KINS 4070 test 2

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