Nervous SystemStudents will learn the structure and function of the nervous system

•Key Question: How does the nervous system help the body to maintain homeostasis?

•The nervous system regulates other parts of the body by sensing and responding to conditions. For example, if your body drops in temperature, the brain will sense it and respond by causing an increase in body temperature - maintaining that stable internal environment.

• 10 Facts about your brain!

(1.5 min)

Parts of the Nervous System:

Made up of the brain, spinal cord, and nerves

Neuron: cell that carries nerve impulse information

Three parts:

1. Dendrites (#1): delivers impulse to cell body

2. Cell body (#2): contains nucleus & organelles

3. Axon (#3): carries impulse away from cell body

Label the neuron on your sheet according to the numbers above

Nerve cells have a space between them called a synapse.

When a message reaches the end of a cell, a chemical moves across the

synapse of the AXON to the DENDRITE of the next cell,

delivering the chemical “message”.

FUNCTION OF THE NERVE CELL:

Receives & responds to informationfrom inside and outside of body

- Regulates body functions through stimulus & response

- Maintains homeostasis

There are two parts to the Nervous System:

Central Nervous System (CNS):

- Brain: control center of the body

- Spinal cord: links brain with body nerves, controls reflexes. Protected by vertebrae

Peripheral Nervous System (PNS): includes all nerves branching from CNS to rest of body

So why is the brain so wrinkled?

Your brain is a really neat organ, storing all of your memories throughout your life, not to mention controlling everything you do! When you’re born, your brain is only half the size it is when you’re an adult.

If you look at a human brain, you only see about a third of its surface–the other two-thirds are hidden in its folds. If you could spread it out, it would be size of a pillow case.

But there’s another intriguing thing about those wrinkles: they are not spread uniformly across our heads. The front of the brain is more wrinkly than the back. This is intriguing, because the front of the cortex handles much of the abstract thinking.

The wrinkles allow for neurons to communicate over shorter distances, enabling humans to think fast!

After you have read the above information, write a summary sentence about it on your note page.

CNS and PNS work together to respond to stimuli in your surroundings through the five senses:

- Light

- Sound

- Heat

- Chemicals

- Pressure

1. Vision: light stimulates rods (dim light) and cones (colors) and sends impulse to brain.

Rods verses Cones!

• The retina is the back part of the eye that contains the cells that respond to light. These specialized cells are called photoreceptors. There are 2 types of photoreceptors in the retina: rods and cones.

• The rods are most sensitive to light and dark changes, shape and movement and contain only one type of light-sensitive pigment. Rods are not good for color vision.

• The cones are not as sensitive to light as the rods. However, cones are most sensitive to one of three different colors (green, red or blue). Signals from the cones are sent to the brain which then translates these messages into the perception of color. Cones, however, work only in bright light.

2. Hearing: outer ear gathers sound waves that vibrate tiny bones & fluid which sends the impulse to brain

3. Smell & Taste: molecules in air stimulate nerve cells in the nasal passages (olfactory cells) & on the tongue (taste buds)

Taste Bud “Sections”?

• The notion that the tongue is mapped into four areas—sweet, sour, salty and bitter—is wrong. There are five basic tastes identified so far, and the entire tongue can sense all of these tastes more or less equally.

• In fact, there's more to taste than sweet, sour, salty and bitter. Most scientists agree that there's a fifth distinct taste, called umami, it is common in Japanese foods, particularly kombu, a type of sea vegetable similar to kelp, and in bacon.

• There's considerable debate about the existence of a sixth taste receptor for fat, too.

4. Touch: receptors found in organs & skin detect changes in pressure, pain, and temperature

Summary video:• The Nervous System

Catch Me if You Can!

Objective: To determine your reaction time by measuring how long you take to catch a falling ruler during times of concentration and distraction.

Hypothesis: Make a hypothesis about whether you think your reaction time will be faster under normal or distracted conditions.

Remember, a hypothesis is an “If (something happens), then (something else happens).

Do not use “I” or “We believe”.

Write your hypothesis NOW!

Catch Me if You Can!

Objective: To determine your reaction time by measuring how long you take to catch a falling ruler during times of concentration and distraction.

Hypothesis: Make a hypothesis about whether you think your reaction time will be faster under normal or distracted conditions.

What You Do:

1. Have your partner hold the ruler with the 0 centimeter mark level with your thumb and forefinger. Do not touch the ruler. Focus on catching the ruler as soon as your partner releases it.

