Chapters 13-20

What is the role of epimysium?

Surrounds the entire muscle.

What is a circular muscle?

Forms rings around body openings.

What do spinal nerves innervate?

Muscles below the neck.

What are somatic motor neurons?

Nerve cells serving skeletal muscles.

What are muscle cells known as?

Muscle fibers (myofibers).

When does VO2 max typically peak?

Around age 20.

What is a myogram?

A chart of muscle contraction timing.

What are dendrites?

Branches that receive signals from other neurons.

What do oligodendrocytes do?

Form myelin sheaths in CNS.

What is the threshold for action potential?

About -55 mV.

How many skeletal muscles does the human body have?

Over 600.

What connects muscle to bone?

Tendons.

What does muscle movement include?

Moving body parts and contents.

What is the specialized major function of muscle tissue?

Convert chemical energy in ATP into mechanical energy.

What is the significance of muscle architecture?

It relates to muscle strength and function.

What percentage of body weight do muscles constitute?

About half.

What are the three types of muscle tissue?

Skeletal muscle, Smooth muscle, Cardiac muscle.

What is the major function of muscle tissue?

Convert chemical energy in ATP into mechanical energy.

What is an example of a muscle name?

Depressor labii inferioris.

How are muscles typically named?

Using Latin names based on function or location.

What are the universal characteristics of muscle tissue?

Excitability (responsiveness), Conductivity, Contractility, Extensibility, Elasticity.

What does excitability in muscle tissue refer to?

Responsiveness to chemical signals and stimuli.

What is the study of the muscular system called?

Myology.

What are antigravity muscles responsible for?

Preventing us from falling over.

What is the role of sphincters in muscle function?

Control the movement of materials within the body.

What does perimysium wrap around?

Fascicles of muscle fibers.

What are the functions of muscles?

Movement, Stability, Control of openings, Heat production, Glycemic control.

How do muscles help with glycemic control?

By absorbing and storing glucose.

How do muscles contribute to stability?

By maintaining posture and preventing unwanted movements.

How much heat do muscles produce?

Up to 85% of the body's heat.

What does contractility mean in muscle tissue?

Muscle fibers shorten when stimulated.

What is conductivity in muscle tissue?

Local electrical excitation travels along the muscle fiber.

What is extensibility in muscle tissue?

Capability of being stretched between contractions.

What does elasticity refer to in muscle tissue?

Returns to original length after being stretched.

What are the connective tissues of muscles?

Endomysium: around each fiber, Perimysium: wraps fascicles, Epimysium: surrounds entire muscle, Fascia: separates muscle groups.

What is the function of endomysium?

It allows room for capillaries and nerve fibers.

Why is knowing innervation important?

It enables diagnosis of nerve injuries.

How do cranial nerves differ from spinal nerves?

Cranial nerves innervate head and neck muscles.

What happens to blood supply during heavy exercise?

Muscular system's share rises to over three-quarters.

What is the treatment for compartment syndrome?

Rest, immobilization, fasciotomy.

What does innervation of a muscle refer to?

Identity of the nerve that stimulates it.

What happens in compartment syndrome?

Pressure builds within a muscle compartment.

What is fascia in muscle structure?

Sheet of connective tissue separating muscles.

What is the role of a prime mover (agonist)?

Produces most of the force in an action.

What do spinal nerves do after emerging from the spinal cord?

Branch into posterior and anterior rami.

What is the role of epimysium?

Surrounds the entire muscle.

Which ion has the greatest influence on resting membrane potential?

Potassium.

What happens when a chemical stimulant binds to a receptor?

Opens sodium gates and allows sodium to enter.

What happens during depolarization of an action potential?

Sodium enters and depolarizes the cell.

What is the weight of the human brain in men?

1600 g or 3.5 lbs.

What do astrocytes do?

Support neurons and regulate blood flow.

What are the two major types of synapses?

