Coordination and smooth movements require additional input Cerebellum – compares motor cortex output with what is happening in body. Important for acquiring physical skills (procedural memory) Basal nuclei – inhibits unwanted movements. Associated with Parkinson’s disease, Huntington’s disease

Basal nuclei inhibits muscle tone selects and maintains purposeful muscle activity while inhibiting useless movement monitors and controls slow, sustained contractions (posture)

Hypotonia - low muscle tone normal

Mid-brain Hypothalamus – Controls much of the endocrine system via pituitary gland Thalamus - performs some sensory processing, transmits signals to ‘higher’ areas Pineal – linked with circadian clock

Thalamus

Table 5.3 (1) Page 144 Cerebellum Brain stem Cerebellum Brain stem Midbrain Pons Cerebellum Cerebellum Midbrain Medulla Brain stem Brain stem Pons Medulla

Limbic association cortex A set of interconnected brain areas that fxn in motivation, emotion, and memory

Limbic system Involves both cortical and subcortical regions “Feeling and reacting brain” vs. thinking brain of frontal cortex. Fear, anger, pleasure and sexual drive Reward and punishment centers exist

Limbic system: amygdala Receives signals right from thalamus when experiencing fearful stimuli (emotional stimuli) Amygdala is associated with hippocampus, learning.

Memory Short-term memory – stored for a few minutes and can contain only a few items or concepts (like a phone number). Items can get ‘bumped’ from STM. Long-term memory – lasts years or more – generally stored in cortex. Includes factual info about the world, and personal events.

Hippocampus Short-term memory is converted to long-term memory using signals involving the hippocampus Hippocampus is an area where new neurons can be produced.

How we remember Storage in temporal lobes, limbic system, cerebellum Newly acquired information Usually permanently lost Short-term memory stores Rapid retrieval (Practice) Inability to retrieve Searching and readout “Forgetting” Consolidation “Remembering” Long-term memory stores Usually only transiently unable to access stores Slower retrieval, except for thoroughly ingrained memories, which are rapidly retrieved Storage in temporal lobes, limbic system, cerebellum

Alzheimer’s disease In Alzheimer’s disease, abnormal proteins cause damage to neurons (amyloid beta, tau) The hippocampus is the first to be affected

Brain stem and cerebellum Brain stem - Controls basic functions: breathing, heart rate, digestion, etc. Cerebellum maintains balance, enhances muscle tone, and coordinates skilled muscle activity

Reticular activating system Visual impulses Brain stem Reticular formation Auditory impulses Spinal cord

How long should sleep last? Humans generally require 7-8 hours of sleep 10% require more 5% require less (some have mutation on DEC2 or BHLHE41 genes). They have reduced sleep but no less NREM sleep

Our brain is not really a ‘swiss army knife’ Idea that areas of the brain distinctly focus on one sense has been discarded There is a lot of ‘cross-talk’ between the senses (i.e. what you see influences what you hear and so on) Then Now

Figure 5.28 Page 173 Cervical Cervical cord nerves Thoracic nerves Lumbar nerves Lumbar cord Cauda equina Sacral nerves Sacral cord Coccygeal nerve

Dermatome - a patch of skin innervated by the same spinal nerve

Spinal cord Spinal nerve Meninges layers Vertebra

Nerve- a bundle of peripheral axons Nerve- a bundle of peripheral axons. Spinal nerves contain afferent and efferent fibers.

Spinal nerve From receptors To effectors Interneuron Cell body of efferent neuron Interneuron Cell body of afferent neuron From receptors To effectors

Withdrawal reflex contracts relaxes Reflex arc Afferent Receptor Afferent pathway Integrating center Efferent pathway Effector organs Withdrawal reflex Thermal pain receptor in finger Ascending pathway to brain Afferent Pathway Stimulus Biceps (flexor) contracts Efferent Pathway Integrating center (spinal cord) Triceps (extensor) relaxes Hand withdrawn Effector organs Response