Topic 5 - Central nervous system Flashcards
(19 cards)
Where in the CNS do neurons from the PNS enter/exit?
They enter and leave the spinal cord by passing through small gaps in the vertebrae
What are the layers underneath the skull?
- They’re 3 meningeal layers
1. dura mater
2. arachnoid membrane
3. pia mater - These meninges help protect neural tissue in brain; prevents it bumping to skull when moving
- Also the cerebrospinal fluid (CSF) b/w arachnoid membrane & pia mater
*Note there’s also the blood brain barrier (BBB) for protection of CNS
Where is the CSF formed?
Choroid plexus (which is blood vessels in parts of the ventricles of the brain)
What does the BBB do?
- It isolates the CNS from potentially harmful substances in blood (like blood-borne pathogens)
- Also shelters CNS from hormonal & ion fluctuations in blood
What is the BBB composed of?
- composed of specialised endothelial cells (has no gaps b/w them thus less leaky)
- endothelial cells lining capillaries near brain have tight junctions meaning compounds (glucose, O2, CO2) have to go through cell
- astrocytes = 2nd barrier & foot processing (promote tight junction formation - p.10 D5.2)
*Note: larger molecules (bacteria) can migrate into body around epithelial cells
What are the 4 major areas of the brain?
- Cerebrum (seat of intelligence)
- Cerebellum
- Diencephalon
- Brain stem
What are the 2 surfaces of the Cerebrum?
- Gyri (thick folds - big squiggles)
- Sulci (the grooves in b/w Gyri)
What are the 2 major subdivisions of the cerebrum?
- Cerebral cortex (has 4 lobes)
- Various subcortical regions (e.g basal nuclei - motor functions)
What are the 4 lobes of the cerebral cortex (cerebrum)?
- Frontal lobe (responsible for motor, motivation, cognition personality etc.)
- Temporal lobe (auditory & olfactory/smell area)
- Parietal lobe (somatic sensory area)
- Occipital lobe (visual area)
What is the Cerebrum responsible for?
- Information processing
- Language
- Personality
- Conscience
What is the role of the Cerebellum?
- To coordinate motor activities
- Essential part of rapid processing of sensory info.
- role in control of posture/balance
What is the Diencephalon composed of?
- Thalamus = processing & relay center (most sensory info. passes through it)
- Hypothalamus = BIG role in homeostasis (e.g reg. body temp, food/water intake, emotional response, memory & sleep/circadian rhythms)
- Epithalamus = 2 parts; Pineal gland (endocrine organ) & Habenula (Relay center)
What is the Brain stem
- Mid brain = role in visual & auditory reflexes
- Pons = co-ord. chewing. eye movement, facial muscles, brain nuclei involved in sleep/attention/arousal
- Medulla oblongata = co-ord. processes involving equilibrium, audition, swallow/cough/vomiting, salivation etc. *also has role in respiration & cardiovascular control
What are the 2 things control of movement can be broken up into?
- Planning
- Executing
What does the planning and executing movements involve?
- occurs in no. brain regions inc. prefrontal cortex, motor cortex & motor association areas
- Motor association areas = plan complex movement (planning) & Basal ganglia modulates motor plans
- Motor cortex = charge of organising movement to occur (executing)
What is the sequence where sensory information go?
- Sensory input from eyes to visual cortex/ears to auditory cortex
- Information goes to Wernicke’s area (allows comprehension what’s communicated by order & meaning of words)
- Then goes to Broca’s area
What system helps produce emotional responses/process emotions?
Limbic system
What are some parts of the limbic system (4*)?
- Hippocampus (inv. formation, storage & retrieval of memories)
- Amygdala (gen. emotions & decision-making on emotions)
- Nucleus accumbens (important in why meds can be addictive)
- It also connects to frontal cortex to create emotion awareness (consciousness) & plan response
How much information can ppl hold in short term memory on average?
7-12 pieces of info.
