peripheral nervous system - efferent division

central nervous system

• Subconsciously regulate homeostatic responses 

• Experience emotions 

• Voluntarily control movements 

• Be aware of body surroundings 

• Engage in other higher cognitive processes

Peripheral nervous system

• PNS: 

  • Cranial nerves (arise from brain) 

  • Spinal nerves (arise from the spine) 

  • Sensory nerves (afferent division) 

  • Motor nerves (efferent division)

    • Somatic (voluntary motor control): fibers of the motor neurons that supply the skeletal muscles 

    • Autonomic (involuntary control of muscles/organs): fibers that innervate smooth muscles, cardiac muscle, and glands 

main function of the ANS

• Efferent (motor) division of the PNS

  • Communication link by which the CNS controls muscles and glands, the effector organs that carry out intended actions

• Autonomic nervous system

  • Involuntary branch of the peripheral efferent division

• Somatic nervous system

  • Branch of the efferent division subject to voluntary control

different between autonomic and somatic nervous system

autonomic: involuntary

somatic nervous system: voluntary

What does it mean to have dual innervation?

Innervation of a single organ by both branches of the autonomic nervous system

what divison is fight or flight

sympathetic

what division is rest and digest

parasympathetic

how beneficial is it to have a dual autonomic innervation

so neither the sympathetic or parasympathetic is dominating one another

what is unique about the adrenal medulla

modified part of the sympathetic nervous system, adrenal glands are endocrine glands, adrenal medulla secretes catecholamine hormones on stimulation

what is diverse about the somatic nervous system

branch of the efferent division subject to voluntary control

characteristics associated with the neuromuscular junction

motor neurons and skeletal muscle fibers: chemically linked at neuromuscular junctions, each muscle cell has one neuromuscular junction

muscle fiber: single, long, and cylindrical muscle cell

motor end plate: shallow depression where axon terminals end

what neurotransmitter for neuromuscular junction

ACh → initiation of an action potential

what ends ACH activity and what does this enzyme break down

enzyme in the motor end-plate membrane that turns off muscle cells electrical response

what is the function of controlled muscle contractions

produce movement, maintain posture, stabilize joints, and generate heat

how are muscles categorized

according to structure and control

where are categorized muscles located

striated: skeletal and cardiac muscle

unstriated: smooth muscle

voluntary: skeletal muscle (somatic)

involuntary: cardiac and smooth muscle (autonomic)

what is unique about skeletal muscle fibers

theyre voluntary

A bands

thick and thin filaments overlap

I band

only thin filaments, no overlapping

cross-bridges

bridge like structure that form when the heads of myosin filaments attach to actin filaments in muscle cells

myosin

thick

thin

actin

sliding filament theory

thin filaments from the opposite sides of each sarcomere slide closer together between the thick filaments

power stroke

motion pulls the thin filament toward the center of the sarcomere, uses ATP

why is calcium so important in excitation and concentration

spread of action potential down transverse tubules, calcium release form sarcoplasmic reticulum, ATP-powered cross-bridge cycling

what form of tissue will be used to attach muscles to bones

tendons

what type of force is produced when a muscle pulls on a bone

tension force

what factor can manipulate a graded contraction

number of muscle fibers contracting (depends on the extent of motor unit recruitment)

contractions can be varying

strength

which pathway produces the most ATP? least amount of ATP

oxidative phosphorylation

fast skeletal fibers

fine motor, quick burst of movement, depend more on glycolysis, don’t need as much myoglobin, have less density, lower capillaries, extraocular muscle in the eye and your tongue

slow skeletal fibers

really slow contraction; don’t fatigue as easily; depend on oxidative phosphorylation to produce ATP; higher concentration of capillaries which move oxygen and makes it red; higher concentration of myoglobin (binds oxygen to muscle tissue); ex; muscles that are tonically contracted (contracted all the time)

oxidative phyosphylation

muscles utilized during aerobic exercise or endurance training; makes 28 ATP (whole process makes 32 ATP) 

glycolic

slow process; high intensity exercise or anaerobic exercise; makes 2 ATP; causes muscle soreness 

how will genetics impact muscle fiber types

your genes largely determine the proportion of slow-twitch (type I) and fast-twitch (type II) muscle fibers you have, impacting your potential for endurance activities or explosive power based on your natural muscle fiber composition

when muscles adapt what are some noticeable differences

Muscle hypertrophy: increase in size of muscle cell

how are motor activities classified

gross or fine motor

what will happen to smooth muscles when relaxed

widening or dilation of the structure they surround