544 Answers to Illustration QuestionsBasophils and mast cells are part of subcuta-
neous tissue and produce histamine and
leukotrienes that contribute to inflammation.
14–7: Memory B cells and T cells provide memory;
each cell remembers one specific foreign anti-
gen.
14–8: The attached antibodies change the shape of
the toxin, and it cannot fit where it might pro-
duce harmful effects. (A step further: What
happens to a virus?)
14–9: After a second exposure, IgG production is
faster and in greater quantity. (A step further:
Explain how a vaccine could be part of this
illustration.)CHAPTER 1515–1: The conchae resemble curled shelves or scrolls;
they increase the surface area of the nasal
mucosa. (Let’s go a step further: What are the
functions of the nasal mucosa?)
15–2: The epiglottis covers the larynx during swal-
lowing, like a lid or trap door.
15–3: Exhaled air makes the vocal cords vibrate.
15–4: The right and left primary bronchi have C-
shaped cartilages to keep them open and are
lined with ciliated epithelium.
15–5: The cell of the alveolus and the cell of the cap-
illary are part of the respiratory membrane.
Alveolar type II cells secrete pulmonary surfac-
tant. Alveolar macrophages phagocytize
pathogens and dust.
15–6: During a normal exhalation, the diaphragm and
external intercostal muscles are relaxing (not
contracting as they do for inhalation). (A step
further: Which muscles are involved in a forced
exhalation?)
15–7: Tidal volume inspiratory reserve expira-
tory reserve vital capacity. Residual volume
cannot be measured with a spirometer. (A
step further: Why is residual volume impor-
tant?)
15–8: In external respiration, oxygen moves from the
air in the alveoli to the blood in the pulmonary
capillaries. In internal respiration, CO 2 moves
from the tissues (cells) to the blood in the sys-
temic capillaries.
15–9: The inspiratory center in the medulla directly
stimulates inhalation: The red arrows go
directly from the center to the respiratory mus-cles. (A step further: What other part of the
brain contains respiratory centers?)
15–10: Increased rate and depth of breathing will cor-
rect both imbalances, by taking in more O 2 or
exhaling more CO 2.CHAPTER 1616–1: Digestion takes place in the oral cavity, stom-
ach, and small intestine.
16–2: The pulp cavity (with blood vessels and
nerves) and the dentin (similar to bone) are
living. Another way of knowing that parts of a
tooth are living is that a cavity that has eroded
through the enamel causes pain.
16–3: The salivary glands are exocrine glands
because they have ducts. Saliva is made from
blood plasma. (Let’s go a step further: What is
saliva made of?)
Table Start at the protein box and follow the
Fig. arrows backward to the stomach, pancreas,
16–A: and small intestine. (A step further: Be sure
you can do the same for carbohydrates and
fats.)
16–4: The external muscle layer contracts locally for
mechanical digestion and in waves for peri-
stalsis.
16–5: The pyloric sphincter prevents backup of food
from the duodenum to the stomach.
16–6: Blood flows from the hepatic artery and portal
vein through the sinusoids to the central vein
of the lobule and to the hepatic vein. (A step
further: What is found in the blood from the
portal vein?)
16–7: The acini secrete the pancreatic enzymes and
bicarbonates.
16–8: The villi increase the surface area for the
absorption of end products of digestion, as do
the microvilli and plica circulares.
16–9: The ileocecal valve prevents backflow of fecal
material from the cecum to the ileum.
16–10: The internal anal sphincter is a continuation
of the circular muscle layer of the rectum.CHAPTER 1717–1: The cooling responses occur because the body
temperature is higher than that of the hypo-
thalamic thermostat; the fever has broken.29Scanlon(p3) App-G 8/17/06 11:08 AM Page 544