Unit 2

cns/central nervous system

the ____ is made up of the brain and spinal cord

pns/peripheral nervous system

the ____ is made up of everything outside of the brain and spinal cord

afferent

these type of neurons carry information from receptors to the brain and spinal cord

somatic sensory

this afferent pathway signals from touch, pain, temperature and any other conscious perception

visceral sensory

this afferent pathway carries information from the internal organs that is not consciously perceived

efferent

these type of neurons carry information from the CNS to an effector organ

somatic motor

which division of the motor nervous system is responsible for voluntary control, and targets skeletal muscle?

autonomic motor

Which division of the motor nervous system handles involuntary control, and targets smooth and cardiac muscle and glands?

sympathetic

does the sympathetic or parasympathetic system increase with activity?

parasympathetic

does the sympathetic or parasympathetic system decrease with activity?

sympathetic

which division of the autonomic nervous system releases NE by the postganglionic neuron?

parasympathetic

which division of the autonomic nervous system releases Ach by the postganglionic neuron?

cerebrum

what part of the brain is in charge of receiving sensory information and organizing complex movement?

cerebellum

what part of the brain is in charge of coordination and feedback?

brainstem

what part of the brain is in charge of cardiovascular and respiratory control, metabolic functions, complex reflexes and maintaining postural tone?

spinal cord

what part of the CNS is in charge of refining movement?

spinal tuning

where the spinal cord translates a voluntary movement command from the brain into an appropriate muscle action using spinal neuronal networks

withdrawal reflex

this reflex pulls the limb away from a painful stimulus

cross-extensor reflex

this reflex happens when the muscles on the opposite side contract to help maintain balance after painful stimulus

muscle chemoreceptors

detect chemical changes around muscle fibers such as increase in H+, K+, Pi, and lactate

ATP + H2O → ADP + Pi + H+ + energy

write out the equation for ATP hydrolysis

metaboreflex

An automatic body response that redirects blood flow to vital organs and breathing muscles when working muscles become tired and lack oxygen

metabolites

an increase in ______ causes the metaboreflex

mechanical

mechanoreceptors detect a _______ change and they respond to changes in muscle length, pressure, force, tension

metaboreflex + mechanoreflex

the exercise pressor reflex is made up of:

exercise pressor reflex

• Helps to regulate the cardiovascular and respiratory systems during exercise

• Causes

  • ↑ HR, BP, CO, breathing rate/depth, ventilatory drive

  • Redistribution of blood toward working muscle

muscle spindle

this mechanoreceptor detects changes in length and rate of shortening and are located parallel to the muscle fiber

muscle contraction

the response of muscle spindles is

GTOs

_____ is located in the tendon in series with muscle fibers and they detect muscle force and tension

reflex relaxation

the response of a GTO is

intrafusal

this type of fiber is located inside the muscle spindle and it helps the spindle detect changes in muscle length

extrafusal

this type of fiber is normal skeletal muscle fibers and is responsible for producing force

gamma motor neuron

this structure helps intrafusal fibers contract along with the muscle so the spindle does not become slack during contraction

cell body

this part of the neuron contains the nucleus

dendrites

this part of the neuron conducts impulses toward the cell body

axon

this part of the neuron carries electrical impulses away from the cell body

schwann cells

this part of the neuron forms myelin sheath around the axon to speed up conduction

synapse

this part of the neuron is the contact point/gap between the neurons

irritability and conductivity

what are the two characteristics of a neuron that allow it to transmit nerve impulses

false

true or false: when a neuron is at rest the inside is positive and the outside is negative

-70mv

what is the value for the RMP

fixed anions, leaky K+ and Na/K pump

why is the RMP negative

depolarization

during ____________ voltage gated Na+ channels open and the cell becomes more positive due to Na+ rushing into the cell

repolarization

during ________ Na+ channels close, voltage-gated K+ channels open, K+ moves out of the cell, and the inside becomes negative

hyperpolarization

during _________ K+ channels close too slowly, so too much K+ leaves, causing the RMP to become too negative

sodium potassium pump

what structure restores the normal ion gradient after an action potential

absolute refractory period

a time when a new action potential is impossible, no matter how strong the stimulus is due to Na+ channels being inactivated

relative refractory period

a time when a new action potential can occur, but only if the triggering stimulus is stronger than usual because the membrane is hyperpolarized

presynaptic

does the pre or postsynaptic neuron release a neurotransmitter?

postsynaptic neuron

does the pre or postsynaptic neuron receive the neurotransmitter?

