BISC 132 KeyTerms Exam4

Ectotherm: animal incapable of maintaining a relatively constant internal
body temperature

Endotherm: animal capable of maintaining a relatively constant internal body
temperature

Temporal fenestra: non-orbital opening in the skull that may allow muscles to expand and
lengthen

Channel protein: membrane protein that allows a substance to pass through its hollow core across the plasma membrane

Depolarization: change in the membrane potential to a less negative value

Hyperpolarization: change in the membrane potential to a more negative value

Neurotransmitter: chemical ligand that carries a signal from one nerve cell to the next

Chemoreceptors: receptors that are stimulated by chemicals or chemical changes

Mechanoreceptor: sensory receptor modified to respond to mechanical disturbance such as
being bent, touch, pressure, motion, and sound

Photoreceptors: receptors that are stimulated by electromagnetic radiation (such as light)

Sensory receptor: specialized neuron or other cells associated with a neuron that is modified to
receive specific sensory input

Thermoreceptors: receptors that are stimulated by changes in temperature

Endoskeleton: skeleton of living cells that produces a hard, mineralized tissue located within the soft tissue of organisms

Exoskeleton: a secreted cellular product external skeleton that consists of a hard encasement on the surface of an organism

Hydrostatic skeleton: skeleton that consists of aqueous fluid held under pressure in a closed
body compartment

Diaphragm: domed-shaped skeletal muscle located under lungs that separates the thoracic
cavity from the abdominal cavity