Lecture 1 & 2 : Organisation Of The Nervous System + CNS Structure Flashcards
How many neurons roughly are there and does the number change?
- 86 Billion Neurons
- Not making anymore, can’t replace but need to repair
What is the prefrontal cortex responsible for?
- Forward Planning, decision making —> setting goals
- Also grows the last -> needs myelination
What are Ependymal cells?
- Type of glial cell that line the fluid filled spaces in brain and spinal cord.
- Produce cerebrospinal fluid
What are neuroglia?
- Cells that provide metabolic support or immune protection for neurones
- 10x as many neuroglia than neurons
What are the types of neuroglia in the Central nervous system (Brain and Spinal Cord) and the peripheral nervous system?
- Ependymal cells
- Oligodendrocytes
- Astrocytes
- Microglia
What are Oligodendrocytes and what are their functions?
- Produce myelin which are protective and insulating sheaths over nerve fibres (axons)
What are Astrocytes and what are their functions?
- Star shaped cells
- Have connection to blood vessels and maintains homeostasis of blood flow, transmitters, extracellular ions for neurons
- Formation and support of the blood brain barrier
What are microglia and what are their function?
- Fight off infection
What are some of the features of a neurone?
- Dendrites
- Nucleus
- Cell body (soma)
- Axon hillock
- Axon
- Node of Ranvier
- Myelin
- Terminal boutons (axon terminals)
What are the function of dendrites?
- Tree branch like structure from cell body
- Receive electrical impulses from other neuron’s and the environment in the form of chemical messengers (neurotransmitters)
What is an axon hillock and node of ranvier?
- Axon Hillock: Bump in cell body that takes all the signals/ info and decides if it will pass the message or not
- Node of ranvier: Gaps in the myelin sheath in the axon. Allows ions to diffuse in and out propagating electrical signalling. Action potential happens in these gaps
What is the direction of flow of info in a neuron?
- Unidirectional
- Flows from dendrites/ cell body to axon terminal
What are some features of a neuronal synapses?
- Presynaptic axon terminal and post synaptic dendrite
- Mitochondria
- Synapse and synaptic cleft
- Synaptic Vesicles and receptors
What do the words anterior, posterior, superior, dorsal, ventral and inferior mean
- Anterior: In front of
- Posterior: Behind
- Superior: Higher/ above
- Dorsal: Relating to the back/ posterior of structure
- Ventral: In front and lower side (abdomen)
- Inferior: Lower/ below
What are the main brain structures?
- Cortex: outer layer of cerebrum (brain)
- Gyrus: Raised tissue layer of cortex
- Sulcus: Trough of cortex
- Cerebellum
- Brainstem: Connects brain to spinal cord
- Spinal Cord
What is the Cerebellum important for?
- Mini brain and contains more neurons that rest of brain
- Co-ordinating movement and balance, language processing and memory (cognitive)
What does grey matter and white matter consist of?
+ what is a longitudinal fissure
- Grey matter: Dendrites and Cell body of neurons
- White matter: Axons and myelin sheaths make it white
- Groove in the middle that separates 2 hemispheres of the brain
What are the 4 lobes of the brain?
- Frontal
- Parietal
- Temporal
- Occipital
What is the Frontal Lobe responsible for?
- Motor control (movement)
- forward planning/ decision making
- recognition of smell
- speech
What is the parietal lobe responsible for?
- Identify objects
- Pain and touch sensations
- Understanding speech
What is the occipital lobe responsible for?
- Vision