Chapter 1: Introduction to the Human Body

Question 1

The structural organization of the human body is _, _, _, _, _, and _.

Answer 1

Organismal, organ system, organ, tissue, cellular, chemical

Question 2

The integumentary system encloses _ _ _ and site of many _ _.

Answer 2

Internal body structures, sensory receptors

Question 3

The integumentary system includes _, _, and _.

Answer 3

Hair, skin, nails

Question 4

The skeletal system _ the body and _ _ (with muscular system).

Answer 4

Supports, enables movement

Question 5

The skeletal system includes _, _, and _.

Answer 5

Cartilage, bones, joints

Question 6

The muscular system _ _ (with skeletal system) and helps maintain _ _.

Answer 6

Enables movement, body temperature

Question 7

The muscular system includes _ and _.

Answer 7

Skeletal muscles, tendons

Question 8

The nervous system detects and processes _ _ and activates _ _.

Answer 8

Sensory information, bodily responses

Question 9

The nervous system includes _, _, and _.

Answer 9

Brain, spinal chord, peripheral nerves

Question 10

The endocrine system secretes _ and regulates _ _.

Answer 10

Hormones, bodily processes

Question 11

The endocrine system includes _, _, _, _, and _.

Answer 11

Pituitary gland, thyroid gland, pancreas, adrenal glands, testes/ovaries

Question 12

The cardiovascular system delivers _ and _ to _ and equalizes _ in the body.

Answer 12

Oxygen, nutrients, tissues, temperature

Question 13

The cardiovascular system includes _ and _.

Answer 13

Heart, blood vessels

Question 14

The lymphatic system returns fluid to _ and defends against _.

Answer 14

Blood, pathogens

Question 15

The lymphatic system includes _, _, _, and _.

Answer 15

Thymus, lymph nodes, spleen, and lymphatic vessels

Question 16

The respiratory system removes _ _ from the body and delivers _ to the blood.

Answer 16

Carbon dioxide, oxygen

Question 17

The respiratory system includes _, _, and _.

Answer 17

Nasal passage, trachea, and lungs

Question 18

The digestive system processes _ for use by the body and _ _ from undigested food.

Answer 18

Food, removes wastes

Question 19

The digestive system includes _, _, _, _, and _.

Answer 19

Stomach, liver, gall bladder, large intestine, and small intestine

Question 20

The urinary system controls _ balance in the body and removes _ from _ excretes them.

Answer 20

Water, wastes, blood

Question 21

The urinary system includes _ and _.

Answer 21

Kidneys and urinary bladder

Question 22

The male reproductive system produces _ _ and _ and delivers gametes to _.

Answer 22

Sex hormones, gametes, female

Question 23

The female reproductive system produces _ _ and _, supports _ until birth, and produces _ for infant.

Answer 23

Sex hormones, gametes, embryo/fetus, milk

Question 24

The male reproductive system includes _ and _.

Answer 24

Epididymis and testes

Question 25

The female reproductive system includes _ , _, and _.

Answer 25

Mammary glands, ovaries, and uterus

Question 26

The maintenance of essential body boundaries is _.

Answer 26

Organization

Question 27

Energy transfer via anabolic and catabolic reactions is _.

Answer 27

Metabolism

Question 28

The functional characteristics of human life are _, _, _, _, and _.

Answer 28

Organization, metabolism, responsiveness, movement, development

Question 29

Organization keep _ _ separated from _ _ threats and keep the cells _ and _.

Answer 29

Body cells, external environmental, moist, nourished

Question 30

Organization also separates _ _ _ from the countless microorganisms that grow on body surfaces, including the lining of certain tracts, or passageways.

Answer 30

Internal body fluids

Question 31

Although the body can respond to high temperatures by _ and to low temperatures by _ and _ _ _, long-term exposure to extreme heat and cold is not compatible with survival.

Answer 31

Sweating, shivering, increased fuel consumption

Question 32

The body requires a precise _ _ to maintain its gases in _ and to facilitate _—the intake of oxygen and the release of carbon dioxide.

