The Nervous System and the Control of Movement “He’s Got what you might call a control problem. The guy has a million dollar arm, but only a ten cent brain.” --From Bull Durham (1988)
Nervous System We have now seen how muscle contraction/movement occurs and how the body creates energy to sustain movement. But what initiates the movement? The Nervous system is the body’s system which is responsible for gathering information, storing it, and responding to it. Its main objective is gather internal and external information, analyze that information and initiate certain responses to satisfy certain needs.
Pass it on….. 2 teams, everyone holds hands Last person of each team holds a stop watch When I say “GO” I will send out a signal to each team, it will travel around the circle and once it reaches the last person you must stop the stop watch Switch up the last person of each team
Spinal cord
The Components of the Nervous System Central Nervous System (CNS) Peripheral Nervous System (PNS)
Overview….
(A) Central Nervous System Composed of two parts: The Brain The Spinal Cord
Parts of the skull
Brain Frontal lobe: higher order thought, and initiation of movement Parietal lobe: somatosensation (pain, temperature, and touch sensation from the body) Temporal lobe: processes auditory, olfactory (smell), and gustatory (taste) information Occipital lobe: processes visual information Cerebellum: refines and coordinates movement
The Brain… Cerebrum Cerebellum Brain Stem Diencephalon Limbic System Reticular activating system
Spinal Cord
Spinal Cord Dorsal View 13
Cerebrum…Largest part of the brain! Contains nerve centres that control sensory motor activities as well as intelligence Divided down the middle into two halves (Cerebral Hemispheres) Each hemisphere is divided into four lobes named after the cranial bones which protect that area of the brain
Cerebellum…The Second largest part of the brain! Lies behind and below the cerebrum Main function is to co-ordinate muscle movement and control balance
The Brain Stem Located below the cerebrum and in front of the cerebellum Links the cerebrum with the spinal cord Responsible for autonomic functions, posture, muscle tone, and eye movement
The Diencephalon Consists of the Thalamus and the Hypothalamus Located b/w the cerebrum and the brain stem Thalamus relays sensory info Hypothalamus controls things such as body temperature, appetite, emotions and other autonomic functions
Other components The Limbic system is responsible for regulating emotions, and hunger The reticular activating system is responsible for sending sensory information to the appropriate centres for interpretation. Also it is crucial for maintaining consciousness.
Spinal Cord Second major component of the CNS Main pathway for information connecting the brain and the peripheral nervous system Runs through the vertebral column Spinal nerves branch off of the spinal cord, b/w vertebra, allowing nerves to travel to tissues and organs Cervical nerves are named according to where they branch away from the vertebrae. Eg. C6---deltoid, L3,4---quads
When Things go wrong!
(B) Peripheral Nervous System The PNS consists of those parts of the nervous system that lie outside of the Brain and spinal cord Massive road network carrying information to and from the CNS Consists of 12 pairs of cranial nerves that emerge from the brain, and 31 pairs of spinal nerves that leave the spinal cord at various parts of the body Each pair of nerves contain one motor nerve (efferent nerves) and one sensory nerve (afferent nerves). Afferent---CNS Efferent---muscles/organs
Overview revisited….
Peripheral Nervous System Autonomic Nervous System Involuntary contraction of cardiac muscle and smooth muscle cells -sympathetic system prepares body for emergencies, and turns things on. Release of adrenaline -parasympathetic system brings the body back to normal after being stimulated by the sympathetic system Somatic Nervous System Involves the awareness of our environment and the subsequent muscular activity to cope with that situation. Involves afferent nerves sending information to the CNS, and efferent nerves sending a stimulus to muscles. E.g. Page 97 in text…..shows how this system works together with the autonomic system
Sensory and Motor Neurons
Questions Draw a mind map/concept map of the Nervous system. Include a brief description of each component Outline the reflex arc. What is it? and what are the five parts? What are proprioceptors? Compare and contrast GTO and Muscle Spindles What is the stretch reflex? What is reciprocal inhibition? What is the crossed extensor reflex?