By John Collector (Pg of Blue Book)

The nervous system consists of the central nervous system (CNS) and peripheral nerves, and is composed of cells called neurons that can carry rapid electrical impulses. *Note: The central nervous system consists of the brain and spinal chord. The peripheral nervous system consists of nerves that connect all parts of the body to the central nervous system. Obj. 1

Draw and label a diagram of the structure of a motor neuron. Note: Wow! Cool! Obj. 1

(State that) nerve impulses are conducted from receptors to the CNS by sensory neurons, within the CNS by relay neurons, and from the CNS to effectors by motor neurons. Note: This man is extremely nervous Obj. 1

Define - Resting potential (depolarization): The membrane potential that would be maintained if there were no action potentials (no voltage-gated channels), synaptic potentials, or other active changes in the membrane potential. - Action Potential (polarization): A pulse-like wave of voltage that travels along several types of cell membranes. Obj. 1

Explain how a nerve impulse passes along a non- myelinated neuron: -In non-myelinated axons, the nerve impulse is going to be produced when the action potential accross a membrane makes a wave of depolarization followed by a wave of repolarization. With the absence of the myelin, the impulse is transmitted continuously throughout the membrane. Obj. 3

Explain the principles of synaptic transmission. - Answer on next slide… Obj. 3

Step 1. The neurotransmitter is manufactured by the neuron and stored in vesicles at the axon terminal. Step 2. When the action potential reaches the axon terminal, it ﾊ causes the vesicles to release the neurotransmitter molecules into the synaptic cleft. Step 3. The neurotransmitter diffuses across the cleft and binds ﾊ to receptors on the post-synaptic cell.Step 4. The activated receptors cause changes in the activity of the post-synaptic neuron. Continued…

Step 5. The neurotransmitter molecules ﾊ are released from the receptors and diffuse back into the synaptic cleft. Step 6. The Neurotransmitter is re- absorbed by the post synaptic neuron. This process is known as Reuptake.

(State that) the endocrine system consists of glands that release hormones that are transported in the blood. Note: This was necessary Obj. 1

(State that) homeostasis involves maintaining the internal environment between limits, including blood pH, carbon dioxide concentration, blood glucose concentration, body temperature, and water balance. Note: When it comes to homeostasis, this man knows it all. - The internal environment consists of blood and tissue fluid. Obj. 1

Homeostasis involves monitoring levels of variables and correcting changes in levels by negative feedback mechanisms. - Another way of thinking about it: Your body has mechanisms which execute functions to maintain the equilibrium of levels such as body temp. and blood glucose level. Obj. 3

Explain the control of body temperature, including the transfer of heat in blood, and the roles of the hypothalamus, sweat glandes, skin arterioles, and shivering. Responses to chillingResponses to overheating -Skin arterioles become narrower and they bring less blood. The blood capillaries in the skin do not move, but less blood flows through them. The temperature of the skin falls, so less heat is lost from it to the environment. -Skeletal muscles do many small rapid contractions to generate heat. This is called shivering. -Sweat glands do not secrete sweat and the skin remains dry. -Skin arterioles become wider, so more blood flows through the skin. This blood transfers heat from the core of the body to the skin. The temperature of the skin rises, so more heat is lost from it to the environment. -Skeletal muscles remain relaxed and resting, so that they do not generate heat. -Sweat glands secrete large amounts of sweat making the surface of the skin damp. Water evaporates from the damp skin and this has a cooling effect. Obj. 3

Explain the control of blood glucose concentration, including the roles of glucagon, insulin, and alpha and beta cells in the pancreatic islets. Responses to high blood glucose levelsResponses to low blood glucose levels -Beta cells in the pancreatic islets produce insulin. -Insulin stimulates the liver and muscle to absorb glucose from the blood and convert it to glycogen. Granules of glycogen are stored in the cytoplasm of theses cells. Other cells are stimulated to absorb glucose and use it in cell respiration instead of fat. These processes lower the blood glucose level. -Alpha cells in the pancreatic islets produce glucagon. glucagon stimulates liver cells to break glycogen down into glucose and release the glucose into the blood. This raises the blood glucose level. Obj. 3

Distinguish between type I and type II diabetes. Type 1- Type 1 diabetes is an autoimmune disease that results in the permanent destruction of insulin producing beta cells of the pancreas. Type 1 is lethal unless treatment with exogenous insulin via injections replaces the missing hormone. Type 2-a metabolic disorder that is primarily characterized by insulin resistance, relative insulin deficiency and hyperglycemia. It is often managed by engaging in exercise and modifying one's diet. Obj. 2