Answer 32

Atmospheric pressure, solution, respiration

Question 33

Humans also require _ _ high enough to ensure that blood _ all body tissues but low enough to avoid damage to _ _.

Answer 33

Blood pressure, reaches, blood vessels

Question 34

The four requirements for human survival are _, _, _ _ _ _, and _ _ _ _ _.

Answer 34

Oxygen, nutrients, narrow range of temperature, and narrow range of atmospheric pressure

Question 35

Oxygen is a key component of the _ _ that keep the body alive, including the reactions that produce _.

Answer 35

Chemical reactions, ATP

Question 36

The three basic classes of nutrients are _, the -yielding and body- nutrients, and the _ (vitamins and minerals).

Answer 36

Water, energy, building, micronutrients

Question 37

The body’s functional chemicals are dissolved and transported in _, and the chemical reactions of life take place in _.

Answer 37

Water, water

Question 38

The breakdown products of carbohydrates and lipids can then be used in the _ processes that convert them to ATP.

Answer 38

Metabolic

Question 39

Micronutrients participate in many essential chemical reactions and processes, such _ _, and some, such as _, also contribute to the body’s structure.

Answer 39

Nerve impulses, calcium

Question 40

Pressure keeps gases within your body, such as the gaseous nitrogen in body fluids, _.

Answer 40

Dissolved

Question 41

Our ability to breathe—that is, to take in oxygen and release carbon dioxide—also depends upon a precise _ _.

Answer 41

Atmospheric pressure

Question 42

Homeostasis is the activity of _ throughout the body to maintain the _ state within a narrow range that is compatible with life.

Answer 42

Cells, physiological

Question 43

Homeostasis is regulated by _ _ loops and, much less frequently, by _ _ loops. Both have the same components of a _, _, _ _, and _.

Answer 43

Negative feedback, positive feedback, stimulus, sensor, control center, effector

Question 44

Negative feedback loops work to prevent an _ _ to the stimulus, whereas positive feedback loops _ the response until an end point is reached.

Answer 44

Excessive response, intensify

Question 45

A positive feedback loop results in a change in the body’s status, rather than a return to _.

Answer 45

Homeostasis

Question 46

A standard reference position for mapping the body’s structures is the normal _ _.

Answer 46

Anatomical position

Question 47

_ terms such as anterior and posterior are essential for accurately describing the relative locations of body structures.

Answer 47

Directional

Question 48

Images of the body’s interior commonly align along one of three planes: the _, _, or _.

Answer 48

Sagittal, frontal, transverse

Question 49

The body’s organs are organized in one of two main cavities— _ (also referred to posterior) and _ (also referred to anterior)—which are further sub-divided according to the structures present in each area.

Answer 49

Dorsal, ventral

Question 50

The serous membranes have two layers—_ and _—surrounding a fluid filled space.

Answer 50

Parietal, visceral

Question 51

Serous membranes cover the _ (pleural serosa), _ (pericardial serosa), and some _ organs (peritoneal serosa).

Answer 51

Lungs, heart, abdominopelvic

Question 52

The serous fluid produced by the serous membranes reduces _ between the walls of the cavities and the internal organs when they move, such as when the lungs inflate or the heart beats.

Answer 52

Friction

Question 53

Computed tomography (CT) is a noninvasive imaging technique that uses computers to analyze several _ _ in order to reveal minute details about structures in the body.

Answer 53

Cross-sectional X-rays

Question 54

CT is especially useful for _ _ scanning, such as of the brain and the thoracic and abdominal viscera. Its level of detail is so precise that it can allow physicians to measure the size of a mass down to a millimeter.

Answer 54

Soft tissue

Question 55

The main disadvantage of CT scanning is that it exposes patients to a dose of _ many times higher than that of X-rays.

Answer 55

Radiation

Question 56

Matter is exposed to _ _ and _ _ was found to emit radio signals. Magnetic Resonance Imaging has the major advantage of not exposing patients to _. It is especially used to identify _.

