1. The Nervous & Endocrine System How our body’s communication system maintains homeostasis Chapter 29

2. The Division of the Nervous System B rain and spinal cord R eceives stimuli and coordinates response M otor neurons, carry impulse to muscles and glands Body to the CNS Displays response to organs and glands Sensory neuron carries impulse from sense organs to CNS Divided into Sensory Motor Somatic –conscious control Autonomic - involuntary Central Nervous System Peripheral Nervous System

3. Three types of Neurons Neuron = Nerve cell Sensory Neuron- carries nerve impulse from sense organs to brain and spinal cord, PNS to CNS Motor Neuron- Carries nerve impulse from the brain and spinal cord to the muscles and glands, CNS to PNS Interneurons - connect sensory neurons with motor neurons and carry nerve impulses between them

4. How an external stimuli becomes a response

5. Neuron Physiology Cell body- where most metabolic activities take place Dendrites - receive nerve impulse and transmit to cell body Axon - carries nerve impulse away from cell body Myelin sheath- covers axon, acts as a insulator for electrochemical impulses Nodes - gaps in the myelin sheath, nerve impulse jumps from node to node Synapse - area where one neuron transfers impulse to an adjacent neuron

6. Nerve Impulse All or None Principle Neurotransmitters (chemicals) are released from the axon and transmit impulse across synapse by binding to receptor sites on dendrite of adjacent neuron Impulses are self-propagating, like dominos

7. Endocrine System Made up of glands that release their products into the bloodstream. These hormones broadcast chemical messages throughout the body

8. REFLEX ARC Immediate response from our body due to a painful stimulus Faster reaction time due to the initial bypass of the brain. Nerve impulse takes a shorter route through the nervous system Receptor → Sensory Neuron → Spinal Cord → Motor Neuron → Effector

9. The Endocrine system is regulated by feedback mechanisms that function to maintain homeostasis The body’s response to a hormone is slow, several minutes to several days

10. Major Glands  Pituitary  Thyroid  Adrenal  Pancreas  Gonad

11. The major glands PituitaryThyroid Pancreas AdrenalGonad Gets direction from hypothalamus Metabolism Calcium level Blood glucose level Fight or flight syndrome Reproduction and sex characteristics GH ADH FSH TSH T3 T4 Calcitonin Insulin Glucagon Epinephrine Estrogen Androgen Progesterone

12. Negative Feedback Mechanism of Blood Glucose, Glucagon, and Insulin