sensory signals, Ventral - Motor signals
What are the two ramus and what do they contain and what do they supply?
Posterior ramus - Both sensory and motor, supplies to posterior part of the body (skin and skeletal muscles of the back)
Anterior ramus - both sensory and motor, supplies to anterior part of the body (body wall, limbs etc)
Describe nerve plexuses
Either somatic or visceral
Combination of fibers from different sources or levels to form new nerves with specific targets
Damage to a single spinal nerve is less likely to result in paralysis
2 examples of autonomic plexuses
Cardiac plexus
Pulmonary plexus
