The Nervous System& the control of movement

The Nervous System& the control of movement

Chapter 6Chapter 6

Q: What is the main role of the Nervous System?

Q: What is the main role of the Nervous System?

A: To “assemble info about conditions external & internal to the body, to analyze this information and initiate an appropriate response”.

“COMMUNICATION NETWORK”

A: To “assemble info about conditions external & internal to the body, to analyze this information and initiate an appropriate response”.

“COMMUNICATION NETWORK”

The Nervous System

1. cerebrum2. cerebellum

3. brain stem 4. diencephalon5.limbic system 6.reticular activating system

Brain Spinal Cord

The Central Nervous System(CNS)

Sympathetic"Fight or Flight"

Parasympathetic"Homeostasis"

Autonomic Nervous System(involuntary)

Somatic Nervous System(voluntary)

12 Cranial Nerves31 pairs of Spinal Nerves

The Peripheral Nervous System(PNS)

The Nervous System

The body's "Communication System"

What are the 2 Major Components of the Nervous System?

What are the 2 Major Components of the Nervous System?

1. The Central Nervous System

2. The Peripheral Nervous System

1. The Central Nervous System

2. The Peripheral Nervous System

CNS (Central Nervous System)

CNS (Central Nervous System)

Two Parts:A) The Brain

B) The Spinal Cord (& vertebral column)

Two Parts:A) The Brain

B) The Spinal Cord (& vertebral column)

CNS ‘A’ - The BrainCNS ‘A’ - The Brain

Main control center for survival Emotions

The brain is made up of 6 parts:

Main control center for survival Emotions

The brain is made up of 6 parts:

The 6 Brain SegmentsThe 6 Brain Segments

1) Cerebrum:

-largest section-controls sensory, motor &

intelligence functions-2 hemispheres / 8 ‘lobes’

1) Cerebrum:

-largest section-controls sensory, motor &

intelligence functions-2 hemispheres / 8 ‘lobes’

The 6 Brain Segments (continued)The 6 Brain Segments (continued)

2) Cerebellum - coordinates balance & muscle movement

3) Brain Stem - links cerebrum to the spinal cord

---> Autonomic functions like “muscle tone”

2) Cerebellum - coordinates balance & muscle movement

3) Brain Stem - links cerebrum to the spinal cord

---> Autonomic functions like “muscle tone”

The 6 Brain Segments (continued)The 6 Brain Segments (continued)

4. Diencephalon-divided into the:4. Diencephalon-divided into the:

i) Thalemus-pain & attention

ii) Hypothalemus-appetite-emotions-body temperature

The 6 Brain Segments (continued)The 6 Brain Segments (continued)

5. Limbic System:-regulates basic drives like hunger,

emotions, aggression

6. Reticular Activating System-crucial for maintaining

consciousness

5. Limbic System:-regulates basic drives like hunger,

emotions, aggression

6. Reticular Activating System-crucial for maintaining

consciousness

CNS ‘B’ - Spinal Cord(& Vertebral Column)

CNS ‘B’ - Spinal Cord(& Vertebral Column)

Main info pathway between brain & PNS

Spinal Cord - 45cm (brain stem to L2)

Spinal Nerves carry:-sensory info to CNS & -motor commands away from CNS

Main info pathway between brain & PNS

Spinal Cord - 45cm (brain stem to L2)

Spinal Nerves carry:-sensory info to CNS & -motor commands away from CNS

What are the 2 Major Components of the Nervous System?

What are the 2 Major Components of the Nervous System?