2. When your partner releases the ruler, attempt to catch it as quickly as possible.

3. Observe and record the measurement where your thumb and forefinger have caught the ruler in the chart below.

4. Use the conversion chart to change centimeters to seconds and record this data in your table. Complete four trials.

5. Once complete with normal conditions, have your partner distract you by asking you multiplication problems as you try to catch the ruler. Complete four trials under distracted conditions following steps 2-4.

Conversion Chart (bottom of first page)

Distance ruler fell

(cm)

time in Seconds (s) Distance ruler fell

(cm)

time in Seconds

(s)

2 0.06 18 0.19

4 0.09 20 0.20

6 0.11 22 0.21

8 0.13 24 0.22

10 0.14 26 0.23

12 0.16 28 0.24

14 0.17 30 0.25

16 0.18

You will be timed!

• Break into partners – find your color match – this is your partner.

• Work until the time is up. You may not finish all of the questions before time is up, this is homework. Remember to answer each question with complete sentences!

• Any questions?

• Online timer

Test your brain!

• Here is your job: name the colors of the following words. Do NOT read the words...rather, say the color of the words. For example, if the word "BLUE" is printed in a red color, you should say "RED". Say the colors as fast as you can. It is not as easy as you might think!

• The words themselves have a strong influence over your ability to say the color. The interference between the different information (what the words say and the color of the words) your brain receives causes a problem. There are two theories that may explain the Stroop effect:

• Speed of Processing Theory: the interference occurs because words are read faster than colors are named.

• Selective Attention Theory: the interference occurs because naming colors requires more attention than reading words.

So what does the brain do?

Brain Foldable

What You Need to Know:

Use the notes about the brain to fill in your graphic organizer. For each part of the brain, you should identify the main functions. When finished, cut out each section of your foldable and glue it to the appropriate tab on the brain template.

BRAIN HEMISPHERES:

The brain is made of two symmetrical parts, the right and lefthemispheres. Although they are equal in size, they carry out two verydifferent jobs. The right side of the brain controls the left side of thebody and performs tasks related to creativity and the arts. The lefthemisphere controls the right side of the body and performs tasksrelated to logic like math and science. Both hemispheres are connectedto each other by the corpus callosum, which allows the two sides tocommunicate with one another.

BRAIN HEMISPHERES:

LEFT HEMISPHERE FUNCTION: Controls the right side of the body.Considered the academic and logical side of the brain - language,reasoning, science, math, writing, and number skills.

RIGHT HEMISPHERE FUNCTION: Controls the left side of the body. Considered

the artistic and creative side of the brain - intuition, insight, art and music awareness,imagination, creativity, and 3-d form understanding.

CEREBELLUM: Cauliflower shaped part of the brain located in theback under the pons.

FUNCTION: Performs everyday voluntary (movements you chooseto carry out) tasks such as walking and writing. Helps us staybalanced and upright along with coordinating our muscles.

I’m balanced and coordinated! Yay!

How do you think a damaged cerebellum would affect the body?

For each part of the brain stem, Identify parts 1-8 and the function of each

BRAIN STEM: comprised of the midbrain, pons,and medulla

1. Thalamus: It is involved in sensory perception, controllingsleep and awake states of consciousness. It alsoregulates movement.

2. Optic Nerve: transfer visual information from the retina inthe eye to the vision centers of the brain.

3. Optic Tract: Part of the optic nerve found where thenerves of the left eye and right eye cross to create acomplete picture.

4.Pituitary: This "master gland" regulates how your otherglands operate. The pituitary gland secretes andstores hormones, which it uses to stimulate your otherglands. Hormones regulate your body’s temperature,urine production, growth, and the production of sexhormones.

5.Midbrain: Regulates body movement, visionand hearing.

6.Pons: Links to the cerebellum to help withposture and movement. The Pons serves as amessage station between several areas of thebrain. It helps relay messages from the cortexand the cerebellum. Controls our sleepingstates and dreams.

7.Medulla Oblongata: Maintains involuntary bodyfunctions necessary for life such as breathing,swallowing, blood pressure, and heart rate

8.Spinal Cord: A long, thin bundle of nervoustissue that extends from the brain. Makes uppart of the Central Nervous System. Transmitssignals between the brain and the rest of thebody. By itself, it can controlnumerous reflexes.

Work on gluing and coloring your brain!