Exam 4

A stimulus is information from the environment that is converted to a sensory signal in the body. 

A sensory receptor is a cell that is capable of detecting stimuli and communicating this information to the central nervous system. 

Sensory transduction is the conversion of an environmental stimulus (such as light energy) to an electrical communication system within the body. 

A signal transduction pathway is a series of proteins within a cell that passes a signal along from one molecule to another until a final reaction occurs. 

Sensory adaptation is the tendency for repeated stimuli to become less noticed over time. 

Which part of the eye gives the eye its color? Iris 

When light levels suddenly increase, our eyes adjust quickly by reducing the size of the __________. Pupil 

The receptor potential is the __________. Membrane potential produced in the receptor cell by sensory transduction 

__________ is an example of sensory adaptation. Ignoring the feeling of shoes on your feet 

In all types of chemoreceptors, receptor cells develop receptor potentials in response to __________. Chemicals dissolved in a fluid such as blood or saliva 

Standing out in center field, a baseball player watches a hitter's bat strike the ball and then, slightly later, hears the sound of the impact. What types of sensory receptors did the player just use? Photoreceptors and mechanoreceptors 

Thermoreceptors detect __________. Temperature 

A person who cannot focus well on distant objects has __________. Nearsightedness 

A person who has blurred vision caused by a misshapen lens or cornea has __________. Astigmatism 

A person whose eyeball is shorter than normal suffers from __________. Farsightedness 

*Sensory receptors are located in and sound is detected in the ________. Cochlea 

A thermoreceptor in the skin converts heat energy to nerve impulses. This conversion is called __________. Sensory transduction 

What is an example of sensory adaptation? After two hours of driving the neighborhood ice cream van, you no longer hear the chimes 

As light passes into the human eye, it goes through a/an/the __________ first. Cornea 

Blurred vision caused by a misshapen lens or cornea is called __________. Astigmatism 

The part of the human ear that contains sensory neurons for sound detection is called the __________. Cochlea 

Which sense is based on detection of electromagnetic activity? Vision/Sight 

All animals respond to stimuli, which are signals from the environment such as light and sound. This response, which can happen very quickly, requires several steps. First, cells called sensory receptors within sensory organs must detect a stimulus. To be communicated throughout the animal body, the sensory information must undergo a process called sensory transduction, which converts the sensory information into electrical impulses. The electrical impulses travel as action potentials along neurons. The data from the electrical signal is ultimately passed to the central nervous system, which processes the information and formulates a response, such as the movement of a muscle. 

*What is the correct order of the parts of the vertebrate when light strikes them as it enters the eye? Cornea, aqueous humor, lens, vitreous humor, retina 

* 

Bind: The myosin head binds to actin 

Power stroke: The myosin head pulls the actin filament, shortening the sarcomere 

Detach: ATP binds to the myosin head, causing it to release from actin 

Extend: The breakdown of ATP causes the myosin head to extend and prepare for another cycle 

When you bend your elbow, a muscle that is connected to the forearm bone by tendons pulls the forearm toward the shoulder. The upper arm bone is connected to the forearm bone by ligaments, forming a hinge joint, which moves only in one plane. Rotation at the elbow is enabled by a pivot joint between the upper and lower arm bones. The shoulder has a greater range of movement than the elbow because of the ball-and-socket joint where the upper arm joins the shoulder blade. 

Which part of the bone contains/stores fat? Yellow bone marrow 

The joint that allows you to rotate your forearm so that your hand changes from a palm up position to a palm down position must be a ________ joint. Pivot 

What best helps a broken bone heal? Returning the broken bone parts back to their natural shape and then immobilizing the bone 

Muscles are connected to bones by __________. Tendons 

Functionally, what is the muscle fiber’s fundamental unit of contraction? Sarcomere 

A thick filament is made up of  __________. Myosin 

According to the sliding-filament model of muscle contraction, a sarcomere contracts when its ________. Thin and thick filaments slide past each other 

What structure would probably have the largest motor units? A motor unit in the thigh to control leg movements 

A(n) __________ is the contractile unit of the skeletal muscle. Sarcomere