Answer 56

Magnetic fields, radio waves, radiation, tumors

Question 57

Drawbacks of MRI scans include their much _ _, and patient _ with the procedure. Patients with _-containing metallic _ (internal sutures, some prosthetic devices, and so on) cannot undergo MRI scanning because it can _ these implants.

Answer 57

Higher cost, discomfort, iron, implants, dislodge

Question 58

Functional MRIs (fMRIs), which detect the concentration of _ _ in certain parts of the body, are increasingly being used to study the activity in parts of the _ during various body activities.

Answer 58

Blood flow, brain

Question 59

Positron emission tomography is a technique involving the use of so-called _, substances that emit radiation that is short-lived and therefore relatively safe to administer to the body.

Answer 59

Radiopharmaceuticals

Question 60

The main advantage is that PET can illustrate _ _—including nutrient metabolism and blood flow—of the organ or organs being targeted, whereas CT and MRI scans can only show _ images.

Answer 60

Physiologic activity, static

Question 61

Ultrasonography is a technique that uses the transmission of _ _ _ into the body to generate an _ signal that is converted by a computer into a _ image of anatomy and physiology.

Answer 61

High-frequency sound waves, echo, real-time

Question 62

Ultrasonography is the least _ of all imaging techniques. The main disadvantages of ultrasonography are that the image quality is heavily _ and that it is unable to penetrate _ and _.

Answer 62

Invasive, operator-dependent, bone, gas

Question 63

The X-ray is a form of _ _ _ _ with a _ wavelength capable of penetrating solids and ionizing gases.

Answer 63

High energy electromagnetic radiation, short

Question 64

As they are used in medicine, X-rays are emitted from an X-ray machine and directed toward a specially treated _ _ placed behind the patient’s body.

Answer 64

Metallic plate

Question 65

Like many forms of high energy radiation, however, X-rays are capable of _ _ and initiating changes that can lead to _.

Answer 65

Damaging cells, cancer

Question 66

division of the anterior (ventral) cavity that houses the abdominal and pelvic viscera

Answer 66

abdominopelvic cavity

Question 67

assembly of more complex molecules from simpler molecules

Answer 67

anabolism

Question 68

standard reference position used for describing locations and directions on the human body

Answer 68

anatomical position

Question 69

science that studies the form and composition of the body’s structures

Answer 69

anatomy

Question 70

larger body cavity located anterior to the posterior (dorsal) body cavity; includes the serous membrane- lined pleural cavities for the lungs, pericardial cavity for the heart, and peritoneal cavity for the abdominal and pelvic organs; also referred to as ventral cavity

Answer 70

anterior cavity

Question 71

describes the front or direction toward the front of the body; also referred to as ventral

Answer 71

anterior

Question 72

breaking down of more complex molecules into simpler molecules

Answer 72

catabolism

Question 73

describes a position below or lower than another part of the body proper; near or toward the tail (in humans, the coccyx, or lowest part of the spinal column); also referred to as inferior

Answer 73

caudal

Question 74

smallest independently functioning unit of all organisms; in animals, a cell contains cytoplasm, composed of fluid and organelles

Answer 74

cell

Question 75

medical imaging technique in which a computer-enhanced cross-sectional X-ray image is obtained

Answer 75

computed tomography (CT)

Question 76

compares values to their normal range; deviations cause the activation of an effector

Answer 76

control center

Question 77

division of the posterior (dorsal) cavity that houses the brain

Answer 77

cranial cavity

Question 78

describes a position above or higher than another part of the body proper; also referred to as superior

Answer 78

cranial

Question 79

describes a position farther from the surface of the body

Answer 79

deep

Question 80

changes an organism goes through during its life

Answer 80

development

Question 81

process by which unspecialized cells become specialized in structure and function

Answer 81

differentiation

Question 82

describes a position farther from the point of attachment or the trunk of the body

Answer 82

distal

Question 83

posterior body cavity that houses the brain and spinal cord; also referred to the posterior body cavity

