Exam 50: Sensory and Motor Mechanisms

"Marine cone snails from the genus Conus are estimated to consist of up to 700 species. These predatory molluscs have devised an efficient venom apparatus that allows them to successfully capture polychaete worms, other molluscs, or in some cases fish as their primary food sources. ) . . conotoxins from Australian species of Conus . . . have the capacity to inhibit specifically the nicotinic acetylcholine receptors in higher animals." (B. G. Livett, K. R. Gayler, and Z. Khalil. 2004. Drugs from the sea: Conopeptides as potential therapeutics. Current Medicinal Chemistry 11:1715-23.) -This particular conotoxin inhibits acetylcholine receptors that are located ________.

When the mammalian brain compares the actual temperature of the body to the preferred temperature of the body, which general component is being used?

An endoskeleton is the primary body support for the ________.

A physiologist is studying the homeostatic control of blood pH. What type of receptor might be responsible for detecting changes in blood pH?

Which of the following are present in high densities in both smooth and skeletal muscle cells? I. cilia II. mitochondria III. nuclei IV. intercalated disks

A ball-and-socket joint connects ________.

The muscles of a recently deceased human can remain in a contracted state, termed rigor mortis, for several hours, due to the lack of ________.

The blind spot in the human retina is the location that has the collected axons of ________.

The contraction of skeletal muscles is based on ________.

Although some sharks close their eyes just before they bite, their bites are on target. Researchers have noted that sharks often misdirect their bites at metal objects and that they can find batteries buried under sand. This evidence suggests that sharks keep track of their prey during the split second before they bite in the same way that

Lateral inhibition via horizontal cells in the mammalian retina ________.

The round window ________. I. dampens fluid vibrations II. collects sound pressure waves III. detects the frequency of sounds

A person able to hear only low-frequency sounds would probably have which of the following structural problems in the ear?

Partial or complete loss of hearing (deafness) can be caused by damage to the ________. I. axons of the neurons associated with each hair cell that carry information to the brain II. hair cells (the sensory receptors) in the cochlea III. tympanic membrane, or eardrum

The umami receptor in the sense of taste detects ________.

During the contraction of a vertebrate skeletal muscle fibre, calcium ions

Two students studying physiology taste a known "bitter" substance, and both report sensing bitterness. They then sample another substance. Student A reports sensing both a bitter taste and a salty taste, but student B reports only a salty taste. What is the most logical explanation?

The middle ear converts

It can be very difficult to select an angle for sneaking up to a grasshopper to catch it because grasshoppers have ________.

"Chitin" is a major component of the ________.