PSY236 Lecture Notes - Lecture 8: Extracellular Fluid, Fluorescence, Citric Acid Cycle
PSY236 Week 8 Lectures:
The Nervous Systems
• Discovering the big black box
o How do we feel emotion, experience reward, see, hear, smell, co-
ordinate movement, reason or judge, learn or remember, feel pain?
Understanding basic human physiology
• Promote homeostasis
o Keeps all body cells happy
▪ Oxygen
▪ Nutrients and water
▪ Balance H+ levels (pH = 7.4)
▪ Temperature 37.2 degrees Celsius
▪ Rid waste products (e.g. CO2)
o E.g. the cardiovascular system helps promote homeostasis →
controlling body temperature, supply oxygen to cells
• All of these factors are important for cell survival
o Cells can only function correctly in the right environment
o E.g. pH (acidity and alkalinity) can greatly affect how a cell functions
▪ Too acidic → neurons are unable to send messages (acidosis)
▪ Too basic → neurons send uncontrolled messages (alkalosis)
o Death results if pH levels are out of range of 6.8 to 8.0
Nervous systems
• Central nervous system
o Cerebrum
o Cerebellum
o Brain stem
o Spinal cord
• Peripheral nervous system
o All nerves outside of the spinal cord
o Somatic NS (voluntary) the way we receive incoming touch and how
we promote motor output; we have control over everything
o Autonomic NS (involuntary)
Somatic NS (voluntary system)
• Touch comes in through the dorsal roots and out through the ventral roots to
promote muscle movement
• Motor Neurone Disease, Amyotrophic Lateral, Sclerosis = problems with
ventral roots/motor output; weakness of muscle
• Peripheral nerves
o Cranial nerves (12 pairs)
o Cervical nerves (8)
o Thoracic nerves (12)
o Lumbar nerves (5)
o Sacral nerves (5)
o Coccygeal nerve (1 pair)
• Lobes of cerebrum (cortex)
o 4 main types
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▪ temporal lobe – auditory senses, memory, emotion
▪ occipital lobe – sight, vision
▪ parietal lobe – receiving sensory input
▪ frontal lobe – all about executive functioning
o In between the primary motor cortex (part of frontal lobe) and the
primary somatosensory cortex (parietal lobe), there is the central
sulcus
• The somatic nervous system receives sensory input and delivers motor/muscle
output
• Sensory input is received through the dorsal roots to spinal cord
• Motor output is delivered via the ventral roots of the spinal cord to the muscle
• There are 6 areas that the nerves join the CNS
• There are 4 lobes of the cerebrum
• The brain receives sensory information (of touch) at the somatosensory cortex
and produces behaviour by modulating motor output from the primary motor
cortex
Autonomic NS (involuntary)
• Sympathetic → extends from thoracic and lumbar spine
o Short preganglionic nerves
o Long postganglionic nerves
• Parasympathetic → extends from cranium and sacral spine (craniosacral)
o Long preganglionic nerves
o Short postganglionic nerves
• Both are usually active BUT change intensity as the need arises
• Parallel systems that work in opposition to each other
• Increase sympathetic system results in decreased parasympathetic system
• Sympathetic – four F’s (flight, fight, fright and sex)
• Parasympathetic – non-emergency (digestion, growth, immune responses,
energy storage)
• They work against each other → scary situation arises; heart rate increases,
but you are going to decrease in gastrointestinal
Communication of brain to body
• PNS
o Somatic
o Autonomic
• Hormones releasing
o Hypothalamus and pituitary (many diff hormones)
▪ Hypothalamus regulates hormone release from the pituitary
(can release and inhibit)
o Pineal gland (melatonin) sleep hormone
• Consider speed and range of effect
o For PNS – it is very fast but is targeted
o Hormones – because they go into the bloodstream, they are slow but
ranged effect
Keeping the brain happy
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
The brain receives sensory information (of touch) at the somatosensory cortex and produces behaviour by modulating motor output from the primary motor cortex. Increase sympathetic system results in decreased parasympathetic system energy storage: they work against each other scary situation arises; heart rate increases, but you are going to decrease in gastrointestinal. Blood brain barrier: a way that the brain stops things from getting into its brain cells, strict cardiovascular supply, blood vessels in the brain don"t let things in. Important nutrients amino acids and glucose are actively transported across to csf by proteins in the capillary membrane called transporters. Brain cells: neuron network, the human brain starts with approx. 100 billion neurons (and even more glial cells: huge network for communication and complex processing, white vs. grey matter cortex, white matter = myelinated axons of the cell, grey matter = cell bodies of neurons.