2. Functional Neuroanatomy & Neurophysiology Flashcards
The brain is suspended in what?
Cerebrospinal fluid (CSF)
The brain is the centre of…
Cognition, emotion, behaviour and consciousness
Santiago Ramon y Cajal was a Spanish anatomist who studied what?
The structure of the nervous system by going through slices of the brain tissues to create a picture of neurons and what they look like
Outline the neurone ‘doctrine’
Neurons…
- Are the basic unit of the NS
- Are distinct and separate from each other (they are not interconnected)
- Have cells bodies, axons and dendrites
- Transmit information (in one direction only)
What are the 4 ways in which the neuron receives and processes signals?
- Collects information
- Integrates information
- Conducts information
- Outputs information
What are the 3 ways in which we know that neurons connect to other neurons?
- Can stimulate other neurons
- Can inhibit other neurons
- Can send output to many neurons
What do dendrites do & what zone are they referred to?
They seek information from other neurons and are considered the input zone
Cell body acts as which zone?
The integration zone
Information travels down the axon to the axon terminals where….
A synapse will connect the axon terminals to another neuron
What are the 2 main cells in the NS?
Neurons and Glia
Describe features of Neurons and Glia
The ‘building blocks’ of the nervous system
Small
Low contrast under a microscope
Which cell is the main cell of the NS and which has a more supportive role?
Neurons = main Glia = supportive
Neurons can connect to make __, __, or __
Circuits, chains or networks
Give an example of a circuit, chain and network
Circuit - simple reface arc
Chains - retina
Networks - convergence and divergence
Where are networks present?
In the cortex
The function of a neural circuit depends on…
- How the neurons are connected
- How strong the connections are
- Whether the synapses are excitatory (EPSP) or inhibitory (IPSP)
What is critical between excitatory and inhibitory synapses?
Balance
What do Glia cells not take part in?
The signalling or processing
What is the main function of glia cells?
To sustain the neurons by ensuring that nutrients are supplied to the neurons
What are the 2 functions that glia cells are through to have?
Protective function and metabolic function
What are the 4 types of glia?
Astrocytes
Oligodendrocytes
Schwann cells
Microglia
Astrocytes attach to blood vessels and neurons to provide…
Physical support as well as blood and oxygen
How do astrocytes ensure that each neuron gets enough oxygen?
By detecting how active neurons are and providing the sufficient nutrients required
What is the function of astrocytes in terms of synapses?
They keep them separate and clean up any debris
What is the main function of oligodendrocytes?
To support and insulate axons which speeds up neurotransmission (the myelin sheath)
Oligodendrocytes latch around the axon and excels their membrane around it multiple times to serve as…
An electrical insulation - myelination
Oligodendrocytes are only found where?
The CNS
What is multiple sclerosis?
A demyelinating disease which causes issues with motor and cognitive functions
Describe the 3 main functions of microglia and which disease they may be responsible for
- Precursors of blood cells
- Part of the brain’s immune system
- Related to macrophages (eats up debris_
May be responsible for Alzheimers
The CNS is made up of what?
The brain and spinal cord
The PNS (Peripheral nervous system) is made up of what?
All nerves and neurons that reside outside, or extend beyond the CNS
What is a nerve?
An enclosed bundle of axons
Why is there great interest in medicine in the PNS?
Because lots of diseases can cause issues in the PNS
What are the structural subdivisions in the PNS?
Cranial nerves
Spinal nerves
How many pairs of cranial nerves are there?
12
How many pairs of spinal nerves are there?
31
What are the functional subdivisions of the PNS?
Somatic nervous system and the automatic nervous system
What is the somatic nervous system?
The part of the NS that regulates emotion and conscious sensations
What is the autonomic nervous system?
The unconscious part which keeps your body working
What are the two aspects of the ANS?
Sympathetic NS
Parasympathetic NS
What are cranial nerves really important for?
Our perceptions
All our main senses are connected via them
Spinal nerves connect through…
‘Branches’ which are known as roots
Outline the different pairs of spinal nerves
8 cervical nerve pairs, 12 thoracic nerve pairs, 5 lumbar nerve pairs, 5 sacral nerve pairs, 1 coccygeal nerve pair
Each nerve has a ___ root (2 different types)
Ventral root and Dorsal root
What does the ventral root contain?
Efferent fibres (projecting away from the CNS - come from the brain back to the spinal cord)
What does the dorsal root contain?
Afferent fibres (projecting towards the CNS - come from the spinal cord to the brain)
What does the sympathetic nervous system do?
Prepares the body for action - fight/flight response
What does the parasympathetic nervous system do?
Generally helps the body to relax, recuperate and prepare for future action
The CNS is the ___ part of the nervous system
Largest
What is the CNS cushioned by and protected by?
Cushioned by fluid and protected by bone
What are the membranes that cover the CNS called?
Meninges
What are the 3 meninges?
Pia mater - soft matter
Arachnoid mater - spider-like
Dura mater - hard matter
What is the purpose of cerebrospinal fluid (CSF)?
