Central Nervous System Flashcards
What is a pathway, tract or commissure in the CNS?
No nerves in the CNS –
a group of axons travelling together is called a pathway, tract or commissure
What are nuclei in the CNS?
Cell bodies of neurons of similar functions often cluster together – in the CNS these clusters are called nuclei
(in the PNS they are called ganglia)
What are the parts of the brain before we are born?
What develops from the Forebrain?
Cerebrum, Lobes
Thalamus, Hypothalamus
What is included in the brainstem?
Medulla Oblongata
Pons
Midbrain
What develops from the Hindbrain?
- Cerebellum
- Pons
- Medulla Oblongata
What are the parts of The Cerebrum?
3
- Cerebral cortex -> superficial, grey matter, mostly cell bodies
- White matter -> deep, tracts of myelinated axons
- Subcortical nuclei -> grey matter, deep to white matter
Left and right cerebral hemispheres
Cerebrum
What is the Corpus Callosum?
Massive bundle of axons that connects the left and right hemispheres allowing communication
Cerebrum
What is The Cerebral Cortex?
4
- Site of complex integration of information
- Folding of the cerebral cortex increases its surface area
- Gyri/folds (s. gyrus) and sulci (s. sulcus)
- Lobes: frontal, parietal, occipital, temporal
- perception, skilled movements reasoning, learning and memory
Cerebrum
What are Gyri?
(folds)
gyri allows higher order reasoning and complex decision making
Cerebrum
What are the Lobes of the Brain?
frontal, parietal, occipital, temporal
Cerebrum
What is the Subcortical Nuclei?
- Deep within the cerebral hemispheres
- Grey matter
- Important for controlling movement and posture and complex aspects of behaviour
Cerebrum
What is the Limbic System? (4)
What makes it up? (4)
- Functional system containing both grey + white matter
- Frontal lobe + temporal lobe + thalamus + hypothalamus + the pathways that connect them
- Learning, emotional experience and behaviour
- Visceral and endocrine functioning
What makes up The Diencephalon?
- Thalamus
- Hypothalamus
- Epithalamus
The Diencephalon
What is the Thalamus?
- Collection of large nuclei
- Integration center for most inputs to the cortex
- Arousal, focusing attention and filtering extraneous information
The Diencephalon
What is the Hypothalamus?
- Collection of nuclei
- Master command center for neural-endocrine coordination (internal homeostatic regulation)
- Connected to and regulates the pituitary gland
The Diencephalon
What is the Epithalamus?
Contains the pineal gland (participates in control of circadian rhythm through release of melatonin)
What is The Cerebellum?
What can block it?
- Cerebellar cortex -> superficial, grey matter
- Movement coordination and posture/balance control
- Almost exclusively functions in motor control
gets blocked when drinking alcohol, casues blance loss
What is The Brainstem?
What is included in it?
- ESSENTIAL FOR LIFE (breathing, heart rate, swallowing reflexes)
- Midbrain, pons, medulla oblongata and reticular formation
- Receives input from all regions of the CNS and processes it
Brain - Cross Section
What are Meninges?
- Between soft neural tissue and bones (in skull and spine)
- Protect CNS, circulate and absorb cerebral spinal fluid (CSF)
- Subarachnoid space is filled with CSF
What are the layers of the meninges?
(superficial -> deep)
Dura mater, arachnoid mater and pia mater (superficial -> deep)
What is Cerebral Spinal Fluid?
- Provides cushioning for the CNS
- Circulates the brain through the ventricles
- Samples of CSF can provide diagnostic information about the brain
What secretes Cerebral Spinal Fluid?
Produced by ependymal cells in the choroid plexus
What forms The Blood Brain Barrier?
Formed by astrocytes and the cells that line the smallest blood vessels in the brain
What is The Blood Brain Barrier?
Exchange of substances between the blood and extracellular fluid of CNS is highly regulated compared to other organs
- Lipid-soluble solutes can easily pass the blood brain barrier
- Substances that cannot diffuse across cell membranes rely on transport proteins (i.e.,
The Blood Brain Barrier
What are Tight Junctions?
protein complexes that restrict the movement of polar molecules into the CNS