Answer 83

dorsal cavity

Question 84

describes the back or direction toward the back of the body; also referred to as posterior

Answer 84

dorsal

Question 85

organ that can cause a change in a value

Answer 85

effector

Question 86

two-dimensional, vertical plane that divides the body or organ into anterior and posterior portions

Answer 86

frontal plane

Question 87

study of the larger structures of the body, typically with the unaided eye; also referred to macroscopic anatomy

Answer 87

gross anatomy

Question 88

process of increasing in size

Answer 88

growth

Question 89

steady state of body systems that living organisms maintain

Answer 89

homeostasis

Question 90

describes a position below or lower than another part of the body proper; near or toward the tail (in humans, the coccyx, or lowest part of the spinal column); also referred to as caudal

Answer 90

inferior

Question 91

describes the side or direction toward the side of the body

Answer 91

lateral

Question 92

medical imaging technique in which a device generates a magnetic field to
obtain detailed sectional images of the internal structures of the body

Answer 92

magnetic resonance imaging (MRI)

Question 93

describes the middle or direction toward the middle of the body

Answer 93

medial

Question 94

sum of all of the body’s chemical reactions

Answer 94

metabolism

Question 95

study of very small structures of the body using magnification

Answer 95

microscopic anatomy

Question 96

homeostatic mechanism that tends to stabilize an upset in the body’s physiological condition by preventing an excessive response to a stimulus, typically as the stimulus is removed

Answer 96

negative feedback

Question 97

range of values around the set point that do not cause a reaction by the control center

Answer 97

normal range

Question 98

chemical obtained from foods and beverages that is critical to human survival

Answer 98

nutrient

Question 99

group of organs that work together to carry out a particular function

Answer 99

organ system

Question 100

living being that has a cellular structure and that can independently perform all physiologic functions necessary for life

Answer 100

organism

Question 101

functionally distinct structure composed of two or more types of tissues

Answer 101

organ

Question 102

sac that encloses the heart

Answer 102

pericardium

Question 103

serous membrane that lines the abdominopelvic cavity and covers the organs found there

Answer 103

peritoneum

Question 104

science that studies the chemistry, biochemistry, and physics of the body’s functions

Answer 104

physiology

Question 105

imaginary two-dimensional surface that passes through the body

Answer 105

plane

Question 106

serous membrane that lines the pleural cavity and covers the lungs

Answer 106

pleura

Question 107

mechanism that intensifies a change in the body’s physiological condition in response to a stimulus

Answer 107

positive feedback

Question 108

medical imaging technique in which radiopharmaceuticals are traced to reveal metabolic and physiological functions in tissues

Answer 108

positron emission tomography (PET)

Question 109

posterior body cavity that houses the brain and spinal cord; also referred to as dorsal cavity

Answer 109

posterior cavity

Question 110

describes the back or direction toward the back of the body; also referred to as dorsal

Answer 110

posterior

Question 111

force exerted by a substance in contact with another substance

Answer 111

pressure

Question 112

face down

Answer 112

prone

Question 113

describes a position nearer to the point of attachment or the trunk of the body

Answer 113

proximal

Question 114

study of the structures that contribute to specific body regions

Answer 114

regional anatomy

Question 115

process by which worn-out cells are replaced

Answer 115

renewal

Question 116

process by which new organisms are generated

Answer 116

reproduction

Question 117

ability of an organisms or a system to adjust to changes in conditions

Answer 117

responsiveness

Question 118

two-dimensional, vertical plane that divides the body or organ into right and left sides

Answer 118

sagittal plane

Question 119

in anatomy, a single flat surface of a three-dimensional structure that has been cut through

Answer 119

section

Question 120

(also, receptor) reports a monitored physiological value to the control center

Answer 120

sensor

Question 121

membrane that covers organs and reduces friction; also referred to as serous membrane

Answer 121

serosa

Question 122

membrane that covers organs and reduces friction; also referred to as serosa

Answer 122

serous membrane

Question 123

ideal value for a physiological parameter; the level or small range within which a physiological parameter such as blood pressure is stable and optimally healthful, that is, within its parameters of homeostasis