For protection and nutrition
The CSF is critical for…
Survival to protect the NS
The CSF helps prevent the brain from…
Moving around too much and becoming physically damaged
CSF also fills what in the brain?
Large ventricles
What are the two types of matter in the brain?
Grey and white matter
What is grey matter and where is it found?
The cells bodies of neurons - found on the cerebral cortex or in concentrated areas of cell body nuclei
What is white matter and where is it found?
The axons of neurons - found on the outside of the spinal cord
Define lateral
To the side
Define medial
To the middle
Define Ipsi
Same
Define contra
Opposite
Define Ipsilateral
On the same side
Define contralateral
On the opposite side
Define bilateral
On both sides
Define superior
To the top
Define inferior
To the bottom
Define anterior
To the front
Define posterior
To the back
Define dorsal
Towards the backbone
Define ventral
Towards the stomach
Define rostral
Towards the snout
Define caudal
Towards the tail
What are the 3 slices?
Coronal, Sagittal and Horizontal
What are the 4 parts of the CNS?
Spinal cord, brainstem, diencephalon and the forebrain
What makes up the brainstem?
Hindbrain, mesencephalon - cerebellum
What makes up the diencephalon?
The thalamus and hypothalamus
What makes up the forebrain
The isocortex, basal ganglia and the limbic system
What is the main function of the spinal cord?
Connects the brain and body
What does the spinal cord house?
Local reface pathways
Damage to the brainstem is usually…
Fatal
What is the Medulla Oblongata?
The extended marrow
What does the midbrain provide?
Important info for the eyes and ears
The pons is involved in controlling what?
Nerves
What vital body functions does the brainstem control?
Breathing, heartbeat, artery dilation, salivation and vomiting
What is the pons closely connected to and what is it important for?
Connected to the cerebellum - important for movement and balance
The midbrain contains important…
Sensory and motor centres
Where does the cerebellum sit?
On top of the brainstem
What does the cerebellum do once the brain has sent ‘copies’ of commands to the cerebellum?
Compels the predicted response to what it actually receives and will make corrections
The cerebellum coordinates movements such as…
Balance, motor planning, motor learning and eye movement control
Outline the 5 features of the thalamus
- Complete cluster of nuclei
- Connected to almost any area of the cortex
- Most important relay station for outputs and inputs to the cortex
- Involved in regulating sleep
- Decides what needs to be sent to the cortex
What are the 3 main features of the hypothalamus
- A cluster of numerous nuclei
- Regulates homeostasis, metabolic processes, autonomic activities
- Links the nervous and endocrine system via pituitary gland
What does the pituitary gland do?
Releases reproductive, sex and growth hormones into the bloodstream via the hypothalamus
What is the basal ganglia comprised of?
The caudate nucleus, putamen, globus pallid us and substantiated nigra
What is the basal ganglia important for?
Motor control
What is the limbic system involved in?
Emotion, motivation and emotional memory
The hippocampus (in the limbic system) is essential for the formation of what?
Memories
What does the olfactory bulb mediate?
The sense of smell
What is the largest part of the human brain?
The cerebrum
The cerebrum consists of how many cerebral hemispheres and what are these connected by?
2 which are connected by the corpus callosum
What characterises the cerebral cortex?
Layers
How thick is the cerebral cortex?
2-4mm
The type of cortex in the cerebrum is called what?
The isocortex or also the neocortex
How many layers of cells does the isocortex have?
6
The allocortex has less than _ layers
6
The cerebral cortex forms a single deeply folded surface which allows for what?
A larger surface area (about 1 square meters)
Define gyrus (pl. gyri)
A ridge in the cerebral cortex
Define sulcus (pl. sulci)
A groove
The surface of the cerebral cortex is organised into what type of areas?
Cortical areas
Each cortical area is defined by having a unique combination of how many criteria?
3 (or 4)
What are the specific criteria for each cortical area?
- Physiology (function)
- Architecture (anatomy)
- Connectivity (connections)
- (Topography (maps))
How many lobes are there in the brain?
4
What are the 4 lobes?
- Frontal
- Parietal
- Temporal
- Occipital
Which is the smallest of the 4 lobes?
the Occipital lobe
What is the occipital lobe exclusively concerned with?
Visual processing
What separates the occipital lobe and the parietal love?
The parietal-occipital sulcus
Which is the most active lobe?
The occipital lobe
What separates the parietal lobe from the frontal lobe?
The central sulcus
What is the parietal lobe important for?
- Somatosensory perception
- Intersensory integration
- Spatial vision
- Spatial attention
Give an example of somatosensory perception
Touch
What is intersensory integration from the parietal lobe?
Integrates different information from our sense
If the parietal is lesioned, what can this lead to?
Visual neglect (such as, Gerstmann’s syndrome & Balint’s syndrome)
What separates the temporal lobe from the frontal lobe?
The Sylvian fissure
Where is the sense of hearing mediated?
The superior temporal gyrus (A1)
What separates the parietal lobe from the frontal lobe?
By the central sulcus
What is the largest lobe?
The frontal love
What are the 4 main functions of the Frontal lobe?
- Movement
- Impulse control
- Decision making
- Planning & executing behaviour
