Anatomy Practical 2 Flashcards
What is the limbic system?
Group of structures
On the medial aspect of the cerebral hemisphere and diencephalon
Encircles upper brainstem
Emotional/affective brain
Which parts of the limbic system are important in emotions?
Amygdale
Anterior cingulated gyrus
What does the amygdale do?
Recognises angry and fearful facial expressions
Assesses anger
Elicits fear response
What does the cingulated gyrus do?
Expresses our emotions through gestures
Resolves mental conflicts when we are frustrated
What makes up the basal ganglia?
Caudate nucleus
Putamen
Globus pallidus
What does the diencephalon consist of?
Thalamus
Hypothalamus
Epithalamus (pineal gland)
- all enclose the 3rd ventricle
What does the cingulate cortex do?
Memory storage
What does the hippocampus do?
Formation of memroy
What is the function of the fornix?
Pathway from hippocampus to storage (cingulate cortex)
What is the function of the parahippocampal gyrus?
Storage of memory
What is the significance of the connections between the cortex and the limbic system?
- intimate relationship between our feelings and thoughts
- react emotionally to things we consciously understand
- explains why emotions sometimes override logic and why reasons can stop us from expressing emotions
How are smells linked to emotions?
Connections between olfactory bulb and amygdale (emotions) as well as the hippocampus (associative learning)
Which parts of the cerebellum have what sensory and motor maps?
Anterior and posterior lobes overlap
- medial portions influence motor activities of trunk
- intermediate parts concerned with distal limbs in skilled movements
- flocculonodular lobe receives input form inner ear to adjust posture and balance
How does cerebellar processing for motor activity occur?
- motor areas of the cortex notify cerebellum to initiate voluntary muscle contraction
- cerebellum receives info from proprioceptors of body so cerebellum can evaluate body position and momentum
- cerebellum calculates best way to co-ordinate force, direction and extend muscle contraction preventing overshoot/maintain posture/ensure smooth co-ordinated movement
- superior peduncles (output) allows cerebellum to dispatch info to cerebral motor cortex to co-ordinate movement, cerebellum also sends fibres to neurons in the brainstem influencing motor neurons in cord
What does the diencephalon consist of?
Thalamus, hypothalamus and the epithalamus (pineal gland)
All close the 3rd ventricle
What are the features of the thalamus?
- bilateral egg shaped masses
- connected ta midline by interthalamic adhesion
- contains nuclei which project to or receive fibres from cerebral cortex
- afferents converge there and synapse with nuclei
- information gets sorted and edited
What is the function of the thalamus?
- key role in mediating sensation, motor activities, cortical arousal, learning, memory
- gateway to the cerebral cortex (consciousness)
What is the function of the hypothalamus?
Below the thalamus Contains nuclei Small size Main visceral control centre of the body Body homeostasis
What is the function of the epithalamus?
pineal gland which secretes melatonin
together with hypothalamus melatonin regulates sleep and wake cycle
What is the purpose of the CSF?
cerebrospinal fluid
cushioning
buoyancy
reduces brain weight by 97% preventing brain from crushing under its own weight
protects brain and spinal cord from blows and other trauma
helps nourish the brain
carries chemical signals from one part of the brain to another
What is the composition of the CSF?
similar to blood plasma
formed from blood plasma
fewer proteins
different ion concentrations
What is hydrocephaly?
CSF circulation/drainage obstructed so accumulates and exerts pressure on brain
- new born babies = head enlarges as skull bones not fused but in adults occurs more rapidly as skull is rigid so fluid accumulates and compresses blood vessels serving the brain and crushes soft nervous tissue