Electrical and chemical synapses.

What neurotransmitter is released during presynaptic facilitation?

Serotonin.

What is the function of the cerebellum?

Coordination and balance.

What is the weight of the human brain in women?

1450 g or 3.2 lbs.

How do temporal and spatial summation differ?

Temporal is time-based; spatial is location-based.

What is the purpose of EPOC?

To replenish ATP and regenerate CP stores.

What happens to calcium concentration during relaxation?

Calcium concentration in cytosol falls.

What would happen with subthreshold stimuli?

No contraction occurs.

What is the significance of the stress-relaxation response in smooth muscle?

Allows hollow organs to fill gradually.

What is myopathy?

Any disease of muscle tissue.

What is an autonomic nervous system?

Regulates involuntary actions.

How do ependymal cells modify CSF?

They alter its ion composition.

What is the difference between smooth and skeletal muscle?

Smooth muscle is involuntary, lacks striations; skeletal muscle is voluntary and striated.

What is the effects of potassium accumulation in T tubules?

Causes fatigue in high-intensity exercise.

What does the term neural integration mean?

The ability to process and recall information.

What neurotransmitter is associated with presynaptic inhibition?

GABA.

What is hyperpolarization?

Membrane becomes more negative than resting potential.

What are sensory (afferent) neurons responsible for?

Detecting stimuli and transmitting information.

What role do satellite cells play?

Regeneration of damaged muscle tissue.

What connects the two lateral ventricles to the third ventricle?

Interventricular foramen.

What muscle type adapts for endurance?

Slow-twitch fibers.

What is flaccid paralysis?

State where muscles are limp and cannot contract.

What is the primary function of myelin?

Insulation around a nerve fiber.

What are common symptoms of meningitis?

High fever, stiff neck, drowsiness, headache.

What are the structures of the brainstem?

Medulla oblongata, Pons, and Midbrain.

What neurotransmitter is associated with excitatory postsynaptic potentials (EPSPs)?

Glutamate.

What happens when an action potential reaches the T-tubules?

It continues down into the cell interior.

What are the functions of the cerebellum?

Coordination of voluntary movements, balance, and motor learning.

What occurs during the contraction phase of a muscle twitch?

Muscle generates external tension.

What initiates muscle contraction?

Nerve signal arriving at the axon terminal.

What is the role of the basal lamina in the PNS?

It is external to the neurilemma.

What is the functional significance of the blood-brain barrier?

Protects brain from harmful substances.

What describes the organization of myofilaments in muscle cells?

Actin and myosin in a specific arrangement.

What happens during the repolarization phase of an action potential?

Potassium exits the cell.

What is the structure that allows the passage of cerebrospinal fluid?

Choroid plexus.

What determines the direction of messages from the brain to the body?

The side of the brain that processes the signals.

What is an example of a muscle name?

Depressor labii inferioris.

What is a key function of astrocytes?

Support neurons and regulate blood flow.

What does the motor action involve?

Contracting skeletal muscle to produce movement.

What is the function of the thalamus?

Directs incoming sensory messages to the cerebrum.

What is the role of intercalated discs in cardiac muscle?

Allow direct stimulation between cardiomyocytes.

How do the characteristics of fast and slow-twitch fibers differ?

Fast-twitch fibers are suited for speed; slow-twitch for endurance.

What is the role of neurotransmitters in the nervous system?

Transmit signals between neurons.

How is muscle tone maintained?

Nervous system keeps resting muscles near optimal length.

What event happens at the axon terminal during synaptic transmission?

Release of neurotransmitter to stimulate the next cell.

What neurons link motor and sensory pathways?

Interneurons.

What happens during excitatory postsynaptic potential (EPSP)?

Voltage change moves toward threshold.

What is lateral (external) rotation?

Bone spins to face laterally.

What is the effect of cholinesterase inhibitors?

Prevent degradation of acetylcholine, causing paralysis.