The nervous system From the perspective of contemporary psychology

A survey of the nervous system Within the broad heading of the Nervous System we find many component systems and subdivisions The first are: a) The Central Nervous System – the brain and the spinal cord, and a) The Central Nervous System – the brain and the spinal cord, and b) The Peripheral Nervous System – bundles of axons connecting the spinal cord and the rest of the body. b) The Peripheral Nervous System – bundles of axons connecting the spinal cord and the rest of the body.

The spinal cord A rope of neural tissue that runs inside the hollows of the vertebrae from just above the pelvis into the base of the skull Connected to both sensory ( pain, touch, and pleasure) and motor ( contract and relax muscles) neurons Facilitates reflexes - rapid, involuntary responses to stimulus

the peripheral nervous system Divides into : Divides into : a) the Somatic Nervous System – nerves which communicate with the skin and muscles and a) the Somatic Nervous System – nerves which communicate with the skin and muscles and b) the Autonomic Nervous System – nerves which control the involuntary muscles, internal organs (heart, lungs, stomach, etc.) and glands b) the Autonomic Nervous System – nerves which control the involuntary muscles, internal organs (heart, lungs, stomach, etc.) and glands

The autonomic nervous system Two divisions: Two divisions: 1) Sympathetic – prepares your body for action, fight or flight 1) Sympathetic – prepares your body for action, fight or flight blood flows to muscles blood flows to muscles epinephrine increases heart rate epinephrine increases heart rate lungs pull in more oxygen lungs pull in more oxygen sweat forms for cooling sweat forms for cooling

2) Parasympathetic – returns your body to its resting state, conserves energy 2) Parasympathetic – returns your body to its resting state, conserves energy heart rate slows heart rate slows epinephrine cut off epinephrine cut off lungs relax lungs relax stomach resumes stomach resumes digestion digestion

The endocrine system A set of glands that produce and release hormones These hormones influence thoughts, behaviors and actions Transmitted through the blood Have a global effect as compared to the local effect of neurotransmitters Include the hypothalamus and pituitary

Hormones of note Melatonin – aids sleep, from pineal gland Oxytocin – the cuddle hormone, from pituitary gland Cortisol, Epinephrine, etc.– arousing, from adrenal glands Sex hormones (Testosterone, Estrogen, etc. – differentiate the sexes (and much more), mostly from the gonads