1. Nervous System and The Brain

4. The Nervous System Subdivided into two categories:
Central Nervous System
Contains brain and spinal cord
Peripheral Nervous System
Nerves and ganglia outside of CNS
Reflexes
A hot stove

8. The Nervous System
The nervous system has a coordinating role where it receives, processes, stores, and transmits information that comes from the body and the outside world
The neuron is the basic unit (cell) of the nervous system
Impulses (signals) are carried throught the body by nerves

9. Neurons Dendrite receives impulses Axon propagates the impulses
Longest neuron in the body? Sciatic nerve which connects toes to spinal cord

10. Neurons The neurons are the only cells that react to a stimulus
A stimulus is a change in the environment that results in nerve excitation
Ex. sun shining in your eyes or hearing a sound
Nerves are structures that help transmit information between the central nervous system and the various regions of the body

12. Transmitting Signals
Neurons must pick up stimuli, transform them into nerve impulses and then transmit these impulses on to the next neuron
A nerve impulse is therefore any electric signal transmitted by a neuron
As signals move from one neuron to another, they must cross the synapse. This is the transition zone between two neurons (a very small gap)

13. Basic Tasks of the Nervous System
Sensory Input: Monitor both external and internal environments.
Integration: Process the information and often integrate it with stored information.
Motor output: If necessary, signal effector organs to make an appropriate response.

15. Nervous System Composed of CNS and PNS
The central nervous system is made of the brain and the spinal cord

16. The Brain Some brain myths…

21. The Brain The brain controls everything in the body
The brain contains more than 100 billion neurons (nerve cells) and is the biggest part of the central nervous system

22. Size isn’t everything…
Neanderthal brains had more capacity devoted to vision and body control, with less left over for social interactions and complex cognition
Morton – racist brain size study
nature/science-shows-why-youre-smarter-than-a- neanderthal /

23. Parts of the Brain The Brain has three main parts… Cerebrum Cerebellum
Medulla oblongata (brain stem)

24. Concussions https://www.youtube.com/watch?v=tgChTeALF7g
Fencing response

25. The Cerebrum The largest part of the brain It controls your: Thinking
Memory
Speaking
Movement
Identifies info gathered by your sensory organs

26. Lobes of the Brain
The cerebrum is divided into several lobes, each of which is responsible for different tasks
The frontal lobes are responsible for problem solving and judgment and motor function.

27. Lobes of the Brain
The parietal lobes manage sensation, handwriting, and body position.
The temporal lobes are involved with memory and hearing
(short + long term)
The occipital lobes contain the brain's visual processing system.
(eyes + nostril ex)

28. The Cerebellum Below and to the back of the cerebrum.
Controls your balance and posture
(along with inner ear)

29. Medulla Oblongata (Brain Stem)
Connects the brain to the spinal cord
Controls heartbeat, breathing and blood pressure
Responsible for certain reflexes: coughing, swallowing, hiccups, vomiting, and sneezing

30. Grey vs White Matter
The brain can be divided into two types of tissue

31. Grey Matter
The part of the brain controlled by nerve cell bodies and dendrites.
It is grey in appearance and is where the true processing occurs
Makes up 40% of the human brain and requires 94% of available oxygen

32. White Matter Composed of axons
Found in the center of the brain and between the brain stem and cerebellum
Facilitates communication between the grey matter of the brain and between the brain and the rest of the body
Makes up 60% of the human brain

33. Spinal Cord Connects the brain to the rest of the nervous system.
Sends messages to and from the brain.
The spinal cord is protected by small bones called vertebrae

34. Vertebrae

35. Peripheral Nervous System (PNS)
Consists of all the nerves that leave the spinal cord or brain reaching all parts of the body.
It has 2 types of nerves
Sensory nerves – sending info to CNS
Motor nerves – sending info to muscles

36. Types of Action PNS has 3 types of actions: Voluntary acts
Involuntary acts
Reflexes

37. Voluntary Acts This system contains the skeletal muscles
Responsible for the conscious control of our movement
Signals from the brain effectuate contractions of the muscles

38. Involuntary Acts
An action that occurs without conscious thought or choice
Breathing, hiccups, digestion, coughing, sneezing

39. Reflex https://www.youtube.com/watch?v=qpw31bvoLpg
Is an involuntary automatic reaction that happens without thinking about it, due to an external stimulus
A reflex happens quickly in less than a second.
The difference between a reflex and an involuntary action is that a reflex requires a stimulus (external factor)

40. Reflex Arc

41. The brain is not involved in a reflex.
Sensory Receptor
(responds to a stimulus by
producing a impulse)
Sensory Neuron
(axon conducts impulse)
Integrating Center
(Relay impulse from
sensory to motor neurons)
Motor Neuron
(axon conducts impulse
to effector)
Effector
(muscle that responds to
A motor nerve impulse)