Answer 123

set point

Question 124

division of the dorsal cavity that houses the spinal cord; also referred to as vertebral cavity

Answer 124

spinal cavity

Question 125

describes a position nearer to the surface of the body

Answer 125

superficial

Question 126

describes a position above or higher than another part of the body proper; also referred to as cranial

Answer 126

superior

Question 127

face up

Answer 127

supine

Question 128

study of the structures that contribute to specific body systems

Answer 128

systemic anatomy

Question 129

division of the anterior (ventral) cavity that houses the heart, lungs, esophagus, and trachea

Answer 129

thoracic cavity

Question 130

group of similar or closely related cells that act together to perform a specific function

Answer 130

tissue

Question 131

two-dimensional, horizontal plane that divides the body or organ into superior and inferior portions

Answer 131

transverse plane

Question 132

application of ultrasonic waves to visualize subcutaneous body structures such as tendons and organs

Answer 132

ultrasonography

Question 133

larger body cavity located anterior to the posterior (dorsal) body cavity; includes the serous membrane- lined pleural cavities for the lungs, pericardial cavity for the heart, and peritoneal cavity for the abdominal and pelvic organs; also referred to as anterior body cavity

Answer 133

ventral cavity

Question 134

describes the front or direction toward the front of the body; also referred to as anterior

Answer 134

ventral

Question 135

form of high energy electromagnetic radiation with a short wavelength capable of penetrating solids and ionizing
gases; used in medicine as a diagnostic aid to visualize body structures such as bones

Answer 135

X-ray

Question 136

What kind of catabolism occurs in the heart?

Answer 136

animation (http://openstaxcollege.org/l/ metabolic)

Fatty acid catabolism

Question 137

Which organ has primary control over the amount of water in the body?

Answer 137

video (http://openstaxcollege.org/l/H2Ocon)

The kidneys

Question 138

What type of radiation does a CT scanner use?

Answer 138

video (http://openstaxcollege.org/l/CATscan)

X-rays

Question 139

What is the function of magnets in an MRI?

Answer 139

video (http://openstaxcollege.org/l/MRI)

The magnets induce tissue to emit radio signals that can show differences between different types of tissue.

Question 140

How is PET used in chemotherapy?

Answer 140

video (http://openstaxcollege.org/l/PET)

PET scans can indicate how patients are responding to chemotherapy.

Question 141

Which of the following specialties might focus on studying all of the structures of the ankle and foot ?

a. microscopic anatomy
b. muscle anatomy
c. regional anatomy
d. systemic anatomy

Answer 141

C

Question 142

A scientist wants to study how the body uses food and fluids during a marathon run. This scientist is most likely a(n) ____.

a. exercise physiologist
b. microscopic anatomist
c. regional physiologist
d. systemic anatomist

Answer 142

A

Question 143

The smallest independently functioning unit of an organism is a(n) ____.

a. cell
b. molecule
c. organ
d. tissue

Answer 143

A

Question 144

A collection of similar tissues that performs a specific function is an ___.

a. organ
b. organelle
c. organism
d. organ system

Answer 144

A

Question 145

The body system responsible for structural support and movement is the ___.

a. cardiovascular system
b. endocrine system
c. muscular system
d. skeletal system

Answer 145

D

Question 146

Metabolism can be defined as ___.

a. adjustment by an organism to external or internal changes
b. process whereby all unspecialized cells become specialized to perform distinct functions
c. process whereby new cells are formed to replace worn-out cells
d. sum of all chemical reactions in an organism

Answer 146

D

Question 147

Adenosine Triphosphate (ATP) is an important molecule because it ___.

a. is the result of catabolism
b. release energy in uncontrolled bursts
c. stores energy for use by body cells
d. all of the above

Answer 147

C

Question 148

Cancer cells can be characterized as “generic” cells that perform no specialized body function. Thus cancer cells lack ___.

a. differentiation
b. reproduction
c. responsiveness
d. both reproduction and responsiveness

Answer 148

A

Question 149

Humans have the most urgent need for a continuous
supply of ________.

a. food
b. nitrogen
c. oxygen
d. water

Answer 149

C

Question 150

Which of the following statements about nutrients is
true?

a. All classes of nutrients are essential to human
survival.
b. Because the body cannot store any micronutrients,
they need to be consumed nearly every day.
c. Carbohydrates, lipids, and proteins are
micronutrients.
d. Macronutrients are vitamins and minerals.

