Nervous system Flashcards
- Complete the following:
The nervous system is a ________________ of fibres which span the body co-ordinating a diverse range and voluntary and ________________ actions. It transmits ________________ between parts of the body. It responds rapidly to changes within the internal and external ________________ It works alongside the ________________ system to maintain ________________.
- A network of fibres which span the body, co-ordinating a diverse range of voluntary and involuntary actions.
- Transmits signals between parts of the body.
- Rapidly responds to changes within the internal and external environment.
- Works alongside the endocrine system to maintain homeostasis.
- Describe the difference between the central nervous system and the peripheral nervous system.
- CNS: brain and spinal cord / PNS: Peripheral nerves (nerves not in the CNS)
- With regards to neuron function, complete the following table:
Processes sensory information, analyses, stores and makes decisions:
Detects internal and external environmental changes:
Produces a response to sensory information to effect change:
Function:
Processes sensory information….: INTEGRATION
Detects internal and external environmental changes: SENSORY
Produces a response to sensory information to effect change: MOTOR
- Complete the following diagram
With regards to the effects of the sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS), complete the following table:
Explain how the enteric nervous system is linked to the CNS.
it’s linked by the sympathetic and parasympathetic nerve fibres :vagus nerve
Describe the role of the following in the enteric nervous system:
a. Sensory neurons
b. Motor neurons
c. Interneurons
a. Sensory neurons monitor chemical changes (via chemo -receptors) in the GI tract and stretching (stretch receptors) of its walls.
b. Motor neurons govern motility and secretions of the GIT and associated glands.
c. Interneurons connect the two plexus
- Draw and label a neuron:
a. Axon
b. Dendrites
c. Cell body
d. Nodes of Ranvier
e. Myelin sheath
f. Terminal endings
Define the following terms:
- Action potential
- Nerve stimulus
- Nuclei
- Ganglia
- Tracts
- Action potential: ability to create a nerve impulse
- Nerve stimulus: anything able to generate an action potential (ext/internal)
- Nuclei: collection of cells bodies forming structural & functional groups in CNS
- Ganglia: same as Nuclei but in PNS
- Tracts: axon bundles in CNS
State which vitamin is required as a co-factor in myelin production?
vitamin B12
Describe THREE key differences between ‘neurons’ and ‘neuroglial cells/ glial cells’
- Glial cells are smaller
- Glial cells 50x more prevalent
- glial cells can multiply & divide
Name the neuroglial cell that:
- Contributes to the blood brain barrier
- Is phagocytic and is mobile in the brain
- Provides structural support in PNS ganglia
- Astrocytes
- Microglia
- Satellite cells
Name the neuroglial cell that:
- Myelinates axons in the CNS
- Produces cerebrospinal fluid
- Produce myelin in the PNS
- Oligodendrocytes
- Ependymal cells
- Schwann cells
Complete the following:
Neurons at rest process an _____________ gradient across the cell membrane. This is created by the build-up of ________________ ions on the inside of the cell membrane relative to the extracellular fluid which contains more ___________ ions The separation of charges create ________________ energy. The resting potential is approximately_________ mV. Cells exhibiting a membrane potential are said to be ________________ or charged.
Neurons at rest possess an electrochemical gradient across the cell membrane. The resting potential is created by a build up of negative ions on the inside of the cell membrane, relative to the extracellular fluid which contains more positive ions.
The separation of charges across a cell membrane creates potential energy.
This resting potential is approximately -70mV. Cells exhibiting a membrane potential are said to be polarised or ‘charged’
Describe in detail the resting potential (think sodium, chloride, potassium, proteins and the sodium-potassium pump).
Resting potential is created by the build up of negative ions inside cell membrane and positive ions outside: to ensure we have more sodium outside of the axion and potassium inside we use a sodium-potassium pump = the pump move 3 sodium molecules out for 2 potassium into. It requires energy ATP as it is an active process
Describe in detail all steps in the following processes:
- Depolarisation
- Repolarisation
- Depolarisation: going from -70mV to +30mV: sodium go into the axion
- Repolarisation: +30mM to -70mV - Potassium moves out of axion
Explain what is meant by the:
- Refractory period
- Absolute refractory period
- Relative refractory period
- Refractory period: period after repolarisation where sodium & potassium are on the wrong side of membrane= nerve can’t generate any action potential.
