Brain and Nervous

System CLICK ON YOUR SPACE BAR OR MOUSE TO MOVE THROUGH THIS POWERPOINT!

QUESTION

What is a NEURON?

ANSWER

A neuron is a nerve cell that is the basic building block of the nervous system.

highly specialized nerve cells are responsible for communicating information in both chemical and electrical forms.

Question How many parts does a neuron

have?

ANSWER

Three

Question

What are the 3 parts of a NEURON?

And the Answer Is…

Cell BodyAxonDendrites

QUESTION

What does a Cell Body do?

ANSWER

Each neuron cell body is a center for receiving and sending nerve impulses. Cell body also makes proteins.

QUESTION

What does an AXON DO?

ANSWER!

Carries messages. A tube like structure

QUESTION

What is the function of dendrites and Axons?

The difference between Dendrites and Axons Of a Neuron are?

Axons Take information away from the cell body Smooth Surface Generally only 1 axon per cell No ribosomes Can have myelin Branch further from the cell body Dendrites Bring information to the cell body Rough Surface (dendritic spines) Usually many dendrites per cell Have ribosomes No myelin insulation Branch near the cell body

QUESTION

What is the resting potential?

ANSWER

When a neuron is NOT sending a signal it is at “REST.”

When at rest the inside of the neuron is – neg charged.

At rest potassium K+ can cross through the membrane easily.

At rest (CL-) chloride and sodium (NA+) have a more difficult time passing. At rest there are more?

sodium ions on the outside of the neuron and less potassium on the inside.

QUESTION?

What Is Action Potential? Also know as a Nerve impulse.

ANSWER

Action potential occurs when a neuron send information down an axon, AWAY from the CELL BODY!

The Action potential is an explosion o9f electrical activity.

That is created by depolarizing current.

QUESTION

Explain the mechanism for action potential

ANSWER

Action potentials are caused by an exchange of ions across the neuron membrane. A stimulus first causes sodium channels to open. Because there are many more sodium ions on the outside, and the inside of the neuron is negative relative to the outside, sodium ions rush into the neuron. Remember, sodium has a positive charge, so the neuron becomes more positive and becomes depolarized. It takes longer for potassium channels to open. When they do open, potassium rushes out of the cell, reversing the depolarization. Also at about this time, sodium channels start to close.

QUESTION

What is the refractory period?

Answer

is a period of time during which an organ or cell is incapable of repeating a particular action, or (more precisely) the amount of time it takes for an excitable membrane to be ready for a second stimulus once it returns to its resting state following an excitation. It most commonly refers to electrically excitable muscle cells or

neurons.

QUESTION

Transmission of nerve impulse from one neuron to another happens how?

Answer

1. Polarization of the neuron's membrane: Sodium is on the outside, and potassium is on the inside.

2. Resting potential gives the neuron a break. 3. Action potential: Sodium ions move inside the

membrane. 4. Repolarization: Potassium ions move outside,

and sodium ions stay inside the membrane. 5. Hyperpolarization: More potassium ions are on

the outside than there are sodium ions on the inside. 6. Refractory period puts everything back to normal:

Potassium returns inside, sodium returns outside.

Question

What are the parts of a synapse?

ANSWER

1. a presynaptic ending that contains neurotransmitters, mitochondria and other cell organelles,2. a postsynaptic ending that contains receptor sites for neurotransmitters and,3. a synaptic cleft or space between the presynaptic and postsynaptic endings.

QUESTION

What are the different types of neurogleal cells?

Answer

Astrocytes Oligodendrocytes Ependymal cells Schwann cells Satellite cells

What do they do?

The most abundant type of macroglial cell, astrocytes (also called astroglia) have numerous projections that anchor neurons to their blood supply. They regulate the external chemical environment of neurons by removing excess ions, notably potassium, and recycling neurotransmitters released during synaptic transmission.

Oligodendrocytes are cells that coat axons in the central nervous system (CNS) with their cell membrane forming a specialized membrane differenciation called myelin, producing the so-called myelin sheath. The myelin sheath provides insulation to the axon that allows electrical signals to propagate more efficiently.

Ependymal cells, also named ependymocytes, line the cavities of the CNS and make up the walls of the ventricles. These cells create and secrete cerebrospinal fluid(CSF) and beat their cilia to help circulate that CSF.

Continued

Similar in function to oligodendrocytes, Schwann cells provide myelination to axons in the peripheral nervous system (PNS). They also have phagocytotic activity and clear cellular debris that allows for regrowth of PNS neurons.

Satellite cells are small cells that line the exterior surface of PNS neurons and help regulate the external chemical environment.

What Comprises the CNF? The BRAIN and the SPINAL CORD

Question

What Is Broca’s Area and what does it

do????? Hmmmmm

The Answer Is…

Brocas Area is Involved in language processing, speech or sign production, and comprehension.

Question For ya

What nerve is affected by Bellas Palsy?

ANSWER IS~~~

THE FACIAL NERVE Of Course

Question

What are the components of a reflex arc?

ANSWER

RELEX ARC CoNSISTs OF 5 MAIN PARTS

Sensory neuron CNS integration center And effector {Think Scammer}

(scamr) Motor neuron Receptor

To remember that these relate to the reflex arc think scammers arc you…..lol

CONTINUED

Step 1) Heat ( a stimulus)Step 2) Pain receptor stimulatedStep 3) Signal passed along sensory

neuronStep 4) Signal passed to relay neuronStep 5) Signal passed to motor neuronStep 6) Signal passed to muscle for

response ( move hand away from fire)

Question

What type of reflex would a knee jerk be?

ANSWER IS>>>

Stretch reflex of course……because there is only one synapse in the circuit needed to complete the reflex. A stretch reflex is a muscle contraction in response to stretching within the muscle. It is a monosynaptic reflex which provides automatic regulation of skeletal muscle length.

Label The Neuron

ANSWER

Question

What are the general affects of sympathetic stimulation?

ANSWER

dilates pupil increases heart rate dilates air passages in lung reduces gut motility increases blood glucose level reduced urine output sweating shunting of blood to vital organs (skin turns pale, blood to

gut is cut off, blood only goes to brain, heart, necessary muscles)

piloerector muscles (raise hair and goosebumps) FIGHT OR FLIGHT REACTION….Think Sympathy for those

in a bad situation where they have to feel fight or flight.

Question

Explain the parasympathetic nervous system…..

AnSwEr

part of the autonomic nervous system which usually prepares the organism to deal more effectively with a situation of peace, rest, and recovery.