Organisation of Nervous System (Weeks 1 - 3) Flashcards
Functions of brain stem
- sensation & motor control of head, neck & taste
- receives info: hearing, balance, taste
- reflexes of autonomic nervous system
- asc. & desc. info to other divisions of CNS
- regulation of alertness & arousal
Parts of brain stem
Medulla
Pons
Midbrain
Position of medulla
Caudal brainstem
Contents/role of medulla
Neuronal groups: regulation of
- blood pressure
- respiration
- taste
- hearing
- balance
- control of mm. in head & neck
Position of pons
Ventral brainstem, rostral to medulla
Role of pons
Ventral: relaying info about movement & sensation
Dorsal: breathing, taste & sleep
Contents/role of midbrain
Nuclei: linkage between components of motor system - cerebellum, basal ganglia & cerebral hemispheres
Components of auditory & visual systems
Role of cerebellum
Maintaining posture &co-ordinating head, eye & arm movements - receives that information from spinal cord, inner ear & cerebral cortex.
Minute regulation of motor output & learning motor skills
Language & cognitive functions
Contents of diencephalon
Thalamus
Hypothalamus
Role of thalamus
Gateway for sensory info from periphery - determines which info reaches cortex.
Connects cerebellum & basal ganglia with regions of cortex (cognition & mvt).
Attention & consciousness
Role of hypothalamus
Regulation of homeostasis & reproductive behaviours
Influences behaviour (highly connected with CNS)
Contents of cerebral hemispheres
Cerebral cortex (& white matter)
Basal ganglia
Amygdala
Hippocampal formation
Role of somatic sensory division
Sensory input from periphery to CNS
Includes visceral sensory division: from viscera (afferent component of ANS)
Sympathetic nervous system
Fight or flight component of ANS
Parasympathetic nervous system
Rest & digest component of ANS
Most sensory cells are…
Bipolar neurons
3 types of multipolar neurons
Motor neurons
Pyramidal neurons
Purkinje cells
Microglia
Phagocytes
Active after injury, infection, disease
Regulate apoptosis during development
Regulate neurogenesis
Maintain homeostasis
3 types of macroglia
Oligodendrocytes
Schwann cells
Astrocytes
Oligodendrocytes
Form myelin sheath in CNS
Absorb chemical neural products, release chemicals that the neuron absorbs
Schwann cells
Form myelin sheaths in PNS (wraps itself around the axon)
Absorb chemical neural products, release chemicals that the neuron absorbs
Astrocytes
Irregular shape
Most abundant
Either protoplasmic or fibrous
Contribute to formation of blood-brain barrier
Insulate neuronal groups
Regulate extracellular K+ conc.
Remove neurotransmitters from synaptic cleft
Nourish neurons through release of growth factors
Difference between protoplasmic & fibrous astrocytes
Protoplasmic - found in grey matter. Sheet-like processes
Fibrous - found in white matter. Long, fine processes
Where do brain tumours come from?
Normally glial cells (gliomas), because neurons don’t divide during life.