- Absolute refractory period: even a strong impulse can’t generate any action
- Relative refractory period: need a bigger stimulus than normal to generate action
Describe in detail how the ‘synapse’ transmits a signal
synapse connects neurons: connects action potential of the axion to neurons terminal endings (synaptic end bulb) that communicate with another neuron. the neurotransmitters diffuse across the synapse and bind to receptors = open the ion channels: generating action potential
Explain TWO differences between ‘excitatory’ and ‘inhibitory’ transmitters
- Excitatory: depolarisation / inhibitory: hyperpolarisation
- Excitatory: become more positive / inhibitory: more negative
- Name the amino acid precursor of glutamate
- what are glutamate & GABA compared to glutamine
- Glutamine
- neurotransmitters
Name ONE vitamin needed for conversion of glutamate to GABA
B6
- State the location in the brain where most dopamine is stored
- where is most serotonin found
- Substantia negra
- gastrointestinal tract
In a synapse, name the ion that directly causes the exocytosis of synaptic vesicles
calcium
- List TWO functions of dopamine
- List 2 functions of serotonin
- Movement, reward mechanism
- GIT peristalsis, sleep, mood, pain regulation
List ONE neuropeptide that enhances pain
Substance P
What is the charge present in a resting membrane?
-70mV
what is meant by the action potential “Threshold”?
it is - 55mV: it is the minimum the stimulus need to reach to generate action potential
Explain what is meant by synapse
junction between 2 neurons/ neuron & muscle
- State TWO ways in which the following central nervous system components are protected:
a. Spinal cord
b. Brain
a. Spinal cord: vertebral column & meninges
b. Brain: craniumcranial meninges, cerebrospinal fluid (CSF) and the
blood brain barrier (BBB).
- With regards to the layers of the meninges, compare functions of the:
a. Dura mater
b. Arachnoid mater
c. Pia mater
a. Dura mater: strong layer, tough. Venous sinuses= blood drain into jugular veins
b. Arachnoid mater: collagen & elastic fibre
c. Pia mater: delicate layer, blood vessels supply spinal cord
Name the spaces between:
a. Dura mater and arachnoid mater
b. Arachnoid mater and pia mater
a. subdural space
b. subarachnoid space
Describe TWO key differences between ‘subdural hematoma’ and ‘subarachnoid hemorrhage’
- subdural haematoma slowly develop because venous and subarachnoid is rapid as it’s arterial bleed
- subdural haematoma must like develop in elderly people with condition like Alzheimer whereas subarachnoid: aneurysm/ berry aneurysm
List FOUR functions of CSF.
- protection of brain & spinal cord , shock absorber
- Maintain uniform pressure around the brain
- Moist of brain & spinal cord
- Circulation of nutrients & waste
- Optimal chemical environment (ion) for nerve signaling
Describe the main role of the blood brain barrier (BBB).
Protects the brain from toxins, bacteria’s & harmful substances that enter the bloodstream
Name the 2 arterial systems to supply blood to brain
Vertebral & Carotid
Name the neuroglial cell that maintains the BBB.
Astrocytes
List FOUR major parts of the brain
- Brain stem
- Diencephalon
- Cerebrum
- Cerebellum (little brain)
Name the main functions of Brainstem:
- Medulla oblongata
- Pons
- Midbrain
- Medulla oblongata: regulate heartbeat & breathing, reflexes (snoozing, vomiting &hiccupping
- Pons: help control breathing and relay motor tracts
- Midbrain: Dopamine function : movement + eye reflex and tracking, mvt head & neck
Name the area of the brain that contains the ‘pineal gland’ and what it secretes?
Epithalamus and the pineal gland secretes melatonin
List TWO functions of the cerebellum
- Maintenance of posture and balance.
- Smoothing complex mvts/ Coordination of movements.
- Correction of errors during on going movement: • E .g. learning to walk, learning an instrument.
- Cognition, thought and language processing.
- Motor behavior by altering circuits that influence motor pathways (corticospinal tracts).
List THREE factors that can damage the cerebellum.
- Chronic alcohol abuse
- Coeliac disease or a thiamine (vitamin B1)
- Cerebellar disease ‘Ataxia’: lack of muscle co ordination. Commonly results in stumbling, unsteadiness, slurred speech and an intention tremor (e.g. hand tremor when putting key in door).
Name ONE function of the Cerebrum
- Sensory perception.
- Motor control of skeletal muscles (movement).
Name the area that connects the two cerebral hemispheres
Corpus callosum
Name which cerebral lobe plays a role in:
- Hearing
- Vision
- Motor skills
- Sensory input
- Hearing: Temporal lobe
- Vision: Occipital lobe
- Motor skills: Frontal lobe
- Sensory input: Parietal lobe
Name THREE main structures within the limbic system.
- Hypothalamus
- Hippocampus
- Amygdala
Name the area that plays a key role in emotions within the limbic system.
Amygdala
Explain what could happen if there is damage to any of the spinal cords
neurological symptoms
Name the main functions of Brainstem:
- Thalamus
- Hypothalamus
- Epithalamus
- Thalamus: core of the brain as 80% of diencephalon. Major relay centre for sensory info (receive & distribute info)
- Hypothalamus: regulation & homeostasis of hormones + control ANS / body temperature + appetite/satiety
- Epithalamus: connect limbic system to others+ circadian rhythm: melatonin production
Name the 3 layers of Meninges
Dura mater/ Arachnoid mater/ Pia mater
State what is found in the subarachnoid space
Cerebrospinal fluid (CSF)
