Chapter 3 Biological Bases of Behavior MS SAINTPAUL

Chapter 3: Biological Bases of Behavior MS. SAINT-PAUL A. P. PSYCHOLOGY

Essential Question How are human thought and behavior affected by the following: • The Nervous System • The Endocrine System • The Brain • Genetics

Chapter 3 -A (A): The Nervous It starts with an individual nerve cell called a NEURON

The Neuron: The messenger n. Neuron: n Basic building block of the nervous system A neuron exists to perform 3 main tasks: 1. ) Receive information from the neurons that feed it. 2. ) Carry information down its length. 3. ) Pass the information on to the next neuron.

Parts of the Neuron

How does an Neuron work http: //www. youtube. com/watch? v=C 4 Gt 322 -Xx. I#t=173

Three (3) Types of Neurons are broken into three categories based on their location and function: n. Sensory Neurons ( Afferent nerves): n The sensory neurons communicate all of your sensory experience to the brain, including vision, hearing, taste, touch, smell, pain and balance. n Carry incoming information from sensory receptors to the brain/spinal cord n E. g. Perceiving something as “hot” (Converting external stimulus into internal electrical impulses) n. Motor Neurons (Efferent nerves): n Carry outgoing information from the brain/spinal cord to the muscles/glands n E. g. Clenching a fist n. Interneurons: n n Make up the majority of our neurons Located within the brain/spinal cord Communicate internally between sensory inputs and motor outputs E. g. Reflexes ( Subconscious or involuntary response to external stimulus)

The Neuron n. Provide an example of information that sensory neurons may transmit. n. Provide an example of information that motor neurons may transmit. n. Provide an example of information that interneurons may transmit.

The Firing of a Neuron n. Neurons transmit messages when stimulated by our senses, or triggered by chemicals of other neurons n Resting Potential: n When a neuron is not sending a signal, it is "at rest. ". . n Fluid interior of axon: negatively charged ions n Fluid exterior of axon membrane: positively charged ions n Absolute Threshold: n Excitatory signals (accelerator) minus inhibitory signals (brakes) must reach minimum intensity n Level of stimulation required to trigger a neural impulse (action potential) n Action Potential: n When the cell becomes excited, it triggers, which reverses the charge and causes the electrical signal to race along the axon. n Neural impulse (Brief electrical charge that travels down an axon) n Depolarization occurs ( axon that is firing) n “All-or-None” Response (The axon either “fires” or it does not. )

The Firing of a Neuron

Review n. What is a neuron? n. Differentiate between the 3 types of neurons: n. Sensory Neurons n. Motor Neurons n. Interneurons n. Discuss the functions of the following parts of the neuron: n. Dendrites n. Axon n. Myelin Sheath n. Terminal Branches n. What causes neurons to fire?

Reminder n. Tuesday & Wednesday (October 10 & 11) n. Chapter 3 -A: In class Project bring Candy n Skittles n Gummy worms or Nerd rope n Octopus Gummy n Laffy Taffy n Etc.

Chapter 3 -A (B): Neural Communication and Neurotransmitters

Review n. What is a neuron? n. Provide an example of information that each of the following neurons may transmit: n Sensory Neurons n Motor Neurons n Interneurons n. What causes neurons to fire?

Neural Communication n. What part of the neuron receives messages from other cells? n. What part of the neuron sends messages to other cells?

Neural Communication n. Neurons interact so closely that, even with a microscope, it is difficult to determine where one neuron ends and another begins n. Synapse: n The junction between the axon tip of the sending neuron and the dendrite of the receiving neuron n The gap between neurons is called the synapse, synaptic space or synaptic cleft n Synaptic gap (less than one-millionth of an inch wide) n Neurons do not actually touch each other to pass on information. n The synapse acts as an electrical insulator, preventing an electrical charge from racing to the next cell. n Composed of the terminal button of one neuron, the synaptic space, and the dendrites or cell body of the receiving neuron

Neurotransmitters: n. Chemical messengers that cross the synaptic gaps between neurons n. Bind to receptor sites on receiving neurons n. Influences whether receiving neuron will generate a neural impulse n. Reuptake: n. A neurotransmitter’s reabsorption by the sending neuron

Neural Communication

**Neurotransmitters can function differently depending on where they are located in the nervous system.

How Drugs Alter Neurotransmittion Agonists Vs. Antagonists: Drugs and other chemicals affect brain chemistry at synapses, either by amplifying (agonists) or blocking (antagonists) a neurotransmitter’s activity.

Chapter 3 -A (D): The Nervous System

Information coverage n. What is the nervous system? n. What is the role of the nervous system on human thought and behavior?

The Nervous System n. The body’s speedy, electrochemical communication network n. Two types of cells in the Nervous Systems: n 1. Neurons: transmit nerve impulses n 2. Glial cells: provide support and nourishment to the nervous system; keep neurons running smoothly

The Nervous System n. Central Nervous System (CNS): n The brain and spinal cord n Interneurons communicate in the spinal cord (reflexes) n Neural networks n. Peripheral Nervous System (PNS): n The sensory and motor neurons that connect the central nervous system with the rest of the body

The Nervous System

The Autonomic Nervous System

The Peripheral Nervous System n. What are some functions of the Autonomic Nervous System? n. What are some functions of the Somatic Nervous System?

The Autonomic Nervous System n. What are some functions of the Sympathetic Nervous System? n. What are some functions of the Parasympathetic Nervous System?

The Autonomic Nervous System n. Provide an example of a situation that might cause activity within the Sympathetic Nervous System. n. Provide an example of a situation that might cause activity within the Parasympathetic Nervous System.

Review n. What is the Nervous System? n. What is the difference between the Central Nervous System (CNS) and Peripheral Nervous System (PNS)? n. What is the difference between the Autonomic and Somatic Nervous System? n. Provide 3 examples for each of the following: n. Sympathetic Nervous System n. Parasympathetic Nervous System

Unit 3 -A (E): The Endocrine System

The Endocrine System n. Endocrine System: n The body’s “slow” chemical communication system n A set of glands that secrete hormones into the bloodstream n. Hormones: n Chemical messengers that are manufactured by the endocrine system n Travel through the blood stream; affect other tissues n E. g. Testosterone; Estrogen

The Endocrine System n. Adrenal Glands: n. A pair of endocrine glands that sit just above the kidneys n. Secrete hormones (Epinephrine and Norepinephrine) that help arouse the body in times of stress n. Pituitary Gland: n. The endocrine system’s most influential gland n. Influenced by Hypothalamus n. Regulates growth and controls other endocrine glands

The Endocrine System n. Can you remember feeling an extended period of discomfort after some particularly stressful event? n. How long did those feelings last?

Review n. What is the Endocrine System? n How does it transmit messages? n. How does the Endocrine System differ from the Nervous System? n. What are hormones? n. What are the roles of the following glands: n Hypothalamus n Pituitary Gland n Adrenal Glands

Homework n. Reflections for Candy Neuron in class project are due Tommorrow.