Biology and Behavior Chapter 3

The Nervous System Central Nervous System – consists of the brain and spinal cord. Central Nervous System – consists of the brain and spinal cord. Peripheral Nervous System – made up of nerve cells that send messages between the central nervous system and all the parts of the body. Peripheral Nervous System – made up of nerve cells that send messages between the central nervous system and all the parts of the body.

Neurons – nerve cells that communicate with each other throughout our body. Neurons – nerve cells that communicate with each other throughout our body. –Everyone has more than 100 billion of them. Most in your brain.

–Cell body: produces energy that fuels the activity of the cell –Dendrites: fibers that receive information from other neurons

–Axon: carries messages away from the cell to other neurons. –Myelin: insulates the axon

–Synapse: junction between the axon terminals and dendrites. –Neurotransmitters: chemicals that are released from the axon. Sends a message.

There are many types of neurotransmitters. They are involved in a variety of behaviors from yawning to exercising. There are many types of neurotransmitters. They are involved in a variety of behaviors from yawning to exercising.

Central Nervous System Central Nervous System –Spinal Cord: extends from the brain down the back. It is a column of nerves protected by bones. If you touch a hot surface, a message goes immediately to your spinal cord telling your muscles to remove your hand.

Peripheral Nervous System Peripheral Nervous System –Somatic – transmits sensory messages to the central nervous system. Touch, pain, change in temperature.

–Automatic: regulates body’s vital functions. Heartbeat, breathing, digestion and blood pressure.

Sympathetic – activated when a person is going into action. Prepares the body to confront the situation or to run away. “Fight or Flight”. Suppresses digestion, increase in heart rate etc. Sympathetic – activated when a person is going into action. Prepares the body to confront the situation or to run away. “Fight or Flight”. Suppresses digestion, increase in heart rate etc.

Parasympathetic – restores the body’s energy. Normalized heart rate and blood pressure Parasympathetic – restores the body’s energy. Normalized heart rate and blood pressure

The Brain Divided into 3 Parts: Divided into 3 Parts: –Hindbrain: Medulla – vital functions such as heart rate, blood pressure and breathing Medulla – vital functions such as heart rate, blood pressure and breathing Pons – regulates body movement, attention, sleep and alertness Pons – regulates body movement, attention, sleep and alertness

Cerebellum – Latin for “little brain”. Balance and coordination Cerebellum – Latin for “little brain”. Balance and coordination –Midbrain: Vision, learning, and Vision, learning, and attention attention

–Forebrain: Complex thinking processes. Thalamus – relay station for sensory stimulation (ex: pain) Relays input from eyes and ears to different parts of the brain. Thalamus – relay station for sensory stimulation (ex: pain) Relays input from eyes and ears to different parts of the brain.

Hypothalamus – regulates body temperature, storage of nutrients, motivation and emotion. Hunger, thirst, aggression etc. Hypothalamus – regulates body temperature, storage of nutrients, motivation and emotion. Hunger, thirst, aggression etc.

Limbic System – memory, emotion etc. Limbic System – memory, emotion etc. Cerebrum – 70% of the weight of the brain. The ridges and wrinkles are called the cerebral cortex – outer layer of the brain. The part that thinks. Cerebrum – 70% of the weight of the brain. The ridges and wrinkles are called the cerebral cortex – outer layer of the brain. The part that thinks.

Cerebral Cortex: two sides (left hemisphere and right hemisphere) Cerebral Cortex: two sides (left hemisphere and right hemisphere) Corpus Callosum – connects the right and left sides of the brain (Right Side – Creativity, Left – Logical) Corpus Callosum – connects the right and left sides of the brain (Right Side – Creativity, Left – Logical)

Hemispheres are divided into four lobes: Hemispheres are divided into four lobes: –Frontal: Motor, Decisions, Speaking –Parietal: Skin Senses –Temporal: Hearing, Understanding Language –Occipital: Visual

Studying the Brain Researchers study accidents and brain damage to understand how the brain functions and is related to psychological functions. Researchers study accidents and brain damage to understand how the brain functions and is related to psychological functions. Some researchers have used electrical stimulation to observe behaviors associated with a particular part of the brain. Some researchers have used electrical stimulation to observe behaviors associated with a particular part of the brain.

EEG – Electroencephalogram – a device that records the electrical activity of the brain. EEG – Electroencephalogram – a device that records the electrical activity of the brain. Scans – Use computer images to study the brain. Scans – Use computer images to study the brain. –CAT Scan – X-ray beams help piece together a 3D view of the brain.

–MRI – uses radio waves and magnetic fields. More detail than a CAT Scan –PET – Positron Emission Tomography – show brain activity rather than a snapshot