BIO C21 & C22

Blood flows rapidly within the arterial system but slows dramatically as it enters the capillaries. What is the benefit of having blood move slowly through the capillaries?

It ensures that the blood has enough time to exchange material with the surrounding cells.

If you were to step on a nail with your right foot, which of the following things would NOT happen?

Motor output from your right leg would be interpreted by your brain as sensory input.

The structures that carry signals away from the cell body of a neuron are called

axons.

________ is the process of expelling carbon dioxide from the lungs and taking oxygen into the lungs.

breathing

When eating dessert, you notice the sweetness of sugar when ________ are stimulated.

chemoreceptors

The external signals and information that are received by an organism are called

stimuli.

Which of the following does NOT facilitate exchange of materials by diffusion?

the presence of the extracellular matrix within connective tissue

A newborn is diagnosed shortly after birth with a rare heart defect that prevented the valve between the left atrium and the left ventricle from fully forming. Which of the following would be an expected outcome of this defect?

Body cells would receive less oxygen-rich blood than normal

Why do humans rely on a circulatory system to distribute oxygen?

Diffusion is very slow over all but the shortest distances, so oxygen must be delivered to our cells to speed up the process.

Which of the following statements about hemoglobin is true?

Hemoglobin binds to oxygen and releases it near cells that are performing cellular respiration

Which of the following statements best explains how one hormone can regulate several different developmental events?

One hormone can affect different types of target tissues in different ways

Which of the following things happens during inhalation?

Oxygen-rich air enters the alveoli

Which of the following statements about the peripheral nervous system (PNS) is NOT true?

The PNS may integrate and process information.

The steroid hormones testosterone, estradiol, and progesterone enter target cells and bind intracellular receptors to regulate gene expression. Based on this information, which of the following statements about steroid hormones must be correct?

They are mainly nonpolar and hydrophobic

In cystic fibrosis, parts of the respiratory tract can become clogged with mucus, inhibiting gas exchange. The area(s) of the respiratory tract where gases are directly exchanged is/are the

alveoli.

The force of blood pushing against the walls of blood vessels is called ________.

blood pressure

The blood vessels that allow diffusion between blood and nearby body cells are

capillaries.

The ________ of a neuron contain(s) all of the structures, such as a nucleus, that are common to animal cells.

cell body

The thalamus is part of the ________ nervous system

central

Antidiuretic hormone (ADH) is produced by the pituitary gland when the brain detects lower-than-optimum levels of water in the body. In the kidneys, ADH promotes the uptake of water, creating more concentrated urine. ADH travels from the pituitary gland to the kidneys through the

circulatory system

For a human to inhale, the rib muscles and the diaphragm must

contract, decreasing pressure inside the lungs

Which of the following sequences correctly describes the pathway that a signal travels in a neuron?

dendrite to cell body to axon

Which of the following processes is NOT a function of nephrons?

diffusion of oxygen into body cells

If the glomerulus remained intact but other capillaries were not in close physical contact with nephrons, which of the following functions would NOT be lost?

filtration of plasma

The liquid portion of human blood cannot absorb enough oxygen to meet the body's demands. However, ________ in our red blood cells greatly increase(s) the oxygen-carrying capacity of human blood.

hemoglobin

Once a hormone enters the bloodstream, it

is broken down after it has performed its function on the target cells.

As you are driving to school one morning, the driver in front of you suddenly slams on his brakes and turns right without using his turning signal. Despite the potentially irritating situation, you remain calm because your ________ helped you control your emotions.

limbic system

Blood leaving the right ventricle of the heart travels next to the

lungs.

Which of the following sensory receptor types is NOT found in humans?

magnetoreceptors

The sensory receptor types that provide information about body position and balance to help you coordinate your dance moves are

mechanoreceptors.

