Divisions and Function of the Nervous System Flashcards
What is the nervous system? DIAGRAM
What are the two Nervous systems?
Central and Peripheral
What is the Central Nervous System ?
- Brain and spinal cord
What is the Peripheral Nervous System?
-Sensory neurons (messages from periphery to spinal cord nerves (messages from spinal cord to muscles/glands)
What is the nervous system divided into?
-SOMATIC
-AUTONOMIC
What are the building blocks of the Nervous System
- Neurons
-Oligodrebdrocytes (CNS)/ Schwann cells (PNS)
-Astrocytes
What are Neurons?
–Many have a lipid sheath called myelin
-Highly specialised cells
-Responsible for communication (action
potential/neurotransmission)
What is Oligodrendrocytes (CNS)/Schwannn cells (PNS)?
-Produce myelin, facilitate transmission
What are Astrocytes ? digram
-Enable homeostasis, physical
Glial cells support neurones (diagram)
What are the 3 functional types of neurons?
What are afferent or sensory neurones ?
-(sense)-signals from the periphery to CNS
What are motor neurons?
What are autonomic neurons?
What are interneurons ?
What are the 3 main function types of neurons ?
1) Peripheral nervous system - afferent or efferent neurones
2)Central nervous system -Inteneurons
3) morphological types-Unipolar, Bipolar, Multipolar
What are morphological types of Neurons?
-Unipolar
-Bipolar
-Multipolar
What are unipolar neurons?
What ate bipolar neurons?
What are multipolar neurons?
What is a nerve?
What do neurons from ?
-They form networks in order to communicate
What is the site called where one neuron meets another?
-At the Synapse
What is the synapse?
How do neurons form networks to communicate?
- Where one neuron meets another - synapse
- Electrical action potential triggers release of chemical signal (neurotransmitter)
- Neurotransmitters from the presynapse bind to postsynaptic receptors, triggering depolarisation of the postsynaptic neurone
What are neurotransmitters?
What is the Synapse ? diagram
- Very complex structure- maintains synaptic shape and function
What is a receptor?
What are the receptor types? diagram
What does an inhibitory synapse involve?
What does an excitatory synapse involve ? diagrams
What is Synaptic Transmission?
- Synaptic structures are complex
- Multiple synapses onto the same dendrite, can be excitatory or inhibitory
- Whether the neurone fires or not is a sum of all the synaptic inputs
What are inhibitory synapses? diagram
What are Excitatory synapses? diagram
What is the integration of multiple steps?
What are the types of neurotransmitters ?
-Excitatory neurotransmitters
-Inhibitory neurotransmitters
-Neuropeptides
What are examples of Excitatory neurotransmitters ?
Glutamate
-Monoamines
-Acetylcholine (mostly)
What are examples of Inhibitory neurotransmitters?
-GABA
-Glycine
-Endorphins
What are examples of Neuromodulators ?
-Neuropeptides
-Endocannabinoids
What direction does Action Potential travel through the nerve cell? DIAGRAM
The Brain and its protection- What is the Cranium ?
-This is a layer of protection of which protects the brain and the spinal cord
The Brain and its protection- What is the Meninges of the brain?
-are the membranes covering the brain and the spinal cord
What layers are present in order to protect the brain and spinal cord?
-The Cranium
-The meninges (membranes)
What is the Cerebrospinal fluid (CSF)?
- Salty solution secreted into ventricles by choroid plexus
- Consists of transporting epithelia (ependyma): ependymal cells
- From ventricles to subarachnoid space around the brain and spinal cord
- Protection
- Physical: buoyancy and padding
- Chemical: Stable ionic environment
- Different to plasma
- No blood cells little protein
Labelled Diagram of the brain?
How does blood supply around the brain?
- Internal carotid and vertebral arteries supply brain, form circle of Willis
- Smaller arteries branch off, run over surface then penetrate brain
Why does there need to be a large blood supply to the brain?
- Nervous tissue: high metabolic requirements
- Requires high rates O2 and glucose
- 15% of blood supply to brain
- Very sensitive to Ischaemia
Blood Supply to the Brain diagram?
What is the The blood brain barrier (BBB)?
-protects CNS
How does the BBB protect the CNS?
