quiz questions for exam 1

In negative-feedback mechanisms, the ____ establishes the set point around which the variable is maintained

control center

The RQ of an animal is determined to be 0.72. This indicates that the diet of the animal is predominantly ____.

lipids

An important extracellular (e.g., found in blood plasma) buffer in animals is ____.

bicarbonate

One of the first to perform experiments to explain body function.

Galen

If you become too hot, ____ of blood vessels close to the skin are ____ feedback responses used to maintain your body temperature.

sweating & vasodilation ... negative

The pH of pure water ____

decreases as temperature increases

During heat stress, cells increase the levels of molecular chaperones called ____ that bind to denatured proteins and fold them into the proper configuration.

heat shock proteins

Organism that can only survive over a relatively narrow range of environmental salinity.

stenohaline

A cell in a(n) ____ environment will gain water and burst

hypotonic

The process of physiological ____ observed for closely-related animals adapted to very different environments illustrates the ____.

divergence ... evolutionary modification of originally similar physiological processes to cope with different problems

A pK value of 2 for a substance indicates a ____.

strong acid

An advantage of storing energy in lipid molecules (as opposed to energy storage in carbohydrate molecules) is that lipid ____.

has a higher energy content per gram

Human body temperture averages 37C but fluctuates from 37.5 to 36.5C. A temperature of 37C can therefore be considered the ____ for this variable.

set point

Stored as glycogen granules

carbohydrates

Integrative physiologists study the physiology of animals at the ____ level.

cellular, ecological and organismal

Most of the molecules in the cell membrane that serve as receptors, ion channels and carriers are _____.

proteins

Animals often alter the fluidity of cell membranes by altering the amount of ____.

cholesterol

Given these characteristics: substance moves down concentration gradient and does not require a carrier molecules. Which of these processes is described?

simple diffusion

Organism with internal osmotic concentration that is the same as the osmotic concentration of the environment.

osmoconformer

The physiological adjustment to several environmental factors for an animal in a natural environment (e.g., adjustment between seasons for a temperate animal).

acclimatization

____ is considered to be the "founder of ecological physiology" in the early 20th century.

Bartholomew

If the extracellular fluid has a lower total solute concentration than the intracellular fluid, then we say the extracellular fluid is ____.

hyposmotic

A solution of pH 10 has ____ hydrogen ions and is more ____than a solution with pH 8.

fewer … basic

A substance moves down its concentration gradient across a membrane and the trans-membrane movement requires carrier molecules. Which processes is described

facilitated diffusion

____ ion channels open in response to a change in membrane potential.

voltage- gated

Opening of ____ ion gates produces the repolarization phase of an action potential.

potassium

____ binds to nicotinic receptors to stimulate contraction of skeletal muscle. These receptors are examples of fast-acting ____ receptors.

ACh ... ionotropic

The CNS is composed of ____.

interneurons

To trigger an action potential in a neuron, _____ must be generated to reach the threshold value of about ____.

many EPSPs ... -55 mV

Relatively ____ diameter nerve fibers help produce quick escape reflex responses in a ____.

large ... squid

A nerve signal would proceed most commonly in which order?

dendrite > soma > axon > synapse

____ is an amino acid that often functions as an inhibitory neurotransmitter.

GABA

The Na+ and K+ channels that open during an action potential are examples of ____ ion channels.

voltage-gated

Na+/K+ pumps contribute to the resting membrane potential because they transport ____ out of the cell for every ____ that are transported into the cell.

3 Na+ ... 2 K+

Stronger stimuli increase the ____ of action potentials that are generated in a sensory neuron.

frequency

The ____ remove bacteria and debris from the CNS.

microglia

Opening of Cl- channels in a post-synaptic neuron producing hyperpolarization would occur during an ____ postsynaptic potential.

inhibitory

In what way does the interior surface of a cell membrane of a resting (nonconducting) neuron differ from the external surface? The interior is ___ charged and contains ___.

negatively ... less Na+

The binding of ____ receptors elicits most of the characteristic changes in heart rate, blood flow, and lung ventilation during the "fight-or-flight response."

E and NE to alpha and beta adrenergic

Endorphins are ____ neurotransmitters.

protein

____ synapses are less common in vertebrate animals

Dendrodentritic

For a multipolar neuron, the area where signal reception occurs is the ____.

dendrite

Conduction speed of action potentials is relatively ____ when the axon is myelinated. The conduction of action potentials in myelinated neurons is called ____.

faster ... saltatory

Numerous nerve impulses from a single presynaptic neuron arrive at a synapse at closely timed intervals and exert a cumulative effect on the membrane potential of the postsynaptic cell. This is a description of ____.

temporal summation

Extensions of ____ surround brain capillaries and help form the blood-brain barrier.

astrocytes

Motor neuron axons are also known as ____ nerve fibers.

efferent

Most neurons are ____ with one axon and many dendrites

multipolar

For most neurons, vesicles containing neurotransmitter are found in the ____ of a neuron.

axon terminal

During the course of an action potential, a very strong (suprathreshold) stimulus can generate a second action potential during the _____ refractory period when ____ gates are open.

relative ... K+

During the depolarization phase of an action potential in a neuron, ____ gates open and these ions move ____ the cell.

Na+ ... into