1. The Central Nervous System

2. The Peripheral Nervous System

1. The Central Nervous System

2. The Peripheral Nervous System

PNS (Peripheral Nervous System)PNS (Peripheral Nervous System)

12 Cranial Nerves / 31 Spinal Nerves (sensory fibers)

Responsible for voluntary actions & bodily functions

Eg heart beat, muscle control Made of Autonomic NS & Somatic NS Efferent nerves (motor) - carry info from

CNS to organs (Efferent-->muscles) Afferent nerves (sensory)- carry info to

brain --> Afferent-->brain)

12 Cranial Nerves / 31 Spinal Nerves (sensory fibers)

Responsible for voluntary actions & bodily functions

Eg heart beat, muscle control Made of Autonomic NS & Somatic NS Efferent nerves (motor) - carry info from

CNS to organs (Efferent-->muscles) Afferent nerves (sensory)- carry info to

brain --> Afferent-->brain)

PNS ‘A’- Autonomic Nervous System

PNS ‘A’- Autonomic Nervous System

Involuntaryi) Sympathetic System:

-prepares body for emergencies(fight or flight response)

ii) Parasympathetic System:-returns boy to normal after

‘emergency’

Involuntaryi) Sympathetic System:

-prepares body for emergencies(fight or flight response)

ii) Parasympathetic System:-returns boy to normal after

‘emergency’

PNS ‘B’- Somatic Nervous System

PNS ‘B’- Somatic Nervous System

Components:-afferent & efferent nerve fibers-PNS controls and knows what our

muscles/tendons are doing & feeling

(ie pain, cold, balance, etc.)

Components:-afferent & efferent nerve fibers-PNS controls and knows what our

muscles/tendons are doing & feeling

(ie pain, cold, balance, etc.)

REFLEX ARCREFLEX ARC

-Automatic response to stimulation-if command center for the flex is: a)the brain ---> cerebral reflex arc

b)the spinal cord --->spinal reflex arc

-Automatic response to stimulation-if command center for the flex is: a)the brain ---> cerebral reflex arc

b)the spinal cord --->spinal reflex arc

Autonomic ReflexesAutonomic Reflexes

-some involve smooth muscle, cardiac muscle, glands

-regulates digestion, blood pressure, sweating

-some involve smooth muscle, cardiac muscle, glands

-regulates digestion, blood pressure, sweating

Somatic ReflexesSomatic Reflexes

-involve stimulation of skeletal muscle

ie -stretch reflex, withdrawl reflex

-involve stimulation of skeletal muscle

ie -stretch reflex, withdrawl reflex

Basic Reflex ArcBasic Reflex Arc

The components of a basic reflex include;i) receptorii) adjustoriii) effector

The components of a basic reflex include;i) receptorii) adjustoriii) effector

Reflex ArcReflex ArcThe components of a reflex arc include;

i) receptorii) sensory or AFFERENT nerve (brain)iii) intermediate nerve fibers (adjustor) which interprets the signal & issues an appropriate responseiii) motor or Efferent nerve (muscle)v) effector organ (muscle)

-if command center for the flex is: a)the brain ---> cerebral reflex arc

b)the spinal cord --->spinal reflex arc

The components of a reflex arc include;i) receptorii) sensory or AFFERENT nerve (brain)iii) intermediate nerve fibers (adjustor) which interprets the signal & issues an appropriate responseiii) motor or Efferent nerve (muscle)v) effector organ (muscle)

-if command center for the flex is: a)the brain ---> cerebral reflex arc

b)the spinal cord --->spinal reflex arc

ProprioceptorsProprioceptors

Provide info re:- muscle contraction- position of limbs- body posture- balance

Provide info re:- muscle contraction- position of limbs- body posture- balance

ProprioceptorsProprioceptors

There are 2 receptors:

i) Golgi Tendon Organs (GTO)

ii) Muscle Spindles

There are 2 receptors:

i) Golgi Tendon Organs (GTO)

ii) Muscle Spindles

Golgi Tendon OrgansGolgi Tendon Organs

- tension detectors- In the tendon of the muscle

- Tension Reflex: GTO, Afferent Neuron, CNS, Efferent Neuron, Motor unit

- tension detectors- In the tendon of the muscle

- Tension Reflex: GTO, Afferent Neuron, CNS, Efferent Neuron, Motor unit

Muscle SpindlesMuscle Spindles

-senses changes in muscle length-2 afferent neurons & 1 efferent

neuron-very sensitive

“Stretch Reflex”(see table 6.1 on pg. 101 in text)

-senses changes in muscle length-2 afferent neurons & 1 efferent

neuron-very sensitive

“Stretch Reflex”(see table 6.1 on pg. 101 in text)