Exam 4 Intro Physiology

Which of the following actions is not a function of the epithelium? Regulates the excretion of waste. Allows the internal environment to alter its conditions to match those of the external environment. Creates an internal environment that is different from the external environment. Controls the exchange of nutrients between the internal and external environments.

Allows the internal environment to alter its conditions to match those of the external environment.

Which of the following statements describes a negative feedback response? A person who loses 3 pounds continues to diet to lose an additional 10 pounds. The onset of contractions during childbirth stimulates the release of a hormone that stimulates further contractions. After a meal, blood sugar levels in the body rise; insulin is secreted to lower blood sugar levels. The arrival of platelets at a wound site stimulates the recruitment of more platelets to form a clot.

After a meal, blood sugar levels in the body rise; insulin is secreted to lower blood sugar levels.

You inject an animal with a drug that loosens the tight junctions between epithelial cells. What do you predict will immediately occur? Excess water will enter into the organism. Nothing will happen. Nerves will no longer conduct electrical signals. Muscles will no longer contract.

Excess water will enter into the organism.

Which component of a homeostatic system sends instructions based on sensory information? Integrator. Sensor. Effector. Set point.

Integrator

Which term describes a mechanism by which the internal conditions of an organism are kept at set values without regard to the external conditions? Negative feedback. Conformational homeostasis. Regulatory homeostasis. Thermoregulation.

Regulatory homeostasis.

Some animals have no gills when young, but then develop gills that grow larger as the animal grows larger. What is the reason for this increase in gill size? Relative to their surface area, the young have more volume in which they can store oxygen for long periods of time. The young of these animals are much more active than the adult, which leads to a higher BMR and therefore a higher need for oxygen. The young have a higher basal metabolic rate. Relative to their volume, the young have more surface area across which they can transport all the oxygen they need.

Relative to their volume, the young have more surface area across which they can transport all the oxygen they need.

Which component of a homeostatic system perceives changes in some parameter of the environment? Effector. Sensor. Integrator. Set point.

Sensor.

Which of the following actions acts to warm a homeothermic body? Shivering. Dilating blood vessels. Sweating. Panting.

Shivering

Which of the following is a true statement about body size and physiology? The rate at which an animal uses nutrients and produces waste products is independent of its volume. The amount of food and oxygen an animal requires and the amount of heat and waste it produces are inversely proportional to its mass. Small and large animals face different physiological challenges because an animal's body mass increases cubically while its surface area increases as a squared function. The wastes produced by an animal double as its volume doubles, and triple as its surface area triples.

Small and large animals face different physiological challenges because an animal's body mass increases cubically while its surface area increases as a squared function.

Which of the following has the highest surface area/volume ratio? elephant human bacterium mouse

bacterium

An elephant and a mouse are running in full sunlight, and both overheat by the same amount above their normal body temperatures. When they move into the shade and rest, which animal will cool down faster? They will cool at the same rate because they overheated by the same amount. The elephant will because it has the lower surface area/volume ratio. The elephant will because it has the higher surface area/volume ratio. The mouse will because it has the higher surface area/volume ratio.

The mouse will because it has the higher surface area/volume ratio.

If an organism was discovered that had no epithelial tissues, it would require adaptations to maintain homeostasis in which of the following areas? The organism would required adaptations in its muscular system for movement. The organism would require adaptation in its circulatory system for transport of blood. The organism would require adaptations that would prevent water loss from the body in a terrestrial environment. The organism would require adaptations in its nervous system for sensing external stimuli. The organism would require adaptations in its skeleton for structure.

The organism would require adaptations that would prevent water loss from the body in a terrestrial environment.

What is the main reason that a person sitting on the beach with an air temperature of 15°C loses heat less rapidly than when immersed in lake water at 15°C? Water conducts heat more efficiently than air does. Water evaporates, and heat is lost to evaporation. Metabolic heat production is greater in air than in water. Air is a poor insulator.

Water conducts heat more efficiently than air does.

Which of the following is an example of negative feedback? During contractions, oxytocin (a hormone) is released and acts to stimulate further contractions. After a blood vessel is damaged, signals are released by the damaged tissues that activate platelets in the blood. These activated platelets release chemicals that activate more platelets. When a baby is nursing, suckling leads to the production of more milk and a following increase in the secretion of prolactin (a hormone that stimulates lactation). When the level of glucose in the blood increases, the pancreas produces and releases the hormone insulin. Insulin acts to decrease blood glucose. As blood glucose decreases, the rate of production and release of insulin decreases as blood glucose decreases.

When the level of glucose in the blood increases, the pancreas produces and releases the hormone insulin. Insulin acts to decrease blood glucose. As blood glucose decreases, the rate of production and release of insulin decreases as blood glucose decreases.

Which do you predict would have the largest difference in mass-specific basal metabolic rate? lion and cat dog and cat lion and dog cat and mouse

cat and mouse

Which one of the following is not a good strategy for increasing the surface area of an object relative to the volume? enlarge and make more spherical increase the amount of folding make flatter increase the amount of branching None of these are good strategies.

enlarge and make more spherical

Which term best describes an animal that, although generating a significant amount of heat through metabolism, nonetheless does not maintain a constant body temperature? heterothermic ectotherm homeothermic ectotherm homeothermic endotherm heterothermic endotherm

heterothermic endotherm

When comparing a mouse to an elephant, the mouse has a _____ surface area to volume ratio and a _____ mass-specific basal metabolic rate. lower; lower higher; higher lower; higher higher; lower

higher; higher

When the mammalian brain compares the actual temperature of the body to the preferred temperature of the body, which general component is being used? integrator sensor stimulating sweat glands to increase evaporation effector both constriction of skin blood vessels to decrease heat loss and stimulation of sweat glands to increase evaporation

integrator

The best definition of an endotherm is an animal that _____. allows its body temperature to rise or fall depending on environmental conditions relies primarily on heat gained from the environment keeps its body temperature constant produces adequate heat to warm its own tissues

produces adequate heat to warm its own tissues

A woman standing and watching the stars on a cool, calm night will lose most of her body heat by which mechanism? radiation convection conduction evaporation radiation and convection only

radiation

An animal warming up in the sun is gaining heat via _____. conduction evaporation convection radiation

radiation