Systems Level Neural Architecture 08.02.23 Flashcards
What can the PNS be split into?
Autonomic and somatic
What is the somatic PNS responsible for?
It interacts with the external environment
- signals come from places like the skin, muscles, joints, eyes, ears etc…
What does the autonomic nervous system control?
This regulates the body’s internal environment and it is the automatic control
Comes from internal organs to the CNS
What are the four regions of the spinal cord?
- Cervical nerve region
- Thoracic nerve region
- Lumbar nerve region
- Sacral nerve region
What constitutes the cervical nerve region?
- head and neck
- diaphragm
- arms and hands
What constitutes the thoracic nerve region?
Chest muscles
Breathing
Abdominal muscles
What does the lumbar nerve region control?
Legs and feet
What does the sacral nerve region control?
Bowel and bladder control
Sexual functions
What nerve function affects the dorsal root?
The afferent which is affected by the world and controls the sensory
What nerves are involved with the ventral root?
The efferent which has an effect on the world and controls our motor function
What does the medulla contain?
Contains tracts carrying signals between the rest of the brain and the body
What is the function of the medulla?
- autonomic control (cardiac, circulatory etc…)
- contains the caudal part of the reticular formation
- low level sensorimotor control e.g. balance
- sleep/ wakefulness
- movement, maintenance of muscle tone
What does the pons contain ?
Millions of neuronal fibres which relay from the cortex and midbrain to the cerebellum
- good for pattern generators (walking)
What is the structure and contents of the cerebellum?
- Smaller than the brain but contains as many neurons as all the rest of the CNS
- it adjusts for motor errors between intended movement and actual movement. Does this by adjusting synaptic weights to eliminate error
What is the function of the cerebellum?
- was once thought just for motor learning
- now more widely recognised for cognitive and affective/ emotional function
What are the two structures within the midbrain?
Tegmentum and Tectum
What is the function of the tectum and it’s two counter parts?
Visual/ spatial and auditory frequency maps
Two counter parts:
1. Superior colliculus (sensitive to sensory change - orienting/defensive movements)
2. Inferior colliculus (similar but for auditory events)
What are the three colourful structures of the tegmentum?
- The Periaqueductal gray
- Red nucleus
- Substantia nigra
What is the role of the Periaqueductal gray?
- defensive behaviour
- pain (ascending and descending signals)
- reproduction
What is the role of the red nucleus?
- target of cortex and cerebellum projects to the spinal cord
- pre-cortical motor control (especially arms and legs)
What is the role of the substantia nigra?
- part of the basal ganglia
- has dopamine cells
- the SN pars compacta is the basal ganglia input
- the SN pars reticulate is the basal ganglia output
What makes up the diencephalon?
The thalamus and hypothalamus
What is the thalamus role and how is it adapted for this ?
- specific nuclei: rely signals to cortex system for all sensations (but smell)
- non specific nuclei: regulate state of sleep and wakefulness and arousal
- important relays from basal ganglia and cerebellum back to cortex
What is the role of the hypothalamus?
- regulates the pituitary gland which regulates hormonal secretion: interface between brain and hormones
- so role in hormonal control of motivated behaviour
- including hunger, thirst, temp, pain, sex
What are the subcortical (under the cortex) portions of huge forebrain?
Basal ganglia
Limbic system
What is the structure of the basal ganglia?
Group of structures
Loop organisation
What is the role of the basal ganglia?
Motor function and reinforcement learning
What is the role of the limbic system?
Group of structures involved in emotion, motivation and emotional association with memory
- it influences the formation of memory with stored memories and physical sensations
What structures are within the limbic system?
- Amygdala
- Hippocampus
- Fornix
- Cingulate gurus
- Septum
- Mammillary body
What is the role of the Amygdla?
Associating sensory stimuli with emotional impact
What is the role of the Hippocampus?
Memory (long term) and spatial memory
What is the role of the cingulate gyrus?
Linking behavioural outcomes to motivation and autonomic control ( increased in schizophrenia)
What is the role of the mammillary body?
Recollective memory (amnesia)
What is the role of the septum?
Defence and aggression
What is the role of the fornix?
Bundle of fibres that carries signals from hippocampus to mammillary bodies and septal nucleus
What does the frontal lobe contain?
Pre central gyrus from which motor instructions are sent to muscles controlling hands and feet
What is the function of the frontal lobe?
Primary motor cortex (voluntary movements)
Premotor and supplementary motor areas
What structure does the parietal lobe contain?
Contains post central gyrus which received sensation from the rest of the body
What cortex is in the parietal lobe?
The primary somatosensory cortex
- allows us to know where our body and heads position is in space
What cortex is in the temporal lobe ?
Primary auditory cortex
Infero temporal cortex (recognition of faces and objects)
What is the role of the occipital lobe?
Vision for movement and identification
