The nervous systemThe nervous system

From the perspective of From the perspective of contemporary psychologycontemporary psychology

A survey of the nervous A survey of the nervous systemsystem

Within the broad heading of the Within the broad heading of the NervousNervous System System we find many component systems and subdivisionswe find many component systems and subdivisions

The first are: The first are:

a) The a) The Central Nervous System – Central Nervous System – the brain and the spinal cord, andthe brain and the spinal cord, and

b) The b) The Peripheral Nervous System Peripheral Nervous System – – bundles of axons connecting the spinal cord and bundles of axons connecting the spinal cord and the rest of the body.the rest of the body.

The spinal cordThe spinal cord

A rope of neural tissue that runs inside the A rope of neural tissue that runs inside the hollows of the vertebrae from just above hollows of the vertebrae from just above the pelvis into the base of the skullthe pelvis into the base of the skull

Connected to both Connected to both sensorysensory ( pain, touch, ( pain, touch, and pleasure)and pleasure) and and motor motor ( contract and ( contract and relax muscles)relax muscles) neuronsneurons

Facilitates Facilitates reflexes - reflexes - rapid, involuntary rapid, involuntary responses to stimulus responses to stimulus

the peripheral nervous systemthe peripheral nervous system

Divides into :Divides into : a) the Somatic Nervous System – a) the Somatic Nervous System –

nerves which communicate with the skin nerves which communicate with the skin and musclesand muscles and and

b) the Autonomic Nervous System – b) the Autonomic Nervous System – nerves which control the involuntary nerves which control the involuntary muscles, internal organs (heart, lungs, muscles, internal organs (heart, lungs, stomach, etc.) and glandsstomach, etc.) and glands

The autonomic nervous systemThe autonomic nervous system

Two divisions:Two divisions:

1) Sympathetic – prepares your body for 1) Sympathetic – prepares your body for action, action, fight or flightfight or flight

blood flows to musclesblood flows to muscles epinephrine epinephrine increases heart rateincreases heart rate lungs pull in more oxygenlungs pull in more oxygen sweat forms for coolingsweat forms for cooling

2) Parasympathetic – returns your body 2) Parasympathetic – returns your body to its resting state, conserves energyto its resting state, conserves energy

heart rate slowsheart rate slows

epinephrine epinephrine cut offcut off

lungs relaxlungs relax

stomach resumes stomach resumes

digestiondigestion

The endocrine systemThe endocrine system

A set of glands that produce and release A set of glands that produce and release hormoneshormones

These hormones influence thoughts, These hormones influence thoughts, behaviors and actionsbehaviors and actions

Transmitted through the bloodTransmitted through the blood

Have a Have a global global effect as compared to the effect as compared to the local local effect of neurotransmitterseffect of neurotransmitters

Include the Include the hypothalamus hypothalamus and and pituitarypituitary

Hormones of noteHormones of note

MelatoninMelatonin – aids sleep, from pineal gland – aids sleep, from pineal gland

OxytocinOxytocin – the – the cuddle hormone, cuddle hormone, from from pituitary glandpituitary gland

Cortisol, Epinephrine, Cortisol, Epinephrine, etc.– arousing, etc.– arousing, from adrenal glandsfrom adrenal glands

Sex hormones (Sex hormones (Testosterone, Estrogen, Testosterone, Estrogen, etc. – differentiate the sexes (and much etc. – differentiate the sexes (and much more), mostly from the gonads more), mostly from the gonads