The Nervous & Endocrine Systems Chapter 7 & 8

The Nervous System I. Two parts a. Central Nervous System (CNS) Includes brain and spinal cord b. Peripheral Nervous System (PNS) Nerves that connect all areas of the body to the CNS

CNS a. Brain is the largest organ b. controls voluntary and involuntary activities c. 3 parts of brain i. cerebrum 1. largest section 2. stores memory, controls movement and your senses 3. 2 halves a. Right controls lefts side of body and left controls right side of body b. Left controls speaking, reading, writing, problem solving c. Right controls activities with creativity and imagination

1. receives sensory information from from skeletal muscles and joints ii. Cerebellum 1. receives sensory information from from skeletal muscles and joints iii. Medulla 1. controls blood pressure, heart rate, & involuntary activities d. Spinal cord i. Composed of neurons and axons ii. Allows brain to communicate with the PNS

PNS i. parts include a cell body, dendrites and an axon a. Composed of neurons i. parts include a cell body, dendrites and an axon 1. dendrites receive impulses 2. axons transmit impulses 3. cell body contains organelles

b. sensory neurons i. gather info in and around the body through receptors which is processed by the CNS c. motor neurons i. carry impulses from the CNS to the body d. nerves i. bundles of axons, blood vessels and connective tissue ii. usually contain motor and sensory neurons

Endocrine System involved in the control of slower, long-term processes such as fluid balance, growth, and development uses chemical rather than electrical messages Chemical Messengers  * gland – group of cells that makes hormones for your body

Examples adrenal gland – releases epinephrine which prepares you for ‘fight or flight’ pituitary – secretes hormones that affect other glands (the master gland) pancreas – regulates blood sugar with insulin ovaries/testes – produce hormones needed for reproduction thymus – regulates the immune system thyroid – increases the rate at which you use energy parathyroid – regulate calcium levels in the blood

tell glands when to turn on and off example Feedback Controls tell glands when to turn on and off example eat a meal blood glucose increases pancreas releases insulin into blood insulin signals liver to take glucose from the blood blood sugar drops you’re hungry again Hormone Imbalance Pancreas not able to make insulin = diabetes Pituitary not able to make enough growth hormone = stunted growth Lack of iodine in diet and thyroid can’t make thyroxin = goiter