-Capillaries in the brain less permeable
– Exclude many molecules entering from the blood stream
- Protects brain from fluctuations in blood
- Endothelial cells line the capillary walls with tight junctions between them
- Processes from glial cells astrocytes form a barrier around blood vessels
- Some lipid soluble molecules can diffuse through cells
- Specific transporters allow certain molecules to access the brain
- The BBB is not complete in some brain areas
- Eg pituitary
- Vomiting centre in medulla
What is Gray Matter of the brain?
What is White Matter of the brain?
Diagram of brain?
What do bundles of axons do in the brain?
- connect different regions called tracts (often myelinated-lipid substance that covers some axons to speed up neurotransmission)
What occurs at the spinal cord?
-This is where information comes in to the CNS and directions are sent out
-Messages are sent to and from the brain
What protects the spinal cord?
-Vertebral Column
What is the Vertebral Column?
What are the 4 regions of the spinal cord?
-Cervical, Thoracic, Lumbar, Sacral
Diagram of spinal cord ?
What do the sensory nerves do in the spinal cord?
-enter via dorsal root
What do the motor nerves do in the spinal cord?
-leave via ventral root
The segments of the 4 regions of the spinal cord do what?
-Segments within these give rise to spinal nerves
What are the spinal nerves?
What is the (transverse/cross section) of the spinal cord?
-Provide distinct patterns?
Diagram of sensory nerve in and motor nerve out
What are ascending tracts in the spinal cord?
-they carry sensory information to the brain
What are descending tracts in the spinal cord?
-Carry commands to the motor neurons from the brain
Ascending and Descending tracts diagram - spinal cord?
What are axons?
-they carry information to and from the brain
Spinal cord: Peripheral nerves?
-NOT CNS
What are the two main types of Peripheral nerves? spinal cord
-spinal nerves
-cranial nerves
What are Peripheral nerves:?
-Nerves of which branch off the spinal cord
What is the Spinal nerve?
a mixed spinal nerve, which carries motor, sensory, between the spinal cord and the body.
In humans, how many Paired peripheral nerves are there? and what are they?
-31 pairs
-8 Cervical
-12 Thoracic
-5 Lumbar
Approx how many neurons does the human brain have?
-100,000,000,000
What is the function of the brain stem?
-involuntary functions, blood pressure, breathing, vomiting, sleep/arusal
Diagram of brain and labels functions such as the -Hypothalamus?
What is the Cerebrum of the brain?
What is the Hypothalamus of the brain?
What is the Corpus Callosum of the brain?
What is the Ventricles of the brain?
What is the Thalamus of the brain?
What is the mid-brain?
What is the cerebellum of the brain?
What is the brain stem?
What is the medulla of the brain?
What is the Pons of the brain?
What is the pituitary gland of the brain?
What is the Cerebrum known as?
-The cortex
What is the cortex ?
What are the 4 lobes of the cortex?
-Frontal:
-Parietal:
-Occipital:
-Temporal:
What is the -Frontal lobe of the cortex?
-Reasoning, planning, speech, movement, problem solving
What is the -Parietal lobe of the cortex?
-Movement/ orientation recognition, stimuli perception
What is the Occipital lobe of the cortex?
-Visual processing
What is the Temporal Lobe of the cortex?
-Perceptions/recognition of auditory stimuli
Diagram of where each lobe of the cortex are located?
What is the cortex?
2 hemispheres joined by corpus callosum
What are the 2 hemispheres of the cortex?
-Left Cerebral hemisphere
-Right Cerebral hemisphere
What is the corpus callosum?
Full cortex diagram?
What are the Cerebrum: Sub cortical structures ?
– Three clusters of nuclei (cell bodies)
- Basal ganglia: Control of movement
- Limbic system
- Amygdala: emotion and memory
- Hippocampus: Learning and memory (under temporal lobe)
What are the 10 Cranial nerves (PNS)?
What is most of the brain made up of?
-Gilal cells?
What are gilail cells?
Synaptic structures enable what?
-neurotransmitter release and detection
Neurotransmitters can be?
-excitatory or inhibitory
What does the sum of all synaptic inputs determine?
-The firing of neurone