Systems level CNS architecture NOT COMPLETE Flashcards
What stimuli cause a defense-related output?
How do they change in complexity?
Pain response (spinal cord)
Loom response (sensorimotor brain)
Learned threat (cortex + limbic system)
Each involve increasingly complex neural systems and pathways
How are more complex behaviours developed?
Built on top of original behaviours - new behaviours don’t replace old ones but are added on e.g. still have pain response
What is the peripheral nervous system divided into?
Somatic nervous system (conscious)
Autonomic nervous system (unconscious)
What are afferent and efferent nerves?
Afferent - sensory signal
Efferent - motor signal
Can be somatic or autonomic
What does the medulla do?
Contains tracts carrying signals between the rest of the brain and the body
- low level sensorimotor control e.g. balance
- involved in many vital functions… sleep/wakefulness, motor plant, various cardiac, respiratory etc reflexes
Where are the inferior and superior colliculus? What do they do?
On the tectum of the midbrain - ‘little hills’
superior - sensitive to sensory change, orienting/defensive movements
inferior - similar but for auditory events
What is in the tegmentum?
Substantia nigra
Red nucleus
The Periaqueductal gray
Where is the periaqueductal gray?
What does it do?
Midbrain, tegmentum, surrounds the cerebral aqueduct
Role in defensive behaviour
Role in pain (ascending and descending signals)
Role in reproduction
Where is the red nucleus?
What does it do?
In the midbrain, tegmentum
Target of cortex and cerebellum, projects to spinal cord
Role in pre-cortical motor control - esp arms and legs
Where is the substantia nigra in the brain?
What is its role?
Midbrain, tegmentum, from front on view, is behind the crus cerebri
Part of the basal ganglia
Substantia nigra pars reticulata - basal ganglia output
It is involved in initiating movement, inhibits inhibition of movement, ergo initiating movement
What is the thalamus? Where is it?
Specific nuclei - relay signals to cortex/limbic system for all sensations (apart from smell)
Non-specific nuclei - regulating state of sleep/wakefulness and levels of arousal
Important relays from basal ganglia and cerebellum back to cortex
In the diencephalon, forebrain
Where is the hypothalamus?
What does it do?
Diencephalon, forebrain
Regulates the pituitary gland, which regulates hormonal secretion (interface between brain and endocrine)
inc. hunger, thirst, temperature, pain, pleasure, sex
What is the forebrain made up of?
Telencephalon:
cortex
basal ganglia
limbic system
Diencephalon:
thalamus, hypothalamus etc
What is the basal ganglia
set of structures in brain that seem to be really important in regulation and coordination of motor function
Action selection - select the better action and reinforcement learning MAYBE - SHEFF RESEARCH
What is the limbic system?
Involved in emotional response, motivation, emotional association with memory
Influences formation of memory - integrating emotional response with stored memory of physical sensations
What structures make up the limbic system?
What and where is the tectum?
For visual/spatial and auditory frequency maps
Made up of the superior colliculus and the inferior colliculus
What are the two roots in the spinal cord?
Dorsal root - afferent (sensory)
Ventral root - efferent (motor)
Where is the pons?
What does it do?
In the hindbrain
Relay from the cortex and midbrain to the cerebellum - millions of neuronal fibres
Pontine reticular formation
Contains nuclei for many cranial nerves
What is the pontine reticular formation?
Region on the pons involved in sleep-wake cycle and filtering incoming stimuli
Part of the reticular formation that spans spinal cord to thalamus
Where is the cerebellum?
What is its main function?
In the hindbrain
Adjusts for ‘motor errors’ between intended movement and actual movement - eliminates error
What are the structures of the midbrain?
Tectum
Tegmentum
Cerebral peduncles
What is on the tectum of the midbrain?
Superior colliculus - preliminary processing of visual stimuli, sensitive to sensory change
Inferior colliculus - auditory
What is in the diencephalon?
Thalamus
Hypothalamus
3 other types of thalamus
