Week 12: Anatomy of the Central nervous system Flashcards
Where has been greatest growth in evolution of brain?
Vison, memory, speech, motor of hand
Rostral
- towards forehead, towards apex
Caudal
Towards occipital lobe, feet, spinal cord
Medulla Oblongata
Breathing - chemoreceptors in carotid body - sends signal here. Reflexes - vomiting, coughing, sneezing, swallowing - motor neurons responsible for mevment of pharynx and tongue. CV funciton - BP and HR
Proreptiliean
Brainstem and hypothalamus = vital funcitons, reliable, instinctive
Pons
Consciousness - regulating wakefulness. Origins of several cranial nerves and large nerve tracts - control voluntary movement
Pons lesions
On motor tracts = locked-in syndrome
Midbrain
Defensive behaviors (fight or flight), Head orienting reflexes (owards visual stimuli - see potentially threatening things), integration of complex movement
Parkinson’s disease
Destruction of substantia nigra
Where specifically are defensive behaviours controlled
Periaqueductal gray matter (midbrain) - integrates motor responses, CV responses, analgesia
Where specifically are head-orienting reflexes controlled
Superior colliculus - columns of neurons respond to specific parts of 3D space
Diencephalon parts (+function)
Thalamus - process sensory information on the way to cortex
Hypothalamus - homeostatic mechanisms
Sub-thalamus - complex movements.
Epithalamus - circadian rhythm
Paleomammalian
Limbic system - early mammalian brains - memories of behaviours as agreeable or disagreeable, responsible for emotions
Limbic brain structures
Hippocampus, amygdala, hypothalamus, cingulate cortex and prefrontal cortex
What does the limbic system process?
Emotions (fear, aggression, pleasure) - records them and integrates them with a motivational system - shapes behaviours to incoming stimuli - based on instincts and past experiences
