Chapter 50 - Sensory and Motor Mechanisms

Skeletons

________ can be hydrostatic and supported by fluid pressure, as in worms; hardened into exoskeletons, as in insects; or endoskeletons, as invertebrates.

Sensory information

________ can be processed before, during, and after- action potential transmission to the CNS.

Sarcomeres

________ are repeating units made up of these filaments.

Mechanoreceptors

________ detect flowing fluid or settling particles in hearing and balance.

cones

Both rods and ________ have a pigment called retinal that is linked to a protein (opsin)

CNS

The resultant receptor potential regulates action potential transmission to the ________, where sensory input is processed to create perceptions.

Acetylcholine

________ is released by motor neurons, which causes action potentials in muscle fibers, which promote the release of Ca2+ from the sarcoplasmic reticulum.

Myofibrils

________ are made of thin filaments of (mainly) actin and thick filaments of myosin in the muscle cells (fibers) of vertebrate skeletal muscle.

single lens

A(n) ________ in the vertebrate eye focuses light on photoreceptors in the retina.

Synapses

________ carry information from photoreceptors to cells that integrate information and send it to the brain through the optic nerve's axons.

Light absorption

________ by the retina initiates a signal transduction pathway that hyperpolarizes the photoreceptors, leading them to release fewer neurotransmitters.

Nervous system input

________ regulates the pace at which the heart contracts, but it is not necessarily necessary.

Ca2+

When ________ binds to the troponin complex, tropomyosin shifts, exposing the myosin- binding sites on actin and triggering cross- bridge formation.

motor unit

A(n) ________ is made up of a motor neuron and the muscle fibers it regulates.

Sensory cells

________ in taste buds in humans express a receptor type that is unique to one of the five flavor perceptions: sweet, sour, salty, bitter, and umami (elicited by glutamate)

basilar membrane

The fluid's pressure waves shake the ________, depolarizing hair cells and generating action potentials that go to the brain through the auditory nerve.

shift

The ________ in ion flow across the membrane that results affects the membrane potential.

sensory integration

In many situations, ________ occurs as soon as the information is received.

Cardiac muscle

________ is present in the heart and is made up of striated cells that are electrically linked by intercalated disks.

Sensory receptor action potentials

________ pass along neurons that are dedicated to a certain stimulus; these dedicated neurons make synapses with specific neurons in the brain or spinal cord.

sensory receptors

Some ________ respond to internal cues such as blood pressure and body posture.

Taste

________ and smell both rely on comparable sets of sensory receptors.

characteristics of an action potential

The ________ caused by light striking the eye are the same as those of an action potential triggered by air vibrating in the ear.

Slow twitch

________ or fast- twitch skeletal muscle fibers can be oxidative or glycolytic.

Muscle function

________ is dependent on the physical interaction of protein filaments.

Sensory receptors

________ convert stimulus energy and send it to the central nervous system.