Serotonin, one of the hormones thought to be involved in depression, is a water-soluble molecule. Where on the target cell would you expect to find receptors for this hormone?

on the outside of the plasma membrane

Which of the following sequences correctly describes the journey of a molecule of oxygen from the pharynx to an alveolus?

pharynx to trachea to bronchus to bronchiole to alveolus

Receptors in the eye that provide vision are called ________.

photoreceptors

The majority of carbon dioxide is carried in the blood component called ________.

plasma

Another name for the "pacemaker" of the heart is the

sinoatrial (SA) node.

Which of the following organs coordinate(s) communication between the endocrine system and the nervous system?

the hypothalamus

Which component of whole blood would an investigator examine to determine the concentration of dissolved carbon dioxide or hormones, such as testosterone?

the plasma

Sensory neurons that contain specialized membrane channels activated by moderate temperatures are

thermoreceptors.

Which of the following functions occurs in the urinary bladder but NOT in nephrons?

urine storage

Large blood vessels that return deoxygenated blood from the legs to the heart are

veins.

Which of the following is a characteristic of an organ used for gas exchange?

very thin tissues

Air that is entering the lungs has

a higher concentration of oxygen and a lower concentration of carbon dioxide than air in an alveolus.

Which of the following features could be found in a vein, but NOT in an artery?

a one-way valve

Blood vessels that are designed to carry blood under high pressure are called ________. Blood vessels that have thin, porous walls are called ________.

arteries; capillaries

When blood arrives at an alveolus

the concentration of carbon dioxide is higher in the blood than in the alveolus.

If you were to compare the filtrate that is leaving the glomerulus to urine that is exiting the body, you would find that some substances — such as hydrogen ions and toxins — are more concentrated in the urine. Which of the following statements explains this process?

Hydrogen ions and toxins are secreted from capillaries.

One side of the heart pumps blood into the pulmonary circuit, and the other side of the heart pumps blood to the systemic circuit. How do these different functions affect the structure of the heart?

The left side of the heart has a thicker muscular wall than the right side.

Which of the following statements about hormones is true?

They may regulate certain developmental periods of life.

Which of the following statements accurately describes the movement of water and waste within a nephron?

Water and waste both filter through the glomerulus; water is later reabsorbed from capillaries.

Shortages of iron in our diet can cause iron deficiency anemia, a condition that reduces the amount of hemoglobin in red blood cells. Iron deficiency anemia is a potentially serious condition that is characterized primarily by

a reduction in the blood's capacity to transport oxygen.

The pulmonary ________ carries ________ blood from the heart to the lungs.

artery; oxygen-poor

The branched structures on a nerve cell that receive information are called

dendrites.

Gases move from an area of ________ concentration to an area of ________ concentration.

higher, lower

People with sickle-cell disease have deformed hemoglobin molecules and often suffer muscle pains, even at low levels of exertion. These symptoms might occur because the deformed hemoglobin

is unable to carry the amount of oxygen required for normal muscle activities.

A single hormone molecule can have dramatic effects on a target cell, because

it initiates a chain of events that amplifies its effect.

When the ________ of the heart contracts, blood is pumped into the systemic circuit.

left ventricle

The concentration of oxygen in blood plasma near an alveolus is lowered when

oxygen diffuses into red blood cells and binds to hemoglobin.

Valuable solutes, such as sugar and small proteins, that enter a nephron are ________ by capillaries.

reabsorbed

You accidentally rest your hand on a hot stove. This sensory information will ultimately be relayed to the appropriate part of your brain by the

thalamus.

At high altitudes, gases are less concentrated. You might gasp for air, because

the amount of oxygen that could diffuse into your blood will be decreased.

Which of the following structures has the smallest diameter?

the bronchioles

As you take this exam, which part of your brain is helping you decide which answer is correct?

the cerebral cortex

By what mechanism do most hormones travel through the organism that produces them?

the circulatory system

The breaking open of alveoli in people who have emphysema decreases their rate of gas exchange because

their lungs have less surface area available for diffusion.