Biological Bases of Behaviors Part 2 Unit 2 Biopsychology Psychology 40S C. McMurray Source: David Myers Worth Publishers

Nervous System Central Nervous System (CNS) Peripheral Nervous System (PNS) OBJECTIVE 7| Describe the nervous system’s two major divisions, and identify the tree types of neurons that transmit information through the system.

"You have brains in your head. You have feet in your shoes "You have brains in your head. You have feet in your shoes. You can steer yourself Any direction you choose.” Watch video: Human brain built for survival http://videos.howstuffworks.com/discovery/6835-human-body-built-for-survival-video.htm

Nervous System The brain is the center of the nervous system. The spinal cord and nerves are the connections. Nerves carry electrochemical signals to and from different areas of the nervous system as well as between the nervous system and other tissues and organs. Watch video clip: Neurons, how they work http://www.neok12.com/php/watch.php?v=zX784a525472754f71401a45&t=Nervous-System

The Nervous System Nervous System: Consists of all the nerve cells. It is the body’s speedy, electrochemical communication system. Central Nervous System (CNS): the brain and spinal cord. Peripheral Nervous System (PNS): the sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body.

The Nervous System

Peripheral Nervous System Somatic Nervous System: Part of the peripheral nervous system that controls the body’s skeletal muscles. Autonomic Nervous System: Part of the PNS that controls the glands and other muscles. The body’s automatic actions (eg. breathing and heartbeat) OBJECTIVE 8| Identify the subdivisions of the peripheral nervous system, and describe their functions.

Autonomic Nervous System (ANS) Sympathetic Nervous System: Division of the ANS that arouses the body, mobilizing its energy in stressful situations. Known as: FIGHT or FLIGHT response Parasympathetic Nervous System: Division of the ANS that calms the body, conserving its energy. Scientific explanation of the Fight or Flight Response Sympathetic vs Parasympathetic http://www.garyfisk.com/anim/autonomicns.swf

Fight or Flight Response

Autonomic Nervous System (ANS) Sympathetic NS “Arouses” (fight-or-flight) Parasympathetic NS “Calms” (rest and digest)

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Neurons The body’s information system is built from billions of interconnected cells called neurons. A neuron is a nerve cell. Neurons communicate with each other through an electrochemical process. Neurons are the basic building blocks of the nervous system. Neural Communication

A nerve cell, or a neuron, consists of many different parts. Neuron Watch: Neurons A nerve cell, or a neuron, consists of many different parts. OBJECTIVE 3| Describe parts of a neuron and explain how its impulses are generated.

Parts of a Neuron Cell Body: Life support center of the neuron. Dendrites: Branching extensions at the cell body. Receive messages from other neurons. Axon: Long single extension of a neuron, covered with myelin [MY-uh-lin] sheath to insulate and speed up messages through neurons. Terminal Branches of axon: Branched endings of an axon that transmit messages to other neurons.

Action Potential A neural impulse. A brief electrical charge that travels down an axon and is generated by the movement of positively charged atoms in and out of channels in the axon’s membrane.

Synapse Synapse [SIN-aps] a junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron. This tiny gap is called the synaptic gap or cleft. OBJECTIVE 4| Describe how nerve cells communicate. Synapse was coined by Lord Sherrington (1857-1952) who inferred it through behavioral experiments. Cajal (1852-1934) described the synapse based on his anatomical studies of the brain.

Watch: neurotransmitters Neurotransmitters (chemicals) released from the sending neuron travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing it to generate an action potential. Watch: neurotransmitters what are neurotransmitter?

Neurotransmitters

The Endocrine System The Endocrine System is the body’s “slow” chemical communication system. Communication is carried out by hormones synthesized by a set of glands.

Hormones Hormones are chemicals synthesized by the endocrine glands that are secreted in the bloodstream. Hormones affect the brain and many other tissues of the body.

Pituitary Gland Is called the “master gland.” It releases hormones that regulate other glands. Releases the growth hormone.

Regulate metabolic rate. Produces a hormone called thyroxine. Thyroid Glands Regulate metabolic rate. Produces a hormone called thyroxine.

Adrenal Glands and Pancreas Adrenal glands secrete hormones adrenaline (epinephrine and norepinephrine) during stressful and emotional situations. Pancreas secretes insulin to regulate the level of sugar in the blood.

Gonads Sex glands are located in different places in men and women. They regulate bodily development and maintain reproductive organs in adults. Testis produce the hormone testosterone. The ovaries produce estrogen.

Pineal Gland Pineal gland produces Melatonin. Melatonin regulates the sleep cycle.

Oxytocin Oxytocin – the cuddle hormone Powerful chemical released by men and women during orgasm. It also helps cement the strong bond between a mother and her baby. It is released during childbirth. If you block the natural release of oxytocin in sheep and rats, they reject their own young. Produced in the Hypothalamus