EPSP

depolarizes the postsynaptic membrane and makes it more likely to reach threshold

IPSP

hyperpolarizes the membrane and makes it less likely to reach threshold

temporal summation

occurs when a single presynaptic neuron fires multiple signals in rapid succession at the same synapse

spatial summation

occurs when multiple presynaptic neurons fire at the same time

alpha motor neuron

large lower motor neurons in the spinal cord and brainstem that directly trigger the contraction of skeletal muscles

spinal cord

where is the cell body of an alpha motor neuron located

collateral branches

what are the branches of the alpha motor neuron called that innervates a muscle fiber

motor unit

made up of 1 motor neuron + all the muscle fibers it innervates

precise

if there is a low innervation ratio (23 fibers : 1 neuron) is there precise or lose control

powerful

if there is a high innervation ratio (1600 fibers : 1 neuron) is this for small or powerful movements

fascicle

a bundle of muscle fibers

muscle fiber

the individual muscle cell

myofibril

 bundle of contractile proteins inside a muscle fiber

sarcomere

functional unit of muscle contraction

myofilaments

the contractile proteins (ex: actin and myosin)

actin

is the thin filament actin or myosin?

myosin

is the thick filament actin or myosin?

epimysium

this layer of tissue surrounds the entire muscle

perimysium

this layer of tissue surrounds a fascicle

endomysium

this layer of tissue surrounds an individual muscle fiber

cylindrical

what shape is a muscle fiber that helps the muscle to lengthen and shorten during contraction

myonuclei

this structure houses the DNA for making proteins for muscle growth and repair

satellite cell

stem cells found in skeletal muscle that repair and regenerate damaged muscle fibers

myonuclear domain

theory that states that each myonucleus can only support a limited amount of cytoplasm so when muscle fiber grows so more myonuclei are needed

sarcoplasmic reticulum

specialized network of membrane-bound tubules inside muscle cells that stores and releases the calcium ions needed for muscle contraction and relaxation

t tubules

intermingled network that weaves through the fiber and surrounds each myofibril and stores Ca2+ and releases it to trigger muscle contraction

z line

from what line to what line does the sarcomere run from

terminal cisternae

enlarged end sacs of the sarcoplasmic reticulum in muscle cells that store and release calcium ions to trigger muscle contraction

a band

the central, dark-appearing band that spans the entire length of the thick myosin filaments, including areas where thin and thick filaments overlap

false

true or false: the a band changes length during contraction

I band

the light-appearing band located at the edges of the sarcomere that contains only thin actin filaments and gets shorter during contraction

Z line

the dark, zigzagging protein boundary line at each end of the sarcomere that anchors thin actin filaments and connects adjacent sarcomeres

true

true or false: the z line gets closer together during contraction

shortened

if the H zone gets smaller in the muscle lengthened or shortened?

shortened

if the I band gets smaller, is the muscle lengthened or shortened?

m line

a thin line running straight down the exact center of the H-zone and sarcomere, anchoring the thick myosin filaments

h zone

the lighter, central region within the A-band where there is no overlap with thin filaments, containing only thick myosin filaments

cross bridge cycling

is the sliding filament theory or the cross bridge cycling the MECHANISM of muscle contraction?

troponin

Ca+ binds to _____ which changes shape and causes tropomyosin to move exposing the actin binding sites.

ATP

when ____ binds to the myosin head, the myosin detaches from actin

myosin ATPase

what enzyme hydrolyzes ATP during cross bridge cycling

Pi

when ____ is released, a signal is sent and the power stroke begins

midline

during cross bridge cycling myosin head pulls actin toward the _______ of the sarcomere

ADP

when _____ is released the power stroke completes

SR/sarcoplasmic reticulum

when the stimulus is removed after muscle contraction the Ca+ is pumped back into the _____-

neuromuscular junction

the specialized chemical synapse where a motor neuron meets a skeletal muscle fiber to trigger muscle contraction

motor end plate

the folded region of the sarcolemma at the neuromuscular junction

neuromuscular cleft

the tiny gap between a motor neuron and a skeletal muscle fiber

voltage gated calcium

during excitation contraction coupling, an AP arrives at the axon terminal and this triggers the _________ channels to open

ACh

_____ binds the receptor on the motor end plate which causes Na+ to enter the muscle fiber