Chapter 2 - Basic Exercise Science: Nervous System Flashcards
Nervous System
Consists of a network of specialized cells called neurons that transmit and coordinate signals, providing a communication network within the human body
2 Parts of the Nervous System
- CNS
- PNS
4 Primary Functions of the NS
-Sensory Function
-Integrative Function
-Motor Function
Recruitment of muscles, learned patterns of movement, and the functioning of every organ in the human body
Sensory Function
Receive changes in external or internal environment
Sensory Function EXS
- Internal: Stretch placed on muscle
- External: Change from walking on sidewalk to sand
Integrative Function
Process and interpret the sensory information and determine appropriate response
Motor Function
Neuromuscular response to the sensory information
Motor Function EX
Causing a muscle to contract when stretched too far
Proprioception
The body’s ability to sense the relative position of adjacent parts of the body
Efficient Training of NS
Ensures proper movement patterns are being developed which enhances performance and decreases risk of injury
Neuron
Functional unit of the NS
-Specialized cell that processes and transmits information through both electrical and chemical signals
Nerve
Many neurons merged together
3 Main Parts of Neuron
- Cell body (soma)
- Axon
- Dendrites
Cell Body (Soma)
Contains nucleus and other organelles including lysosomes, mitochondria, and Golgi complex
Axon
Cylindrical projection from the cell body that transmits nerve impulses to other neurons or effector sites
-Provides communication from CNS to other parts of the body
Dendrites
Gather info from other structures and transmit it back into the neuron
3 Main Functional Types of Neurons
- Sensory (afferent) neurons
- Interneurons
- Motor (efferent) neurons
Sensory (Afferent) Neurons
Respond to touch, sound, light etc. (changes in external environment) and transmit back to brain and spinal cord
Interneurons
Transmit nerve impulses from one neuron to another in CNS
-process, store, and retrieve information
Motor (Efferent) Neurons
Transmit nerve impulses from the brain and spinal cor to effector sites such as muscles or glands
Central Nervous System
Consists of brain and spinal cord and its primary function is to coordinate the activity of all parts of the body
Peripheral Nervous System
Consists of nerves that connect the CNS to rest of the body and external environment
Nerves of PNS
- 12 Cranial Nerves
- 31 pairs of spinal nerves
- How the CNS receives sensory input and initiates responses
Function of PNS Nerves
- Provide a connection for NS to activate different effector sites
- Relay information from effector sites back to brain via sensory receptors
2 Divisions of PNS
- Somatic NS
- Autonomic NS
Somatic NS
Consists of the nerves that serve the outer areas of the body and skeletal muscle and are largely responsible for the voluntary control of movement
Autonomic NS
Supplies neural input to the involuntary systems of the body (heart, digestive, endocrine)
2 Divisions of Autonomic NS
- Sympathetic
- Parasympathetic
Sympathetic
Increase levels of activation in preparation for activity
Parasympathetic
Decrease levels of activation during rest and recover
Sensory Receptors
Specialized structures located throughout the body that convert environmental stimuli into sensory information that the brain and spinal cord use to produce a response
4 Categories of Sensory Receptors
- Mechanoreceptors
- Nociceptors
- Chemoreceptors
- Photoreceptors
Mechanoreceptors
Respond to mechanical forces (touch, pressure, stretching, sound waves and motion) and transmit impulses through sensory nerves
Nociceptors
Respond to pain
Chemoreceptors
Respond to chemical interaction (smell and taste)
Photoreceptors
Respond to light (vision)
Mechanoreceptors Location
Located in muscles, tendons, ligaments, and joint capsules
Mechanoreceptors Include
Muscle spindles, golgi tendon organs, and joint receptors
Muscle Spindles
Sensory receptors within muscles that run parallel to the muscle fibers and are sensitive to change in muscle length and rate of length change
Muscle Being Stretched
The spindles are also stretched which conveys information about its length to the CNS that can then determine the position of various body parts
Muscle Spindle Being Stretched
Sends an impulse immediately to the spinal cord to contract the muscle
Golgi Tendon Organs
Specialized sensory receptors located at the point where skeletal muscle fibers insert into the tendons of skeletal muscle.
Activation of GTO
Change in muscular tension and rate of tension change
-Will cause the muscle to relax, which prevents the muscle from excessive stress or possibility of injury
Joint Receptors
Located in and around the joint capsule and respond to pressure, acceleration, and deceleration of the joint
-Act to signal extreme joint positions and thus help to prevent injury
Joint Receptor EXS
Ruffini Endings and Pacinian Corpuscles
