Central nervous system pharmacology Flashcards
What is the role of the Relay centre?
The relay centre is found in the brainstem and passes all information from the body into the spinal cord via the brainstem.
- Is NOT passive- initial processing occurs here
What is the role of the reticular formation?
This is a network of neutrons throughout the brain stem that receives and integrates sensory input from the periphery and allows filtering out of un-necessary information. e.g. when asleep, only allows necessary info e.g. baby crying
- Also plays a role in consciousnes and awareness of what is around us
What are the sub-divisions of the brainstem?
- Medulla oblongata: important in involuntary function:
Vital reflex centre e.g. controlling of breathing, circulation, digestion
Non-vital reflex centre: e.g. cough, vomitting (is also home to the CTZ) - Midbrain: Contains the substantial viagra which is important in the control of movement - rich in dopamine neutrons (key in Parkinson’s disease)
- Pons
Discuss the role and structure of the brain stem?
Brainstem involves the medulla oblongata, pons and the midbrain.
- Has the relay centre- The relay centre is found in the brainstem and passes all information from the body into the spinal cord via the brainstem.
- Is NOT passive- initial processing occurs here
- Involves the reticular formation- This is a network of neutrons throughout the brain stem that receives and integrates sensory input from the periphery and allows filtering out of un-necessary information. e.g. when asleep, only allows necessary info e.g. baby crying
- Also plays a role in consciousnes and awareness of what is around us
- reticular activating system- involved in arousal and waking us up
- Has reflexes involved in balance and posture
- most cranial nerves exit here
- Medulla oblongata: important in involuntary function:
Vital reflex centre e.g. controlling of breathing, circulation, digestion
Non-vital reflex centre: e.g. cough, vomitting (is also home to the CTZ) - Midbrain: Contains the substantial viagra which is important in the control of movement - rich in dopamine neutrons (key in Parkinson’s disease)
- Pons- contains many nerve fibres that transmits information from one part of the brain to the other e.g. cerebrum to the cerebellum
What is the role of the cerebellum?
The cerebellum is attached to the brainstem via fibres.
The main function is the fine control of movement- coordination of voluntary movement:
- Integration of information: Sensory information from the muscles, skin, eyes, joints and ears- allows us to know the position of the body in space by input from motor areas
- Involved in planning and initiation of movement- input out to motor areas
- Procedural memory- Allows coordination of sub-conscious motor tasks e.g. knowing a dance without having to think about it
- Balance
- Eye movement
What is the Dinecephalon?
The diencephalon is divided into the thalamus and the hypothalamus:
- Thalamus: Contains the relay centre, where all sensory pathways pass through in order for preliminary processing, filtering and directing of signals to the correct area of the brain.
Involved in motor control
- Hypothalamus: Major homeostatic control centre- integrates all homeostatic inout from the body e.g. Heart rate, blood pressure, oxygen.
= regulates the Autonomic NS and endocrine system to mediate response to these homeostatic changes
e.g. changes in temperature:
- If decreased : vasoconstriction which causes shivering
- If in increased: vasodilation
- Also controls secretion of hormones by the pituitary glans
- is part of the limbic system- important one motion, memory and behavioural patterns
- role in sleep/wake cycle
Discuss the structure and function of the limbic system
The limbic system is an interconnecting group of structures in the forebrain beneath the cerebral cortices.
Includes:
Thalamus
Hypothalamus
Hippocampus
Spinal cord
Amygdala
Olfractory tube
Frontal lobe
Septal nuclei
- Is associated with basic emotions e.g. fear, anxiety, anger, pressure, satisfaction.
- mediates neural centres controlling basic behaviour in repose to these emotions e.g. preparing for attack (fear: hypothalamus controls fight or flight responses), laughing, crying.
- Role in survival- eating, drinking, sex = pleasure and satisfaction, so stimulates reward pathways to motivate us to do it again.
or punishment pathways: if action caused fear, anxiety - we know to avoid it in future. - Role in olfaction- smell- if they make us happy, we can remember it- as hypothalamus and hippocampus are both part of the limbic system
- hippocampus- role in memory
What is the role of the amygdala?
The main function of the amygdala is in emotional responses, including feelings of happiness, fear, anger, and anxiety.
This area is also key for the formation of new memories. The amygdala interacts with the hippocampus by attaching emotional content to memories.
What is the structure and function of the cerebrum?
Basal nuclei- contains grey matter which is a collection of cell bodies within the subcortical region:
- Caudate nucleus
- Globus pallidus
- Putamen
- is involved in control of movement, ‘Extrapyramidal motor system’- modulation of motor activity, usually inhibitory activity causing inhibition of muscle tone to stop contractions.
is important in purposeful vs unwanted movement - posture and support- co-ordination of sustained contractions of muscles
Discuss the structure of the cerebral cortex?
There are two hemispheres- left and right, that make up 80% of the brains weight.
- Has a thin layer of grey matter containing cell bodies, dendrites and glial cells- processing, the increased SA of grey matter means increased processing can take place.
- beneath this grey matter, is white matter- myelinated axonal tracts that take info from one part of the brain to another
- Is highly convoluted (brain curly structure) with peaks (gyri) and troughs (sulci). level of convolution is proportional to the complexity of the organism.
- Has contra-lateral control: left hemisphere controls right side of the body
- The 2 hemispheres are connected by the corpus callosum- a fibre tract made of axons that relays info between both sides of brain.
- The hemispheres are not symmetrical in structure or function e.g. language centres are just in the left hemisphere.
- Has 4 lobes: Frontal, parietal, occipital, temporal
- The function of the cerebral cortex is involvement in higher functions e.g. language, intellect, conscious thought, sensory analysis, perception, motor function. In an exam, write about each of the 4 lobes aswell!!
What is the function of the occipital lobe?
Contains the visual cortex which has primary and secondary functions.
Primary: Takes information from the retina to the brain for visual processing
Secondary: Further processing
The occipital lobe is the visual processing area of the brain. It is associated with visuospatial processing, distance and depth perception, color determination, object and face recognition, and memory formation.
What is the function of the temporal lobe?
Contains the auditory cortex: both primary and secondary.
- This part of the brain helps with processing sounds, understanding language, forming memories, and regulating emotions
- Hearing – The temporal lobes receive auditory information from the ears and help interpret sounds and words.
- Memory – the hippocampus is located in the temporal lobes. The hippocampus helps form new memories about events, facts, places, and experiences.
Language – Wernicke’s area in the left temporal lobe is important for understanding spoken and written language.
Emotion – The amygdala, found deep in the temporal lobes, regulates emotions like fear, anger, and aggression. It also links memories to emotional reactions.
What is the function of the parietal lobe?
Processing of sensory information from different areas of the body.
- Contains the primary somatic sensory cortex and association area:
- Touch – The primary somatosensory cortex receives information about touch, temperature, pain, and the body’s position.
Integration – It combines input from the senses to represent the body and its location in space.
Motion – The parietal lobes guide actions and movements in response to sensory stimuli.
Attention – It plays a role in selective attention and focusing on relevant stimuli.
Spatial orientation – This region helps construct a sensory map of the environment and understand spatial relationships.
What is the function of the frontal lobe?
Role is in motor function:
- Primary motor cortex- initiating voluntary movements
- Pre-motor area- planning
- Pre-frontal area- thinking, decision-making, personality
What is the Wernicke’s area?
Located at the back of the temporal lobe and is involved in language comprehension.
