By Lauren Goldenberg 5/23/11 Chapters 31 & 34 The Nervous and Endocrine Systems

- Functions of Nervous System and Neurons - Transmission of a Nerve Impulse Chapter 31.1 The Neuron

 2 Functions: - Send and receive messages in the body. - Act in response to stimuli. - Stimuli: something that causes a response.  Categorized into 2 Systems: -Central nervous System - Peripheral nervous system

 Central nervous system consists of the nerves within brain and spinal cord.  System of nerves that connects the central nervous system with the body.  Consists of many neurons.

 Neuron: - basic component of the nervous system. - A.K.A.: “nerve cell” - give off electrical signals /impulses.  Many neurons form nerves.

 Dendrite  Cell body  Myelin Sheath  Axon Terminals

 Motor Neurons: - Sends an impulse from the brain to the muscle or gland of the body.  Sensory Neurons: - Impulse is detected by sense organ and sent to brain/spinal cord.  Interneurons: - Neuron that connects sensory and motor neurons together.

A chemical signal travels down a neuron. Starting at the dendrite and cascading down the axon – An Axon is coated in an smooth layer called a “myelin sheath”. When it gets to the end of the axon, chemicals known as “neurotransmitters” are released. This process is repeated as signals jump from neuron to neuron.

- Learn about the functions of the central nervous system - Learn about how drugs and alcohol affect your brain’s health Chapter 31.2 The Central Nervous System

Consists of 2 parts: Brain Spinal Cord - Control center - Main connection between of the body. Nervous system and the - 3 Parts: brain. ~Cerebrum ~Cerebellum ~Brain stem

Addictive things such as cigarettes, drugs, or alcohol cause large release of dopamine. Lots of dopamine=High Dopamine is the neurotransmitter released due to pleasurable activities. Causes brain to reduce amount of dopamine to be released.

- Name all 5 sense organs and each of their sensory receptors - Sensory and motor division of the peripheral nervous system Chapter 31.4 The Senses

Sends electrical signals to central nervous system from sense organs Uses sensory receptors – Chemoreceptors – Photoreceptors – Mechanoreceptors – Thermoreceptors – Pain receptors

Taste Smell Hearing/balance Vision Touch

Exchanges impulses to muscles or glands from central nervous system. Somatic Nervous System: Aware of what’s happening Autonomic Nervous System: Involuntary

- Describe function of endocrine system - Be able to identify major organs and glands Chapters 34.1 and 34.2 The Endocrine System

 Function- produce hormones to control certain body actions.  What is a hormone? ~ A hormone is a chemical messenger

 A gland is a organ that makes a substance and releases it for necessary needs throughout the body.  2 types: ~Endocrine: Gland that releases fluids directly into bloodstream. Ex: pancreas. ~Exocrine: Gland that externally releases fluids. Ex: Sweat glands.

-Pituitary Gland: In command of other glands. -Pineal Gland: controls sleep and wake sequence, as well as other, everyday functions. -Hypothalamus: controls discharge of the pituitary gland, and is the link between nervous and endocrine systems.

Thyroid: Controls metabolism -Parathyroid: maintains steady calcium levels in the blood.

Adrenals: Above kidneys. Helps body prepare for and handle stress. -Pancreas: regulates glucose levels in blood by releasing sugary substance called “insulin”

-Ovaries : Found in females. Produce eggs and estrogen female characteristics. -Testes: Found in males. Produce sperm and testosterone male characteristics