Chapter 1 and 2: Introduction and Nervous System Flashcards
What is kinesiology?
The study of human movement and mechanics
Which 2 functions of the nervous system are most important to strength and conditioning?
Processing sensory input
Coordinating movement
What’s involved with coordinating movements and processing sensory input?
1) Planning, initiating, and controlling movements
2) Smell, vision, taste, hearing
Receipt and interpretation of somatosensory information from the joints, ligaments, muscles, and skin
What are the two main types of CNS cells?
Neurons and glia
What are the neurons responsible for?
- Transmitting electrical impulses throughout the body
- Producing an action potential
What is an action potential?
A rapid and substantial depolarization of the neuron’s membrane
What are the 4 main types of neurons?
Motor neurons: Transmit commands from the brain or spinal cord to muscles and glands (i.e. fine and gross motor skills)
Sensory neurons: Transmit information into the brain and spinal cord to detect movement, sight, touch, sound, and smell
Interneurons: Create circuits between sensory or motor neurons, and transmit information between different parts of the brain (i.e. internet of the brain)
Dendrites: Branches of the cell body that act as receivers, collecting information from other neurons.
What does glia provide?
protection and nutrients to neurons
-Example: Myelin forms a fatty sheath around the axon of a nerve
What connects a motor neuron to a muscle or gland and releases acetylcholine when innervating a muscle?
A synapse
How does acetylcholine work?
Binds to receptors on the muscle that trigger contraction after being released from the parasympathetic nervous system
What are the following part of? Motor division, Sensory division, Somatic nervous system, Autonomic nervous system
The peripheral nervous system
What are the parts of the autonomic nervous system?
The sympathetic nervous system
The parasympathetic nervous system
What does the autonomic nervous system control?
Subconscious actions such as breathing, heart rate, and digestion
What does the somatic nervous system control?
Voluntary movement
Where does the sensory division of the PNS send information from and to?
From the organs to the CNS
What does the motor division stimulate? Where does it carry nerve impulses from?
Muscles and glands
The central nervous system
What are the main parts of the spinal cord?
- Meninges
- Cerebrospinal fluid
- Ventricles
- Sensory Nerve
- Motor Nerve
- Mixed Nerve
What type of information do spinal nerves relay?
Motor, sensory, and autonomic
Where do motor neurons reside?
The peripheral nervous system
What are the three motor units and three primary muscle fiber types?
- Slow (S) motor unit = type I muscle fibers that can contract for hours
- Fast fatigue-resistant (FFR) motor unit = type IIa muscle fibers can contract for minutes
- Fast fatigable (FF) motor unit = type IIx muscle fibers last for 5-10 seconds
What two neural processes determine the amount of force a muscle produces?
Motor unit recruitment: the activation of additional motor units for the muscle to produce higher levels of force
Rate coding. The frequency a motor neuron sends an action potential to its bundle of muscle fibers. The higher the rating coding, the stronger the contraction.
What is the size principle of motor neuron recruitment?
The fixed, orderly recruitment of motor neurons from smallest to largest. Every movement uses S motor units, but only movements that require higher levels of force recruit FFR and FF motor units.
Low force = S motor units
Medium force = S + FFR motor units
High force = S + FFR + FF motor units
Small motor neurons are recruited first because they have a low threshold for activation.
FFR motor units have medium-size motor neurons and require more neural input from the spinal cord to activate.
FF motor units have the largest motor neurons and require very high levels of neural input to activate.
Where does voluntary movement happen?
The motor cortex
What are the parts of the motor cortex?
- Premotor cortex
- Primary motor cortex
- Supplementary motor area
How does the motor cortex communicate with the lower motor neurons?
Via neural tracts
What is required for a joint to move?
The agonist (primary) muscle must be activated while the antagonist is inhibited.
What does the GTO do?
The Golgi tendon organ detects changes in muscle tension and sends a signal to the spinal cord.
What is alpha-gamma co-activation?
A process of muscle and muscle spindles contracting at the same rate.
What part of forebrain help the CNS learn and control movement?
Cerebrum
What parts of brain stem help the CNS interpret and analyze information?
The midbrain, pons, and medulla
What part of the brain helps the CNS plan and coordinate movement?
Cerebrum
What is responsible for transmitting motor information down from the brain and sensory information up to the brain?
The spinal cord
What do upper motor neurons synapse with?
Lower motor neurons
What does the muscle spindle do when a muscle lengthens rapidly?
It sends a distress signal into the spinal cord to avoid this potentially injurious action
What does the diencephalon do?
Part of the forebrain that relays and integrates information from different parts of the brain and spinal cord
What are the two different kinds of neural tracts?
- Descending tracts send motor information down toward the muscle
- Ascending tracts send sensory information from muscles and joints through the spinal cord to the brain
What system releases norepinephrine to generate the fight or flight response?
The sympathetic nervous system
What system handles the rest and digest physiological processes?
The parasympathetic nervous system
What innervates muscles or glands and carries information that leads to muscle contraction?
A lower motor unit
The pons, midbrain, and medulla have sensory and control of which muscles?
Head, neck, face, balance
