Unit 2 – The Brain and the Body

 The brain is the seat of:
 Cognition
 Affect
 Consciousness
 It’s characteristics affect the nature of our thoughts, feelings and behaviors.

 Many types of systems rolled into one nervous system.
 Communication system: when you touch and notice how something feels, the sensation is communicated to your brain.
 Processing system: When you think, you process ideas.
 Storage system: storing memories
 Electrochemical system: operates using both electricity and chemicals

 Neurons: Nerve cells that serve as the building blocks of the nervous system. They send signals to the brain, muscles and glands.
 You have over 100 billion neurons in your brain sending signals. Signals help different parts of your body communicate.
 Swat a mosquito.
 Wave to a friend.
 Neurotransmitters: Chemical signals sent by neurons. They work quickly to help you react to anything going on around you.
 Neural Impulses: An electric current that travels from the dendrites through the axon to the terminal branches to be fired off to another neuron. (Action potential process)
 Dendrites: Branchlike extensions of a neuron that pick up info from a neighboring cell and transmit it to the cell body.
 Nerve Fibers: Neurons strung together in chains that run through the body
 Other neurons are packed together in the brain and spinal cord.
 Synapses: Tiny gaps btw neurons where neurotransmitters pass signals from one neuron to the next.
 View 2.1.2 clip: “Part of Neuron”: http://courses.apexlearning.com/apps/AceWeb/launch2.do?enrollmentID=23686419&outlineID=477353108&section
=0&page=4

 A message (nerve impulse) travels down the axon of a neuron until it gets to the end, when the neuron releases molecules to make the next neuron fire.
 Axon: The long, hair-like extension of a nerve cell that transmits electrical impulses as outgoing messages, outward from the cell’s body.
 Neural impulses travel from one neuron to the next.
 View clip 2.1.2 pg 6: http://courses.apexlearning.com/apps/AceWeb/launch2.do?enrollmentID=23686419&out lineID=477353108&section=0&page=6

 You have one nervous system with six main subdivisions. Each subdivision of your nervous system has a different set of jobs.
 Two main subdivisions:
 Central nervous system: Portion of the nervous system consisting of the brain and spinal cord.
“Center”
 Peripheral nervous system: Portion of the nervous system that relays information between the central nervous system and the rest of the body. (runs through most of the body)
 Unit 2.1.2 – pg. 8: http://courses.apexlearning.com/apps/AceWeb/launch2.do?enrollmentID=23686419&outlineID=
477353108&section=0&page=8

 Central Nervous System consists of the brain and spinal cord.
 Cerebral Cortex, which is involved in a variety of higher cognitive, emotional, sensory, and motor functions is more developed in humans than in any other animal.
 Cerebral Cortex is what we see when we picture a brain – gray matter with multitude of folds that cover the cerebrum.
 Brain is divided into TWO hemispheres: left (language, the rational half of the brain, associated with analytical thinking and logical abilities) and right (more involved with musical and artistic abilities.

 Left Brain / Right Brain Activity in MPR

 Science of Psychology / Brain evolves https://www.youtube.com/watch?v=yE6VTvxkhFs

•Motor Cortex
•Motor behavior
•Expressive
Language
•Higher cognitive processes
•Orientation to a person, place, time, situation.
• Somatosensory
Cortex
• Process of touch, pressure, temperature or pain.
• Visual Cortex
• Interpretation of visual information.
• Auditory Cortex
• Receptive language
• Understanding emotion and memory

 Your peripheral nervous system is just as important as your “central”.
 Subdivisions of Peripheral Nervous System
 SOMATIC NERVOUS SYSTEM: Carries messages to and from the sense organs, skin and muscle.
Regulates the actions of the skeletal muscles.
 Controls your muscles.
 Sends signals from senses such as vision
 When you see a piece of candy and reach for it – your somatic nervous system is at work.
 AUTONOMIC NERVOUS SYSTEM: Regulates the action of organs and glands such as heart rate, breathing, blood pressure, etc. It is divided into sympathetic and parasympathetic nervous systems.
 Controls functions you don’t have to think about
 Digestion
 Body temperature

Central
The Nervous
System
Peripheral
Autonomic
Sympathetic Parasympathetic
Somatic

 Nervous System – Education Portal (pass out worksheet)

 https://www.youtube.com/watch?v=W4N-7AlzK7s#t=169

Unit 2 – The Brain and the Body

 Endocrine System is composed of a series of glands throughout the body.
 Glands secrete chemical messengers called HORMONES into the bloodstream.
 Nervous System vs. Endocrine System
 Both systems allow body to communicate internally to affect body functions and behavior.
 Difference: Nervous System uses both electrical and chemical signals in its communication system. Endocrine system ONLY uses chemical signals.

 There are 4 main components of the Endocrine System:
1.
Glands
 Make and send messages through the bloodstream to specific receptor sites
2.
Hormones: A chemical secreted by endocrine glands which carries instructions to the body.
 Tell our body to do things (digest food, absorb vitamins, etc.)
3.
Bloodstream
4.
Receptors: a specific site on a cell designed to recognize and accept a specific hormone.
 There has to be one specific receptor site for each hormone message. When the hormone matches up with it’s specific receptor, then the body knows what it’s supposed to do next.

 Hormones and receptors have to match up perfectly or they will not send a message.
 Endocrine System Hormone/Receptor Activity:
 You will be assigned as a “hormone” or “receptor”
 If you are a hormone, search around the classroom until you find the receptor that is a perfect match for you.
 If you are a receptor, stand still and wait for your hormone to come find you.

 Located in the brain just below the hypothalamus.
 Considered the “master” gland because it activates other glands to release other hormones.
 Secretes one variety of ENDORPHINS:
Neurotransmitters that cause a feeling of well-being.
The body’s natural painkillers!
 Example: a “Runner’s High”

 Located in the neck below the voice box (or larynx)
 Produces the hormone thyroxin, which regulates the rate at which the body uses energy (the metabolic rate)
 Butterfly-shaped with two wings represented by the left and right thyroid lobes, which wrap around the trachea.

 Pancreas gland regulates the body’s sugar levels through the production of INSULIN.
 Insulin causes the body to metabolize blood sugar and thereby get energy from it.
 Diabetes patients have a disorder of the pancreas that prevents insulin production so that they cannot metabolize sugar in the blood.

 ADRENAL GLANDS help control heart rate, blood pressure, and other important body functions.
 There are two adrenal glands located on top of each kidney.
 Adrenals produce “epinephrine” also referred to as ADRENALINE: Increases the heart rate and respiration.
 Adrenaline is released when the
SYMPATHETIC NERVOUS SYSTEM signals the body to prepare for a “fight or flight” situation.
 Excitement and nervousness activate your adrenal glands.

 THYMUS produces special blood cells called T-CELLS, which help the body fight off diseases.
 It produces a hormone called
THYMOSIS – which stimulates the maturation of cells in other parts of the lymphatic system.