The Nervous system & the endocrine system Mrs. Hensley Ap psych

What are the functions of the nervous system’s main divisions? The nervous system IS AN INTEGRATED NETWORK Central nervous system: the brain and spinal cord are located in the center of the body Peripheral nervous system: fingers and toes lie in the outermost areas of the body from the center, or the periphery of the body Somatic Nervous system: volunteer work is done by choice, so the body’s voluntary actions are controlled by this nervous system Autonomic nervous system: autonomic sounds similar to the word automatic, and the body’s automatic actions (breathing, heartbeat, etc) are controlled by this nervous system Autonomic nervous system is a key player for emotions, stress, and health. (refer to pg. 59)

Figure 3A.7 The functional divisions of the human nervous system © 2010 by Worth Publishers

Sympathetic and parasympathetic The sympathetic and parasympathetic nervous systems together make an opponent process system. Sympathetic: causes the body to rise to the challenge it faces (arouses and expends energy) Parasympathetic: causes the body to calm after the challenge has been addressed (conserves energy, calms) The opposition creates homeostasis-balance in the body

central NERVOUS SYSTEM THE BRAIN ENABLES HUMANITY-THINKING, FEELING, AND ACTING Brain’s neurons cluster into work groups-neural networks Spinal cord is an information highway connecting the peripheral nervous system to the brain The brain processes the sensory info & decides what to do Sensory info enters the body through receptor cells Motor nerves receive commands from the brain and react

Have you ever jerked away from a hot surface only to feel the burn after a delay? Interneurons make reflexes happen These cells in the spinal cord process motor responses quickly to protect the body from harm (without interneurons, you would experience severe burns in you left your hand on the hot surface long enough to process both the heat and the pain before jerking away!)

Figure 3A.10 A simple reflex © 2010 by Worth Publishers

The endocrine system Endocrine system’s glands secrete hormones (chemical messengers) Influence our interest in sex, food, aggression Some hormones are chemically identical to neurotransmitters Refer to pg. 63 the hypothalamus is the control center of the endocrine system. The hormones of the adrenal glands are described in the text. Others are described here: 1. The anterior pituitary secretes growth hormone. Too little produces dwarfism; too much results in gigantism. 2. The posterior pituitary secretes vasopressin (in addition to oxytocin), which constricts blood ves - sels and raises blood pressure. 3. The thyroid releases thyroxine and triiodothyro - nine, which increase metabolic rate, growth, and maturation. 4. Attached to the thyroid, the parathyroids release parathyroid hormone (parathormone), which increases blood calcium and decreases potassium. 5. The pancreas secretes insulin, which regulates the level of sugar in the bloodstream by increasing entry of glucose to cells (see also Unit 8A). 6. The ovary secretes estrogen, which promotes ovu - lation and female sexual characteristics. 7. The testes release the androgens, which promote sperm production and male sexual characteristics.

Figure 3A.11 The endocrine system © 2010 by Worth Publishers

Neurotransmitters vs hormones Hormones and neurotransmitters are the same Only differ on where they are manufactured and located Neurotransmitters are manufactured in neurons and located in the nervous system Hormones are manufactured by glands and based in the body and bloodstream