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What is the endocrine system responsible for?
hormones
What are the three effects that a hormone can have at a tissue?
altering cell membrane transport, stimulate new protein synthesis, and second messenger systems
Altering cell membrane transport
if the body notices it needs more of something, it will alter the cell membrane in order to make more of what it needs
Stimulate new protein synthesis
when a hormone binds to a receptor, it can change into a new protein
Second messenger systems
secondary set of chemical reactions inside the cell
What are the three mechanisms that allow for controlling the magnitude of endocrine-controlled response?
More hormone secreted, more receptors, and increasing the attraction of a receptor
The hypothalamus (godfather)
releases hormones to stimuate the anterior pituitary
As exercise intensity increses…
the more depletion of glycogen stores
Why is blood glucose regulation so important?
neurons cannot use fats for energy, so they must have sufficient carbohydrate supply
What are the four endocrine-controlled mechanisms for keeping blood glucose levels up during exercise
glycogenolysis, gluconeogenesis, lipolysis, block glucose uptake
Permissive/slow acting hormones
thyroxine, cortisol, and growth hormone
fast-acting hormones
epinephrine, norepinephrine, insulin, glucagon
movement
memory and learning
analysis and problem solving
emotional responses
homeostasis
roles of the nervous system
Central nervous system
brain and spinal cord
peripheral nervous system
carries information to and from the CNS, afferent and efferent
Afferent (sensory)
carries information to the brain
Efferent (motor)
sends information out, somatic and autonomic
Somatic
voluntary output to muscles
Autonomic
involuntary signals go to effectors
Sympathetic nervous system
revs things up
parasympathetic nervous system
calms things down
What system is the exception to the sympathetic and parasympathetic?
digestive
What are the three main components of a neuron?
soma, dendrites, axons
What is the role of a neuron?
send messages to other neurons
Soma (body)
contains nucleus
dendrites
gather information
axons
send messages from the cell
Schwann cells
PNS cells with myelin sheath coating
Nodes of ranvier
Space between Schwann cells were the axon is exposed
What are the three types of neurons?
Sensory, interneurons, motor
What kind of neuron is typically unipolar?
sensory
What kinds of neurons are typically multipolar?
interneurons and motor neurons
resting potential (-70mV)
negative charge/polarized
starts out at negative charge
more EPSPs than IPSPs cause it to hit threshold
sodium gate opens up, allowing sodium to rush into the cell (depolarization)
postassium gate opens up, potassium rushes out of the cell (repolarization)
how an action potential is generated
Saltatory conduction
nerve impulses move quickly down a myelinated axon at the nodes of ranvier
How does a neuron reset after an action potential?
The sodium potassium pump pushes sodium back out of the cell and pulls potassium back into the cell to get the gradient back.
What is a motor unit?
one motor neuron and all the fibers it innervates
What is a reflex?
a preprogrammed response to a stimulus
What role do the cortical and subcortical areas play in voluntary movement?
sends “rough draft” of the movement
What role do the cerebellum and basal ganglia play in voluntary movement?
convert the rough draft into an actual plan
The cerebellum is responsible for ___ movements.
fast
The basal ganglia is responsible for ___ , more deliberate movements.
slower
What role does the motor cortex play in voluntary movement?
pulls the trigger and sends the message down the spinal cord
What role does the spinal cord play in voluntary movement?
does the fine tuning to carry out the exact movement
What are muscle spindles?
receptors that give information about the changing length of a muscle
What are golgi tendon organs
gives information about the tension on a muscle
Proprioceptors
muscle spindles and golgi tendon organ
Primary parasympathetic neurotransmitter
acetylcholine
Primary sympathetic neurotransmitter
norepinephrine
Layer of tissue that surrounds the entire muscle
epimysium
Bundle of muscle fibers is called…
fascicle
Sarcolemma
plasma membrane of a muscle fiber
Opens from the sarcolemma and goes down through the muscle fiber
transverse tubules
One t-tubule and two ____ are found together, aka lateral sacks
terminal cisternae
One z-line to the next
sarcomere
Perimysium
sheath surrounding a fascicle
endomysium
surrounds each muscle fiber
Tropomyosin
filaments that wrap around actin
Troponin
protein that binds to tropomyosin
Neuromuscular junction
synaptic connection between the terminal end of a motor nerve and a muscle
All or none law
When a motor neuron receives an action potential, all of the surrounding fibers will twitch
What are the two ways muscles exert different amounts of tension?
Recruitment and summation
Recruitment
The ability to fire only certain nerurons to control the amount of tension a muscle produces
Summation
Tension from a twitch building off one another before the previous one has completely relaxed
Type 1 fibers are also known as…
slow twitch
Type IIx fibers are also known as…
fast twitch
lots of mitochondria
hard to fatigue
best for endurance
ST fibers
low in mitochondria
glycolysis (fatiguing)
best for quick/explosive movement
FT fibers
Isometric contraction
muscle contracts without changing length
Isotonic contraction
muscle shortens and lengthens as is contracts
concentric contraction
muscle stimulated and shortens
eccentric contraction
muscle lengthens with tension
Length-tension relationship
The amount of tension a muscle can produce at a given length
Generally, the longer the longer the muscle is, the ___ tension it can produce.
less
At what length can a muscle produce the most tension?
in the middle
Force-velocity relationship
As the muscle takes on higher loads, the ability to move it with greater velocity decreases
What does lactic acid release that causes fatigue?
hydrogen ions
Why do hydrogen ions cause fatigue?
They bind to troponin which prevents calcium from binding which does shift the tropomyosin.
Hypertrophy
increase in the size of a cell resulting in bigger muscles
Atrophy
cells decrease in size, losing muscle
sarcopenia
age related loss in muscle mass
The effect a hormone exerts on a tissue is directly related to…
the concentration of the hormone in the plasma and the number of receptors available
What hormone is involved in homeostatic control of calcium levels?
parathyroid hormone
Catecholamines are secreted from the ____.
adrenal medulla
Examples of fact-acting hormones responsible for the maintenance of plasma glucose are ___ and ___.
epinephrine and norepinephrine
Which hormone is secreted by the alpha cells of the islets of Langerhans?
glucagon
The maintenance of plasma glucose during exercise can be accomplished by…
liver glycogenolysis, mobilization of FFA, and liver gluconeogenesis
The discontinuous sheath that covers the axon of a motor neuron is made up of…
Schwann cells
Neurotransmitters that cause depolarization of membranes are called…
excitatory transmitters
When threshold potential is reached, the neuron depolarizes due to…
rush of sodium into the cell
The area of the brain which refines a complicated or rapid response motor plan based on the feedback from the various receptors is the…
cerebellum
The maintenance of the body's internal environment is carried out by the…
autonomic nervous system
The area of the muscle fiber which is initially stimulated by the motor neuron is called the…
motor end plate
When the fiber is stimulated, calcium is released from the…
terminal cisternae
The amount of force generated by a group of muscles depends on…
type and number of fibers recruited, initial length of muscle, repetition of neural stimulation
Type IIx fibers have limited capacity for…
aerobic metabolism
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