The Nervous and Endocrine Systems Module 10 The Nervous and Endocrine Systems

Nervous System Central Nervous System Peripheral Nervous System Brain Spinal Cord Autonomic System Somatic System Sympathetic System Parasympathetic System

The Inner and Outer Parts of the Nervous System Central Nervous System Peripheral Nervous System

Nervous System Central Nervous System – brain and spinal cord Peripheral Nervous System (PNS) – the sensory and motor neurons that connect the central nervous system to the rest of the body Nerves – bundled axons that link the central nervous system and the muscles, glands, and sense organs Sensory Neurons (afferent) – carry incoming messages from sensory receptors to brain and spinal cord Motor Neurons (efferent) - carry outgoing information from the brain and spinal cord to the muscles and glands Interneurons – within brain and spinal cord that communicate between sensory inputs and motor outputs

Peripheral Nervous System Somatic Nervous System – controls the body’s skeletal muscles Autonomic Nervous System – controls the glands and muscles of internal organs Sympathetic Nervous System – arouses the body, mobilizing its energy in stressful situations Parasympathetic Nervous System – calms the body, conserving its energy after stressful situation is over

Central nervous system Brain Billions of neurons Neural networks – interconnected neural cells that form from experience and feedback Spinal Cord – two-way information highway connecting the peripheral nervous system and the brain Governs our reflexes – simple, automatic response to a sensory stimulus Simple reflex – single sensory, interneuron, and motor Pain reflex – happens before pain message reaches brain

Endocrine System Endocrine system – the body’s slow chemical communication system; a set of glands that secrete hormones into the bloodstream Hormones – chemical messengers manufactured by endocrine glands that travel through the bloodstream and affect other tissue Nervous system(fast, neurotransmitters, electrochemical) and endocrine system(slow, hormones, chemical) function similarly and communicate together

Endocrine glands/hormones Pituitary Gland – Located in core of brain; controlled by hypothalamus Releases growth hormone Oxytocin – enables contractions for birth, milk flow, and orgasm; also promotes pair bonding, group cohesion, and social trust Master gland – controls many glands Connection between nervous and endocrine systems Adrenal Gland – above kidneys and releases epinephrine and norepinephrine. (adrenaline/noradrenaline) Increase heart rate, blood pressure, & blood sugar to increase energy in times of stress

Endocrine glands/hormones Thyroid – controls metabolism; secretes thyroxin Parathyroid – helps regulate level of calcium in blood Pineal – secretes melatonin to control sleep patterns Pancreas – regulates the level of sugar in blood; secretes insulin. Sex Glands: Testes secrete testosterone Ovaries secrete estrogen, progesterone