Neural influences on exercise Chapter 11

Neuromotor System Organization Central nervous system (CNS) Includes the brain and spinal cord Peripheral nervous system (PNS) Is comprised of cranial and spinal nerves

Frontal Lobe- associated with reasoning, planning, parts of speech, movement, emotions, and problem solving Parietal Lobe- associated with movement, orientation, recognition, perception of stimuli Occipital Lobe- associated with visual processing Temporal Lobe- associated with perception and recognition of auditory stimuli, memory, and speech Frontal Lobe - Front part of the brain; involved in planning, organizing, problem solving, selective attention, personality and a variety of "higher cognitive functions" including behavior and emotions. Click Here for a Diagram of the Frontal Lobe The anterior (front) portion of the frontal lobe is called the prefrontal cortex. It is very important for the "higher cognitive functions" and the determination of the personality. The posterior (back) of the frontal lobe consists of the premotor and motor areas. Nerve cells that produce movement are located in the motor areas. The premotor areas serve to modify movements. The frontal lobe is divided from the parietal lobe by the central culcus. Click Here To Return To Diagram   Occipital Lobe - Region in the back of the brain which processes visual information. Not only is the occipital lobe mainly responsible for visual reception, it also contains association areas that help in the visual recognition of shapes and colors. Damage to this lobe can cause visual deficits. Click Here To Return To Diagram Parietal Lobe - One of the two parietal lobes of the brain located behind the frontal lobe at the top of the brain. Parietal Lobe, Right - Damage to this area can cause visuo-spatial deficits (e.g., the patient may have difficulty finding their way around new, or even familiar, places). Parietal Lobe, Left - Damage to this area may disrupt a patient's ability to understand spoken and/or written language. The parietal lobes contain the primary sensory cortex which controls sensation (touch, pressure). Behind the primary sensory cortex is a large association area that controls fine sensation (judgment of texture, weight, size, shape).Click Here To Return To Diagram Temporal Lobe - There are two temporal lobes, one on each side of the brain located at about the level of the ears. These lobes allow a person to tell one smell from another and one sound from another. They also help in sorting new information and are believed to be responsible for short-term memory. Right Lobe - Mainly involved in visual memory (i.e., memory for pictures and faces). Left Lobe - Mainly involved in verbal memory (i.e., memory for words and names).

Major Neuron Classifications Motor (efferent) neurons Supply extrafusal and intrafusal skeletal muscle fibers Sensory (afferent) neurons Transmit sensory information from peripheral sensory receptors to the brain

Peripheral Nervous System Consists of 31 pairs of spinal nerves (8 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal) and 12 pairs of cranial nerves Look at spinal system PDF Peripheral nervous system

Neurotransmitters of the Brain Neurotransmitters- chemical messengers Synapse= gap between nerves Sensory neurons carry signals from the outer parts of your body (periphery) into the central nervous system. Motor neurons (motoneurons) carry signals from the central nervous system to the outer parts (muscles, skin, glands) of your body. Receptors sense the environment (chemicals, light, sound, touch) and encode this information into electrochemical messages that are transmitted by sensory neurons. Interneurons connect various neurons within the brain and spinal cord.

Neuromuscular junction (closer view) presynaptic terminal sarcolemma synaptic vesicles Acetylcholine receptors mitchondrion

Somatic Nervous System Innervates (voluntary) skeletal muscle Somatic efferent nerve firing excites muscle activation

Autonomic Nervous System (ANS) Innervates smooth muscle (involuntary muscle) in the intestines, sweat and salivary glands, myocardium, and some endocrine glands Has two distinct divisions Sympathetic Parasympathetic

Sympathetic Nervous System Sympathetic neurons Exit the spinal cord and enter a series of ganglia (sympathetic chain) near the cord Release norepinephrine Activated during flight-or-fight situations Accelerates breathing and heart rate Dilates pupils Helps redistribute blood flow from the skin to deeper tissues in anticipation of a perceived challenge

Parasympathetic Nervous System Parasympathetic nerve neurons Release acetylcholine (cholinergic fibers) Produce effects opposite of sympathetic fibers

Reflexes Autonomic reflex arc Complex reflexes Learned reflexes Monosynaptic reflex arc Polysynaptic reflex arc Complex reflexes Crossed-extensor reflex Learned reflexes Reflexes

Reflexes Sensory input Transmission of afferent impulses to spinal cord via sensory root Causes muscle fibres to contract

Complex reflexes 1- tack stimulates pain receptors in the skin 2- goes up sensory neurons  grey matter in brain 3- motoneurons synapse- flexor and extensor muscles 4- stimulation of contraction and relaxation in appropriate muscles- flex in hamstrrings, extension quads Once those nerve pathways have been excited in the same way over and over, they get better at doing the same things

Sports reflexes What happens in each of the players to enable them to catch the ball??

Muscle fibre types

All-or-None Principle If a stimulus triggers an action potential in the motoneuron, all of the accompanying muscle fibers contract synchronously A single motor unit cannot generate strong and weak contractions—either the impulse elicits a contraction or it does not

Lab manuals Must be to me by Friday Or 10% penalty per day My office 3.11 Or 10% penalty per day Special consideration

Prac break 3 weeks 2nd year prac 1 week mid semester break