Answer 150

A

Question 151

C.J. is stuck in her car during a bitterly cold blizzard.
Her body responds to the cold by ________.

a. increasing the blood to her hands and feet
b. becoming lethargic to conserve heat
c. breaking down stored energy
d. significantly increasing blood oxygen levels

Answer 151

C

Question 152

After you eat lunch, nerve cells in your stomach respond
to the distension (the stimulus) resulting from the food. They
relay this information to ________.

a. a control center
b. a set point
c. effectors
d. sensors

Answer 152

A

Question 153

Stimulation of the heat-loss center causes ________.

a. blood vessels in the skin to constrict
b. breathing to become slow and shallow
c. sweat glands to increase their output
d. All of the above

Answer 153

C

Question 154

Which of the following is an example of a normal
physiologic process that uses a positive feedback loop?

a. blood pressure regulation
b. childbirth
c. regulation of fluid balance
d. temperature regulation

Answer 154

B

Question 155

What is the position of the body when it is in the “normal
anatomical position?”

a. The person is prone with upper limbs, including
palms, touching sides and lower limbs touching at
sides.
b. The person is standing facing the observer, with
upper limbs extended out at a ninety-degree angle
from the torso and lower limbs in a wide stance
with feet pointing laterally
c. The person is supine with upper limbs, including
palms, touching sides and lower limbs touching at
sides.
d. None of the above

Answer 155

D

Question 156

To make a banana split, you halve a banana into two
long, thin, right and left sides along the ________.

a. coronal plane
b. longitudinal plane
c. midsagittal plane
d. transverse plane

Answer 156

C

Question 157

The lumbar region is ________.

a. inferior to the gluteal region
b. inferior to the umbilical region
c. superior to the cervical region
d. superior to the popliteal region

Answer 157

D

Question 158

The heart is within the ________.

a. cranial cavity
b. mediastinum
c. posterior (dorsal) cavity
d. All of the above

Answer 158

B

Question 159

In 1901, Wilhelm Röntgen was the first person to win
the Nobel Prize for physics. For what discovery did he win?

a. nuclear physics
b. radiopharmaceuticals
c. the link between radiation and cancer
d. X-rays

Answer 159

D

Question 160

Which of the following imaging techniques would be
best to use to study the uptake of nutrients by rapidly
multiplying cancer cells?

a. CT
b. MRI
c. PET
d. ultrasonography

Answer 160

C

Question 161

Which of the following imaging studies can be used
most safely during pregnancy?

a. CT scans
b. PET scans
c. ultrasounds
d. X-rays

Answer 161

C

Question 162

What are two major disadvantages of MRI scans?

a. release of radiation and poor quality images
b. high cost and the need for shielding from the
magnetic signals
c. can only view metabolically active tissues and
inadequate availability of equipment
d. release of radiation and the need for a patient to be
confined to metal tube for up to 30 minutes

Answer 162

B

Question 163

Name at least three reasons to study anatomy and
physiology.
An understanding of anatomy and physiology is essential for _ _ in the health professions. It can also help you make choices that promote your _, respond appropriately to signs of _, make sense of health-related _, and help you in your roles as a parent, spouse, partner, friend, colleague, and caregiver.

Answer 163

Any career, health, illness, news

Question 164

For whom would an appreciation of the structural
characteristics of the human heart come more easily: an alien who lands on Earth, abducts a human, and dissects his heart, or an anatomy and physiology student performing a dissection of the heart on her very first day of class? Why?
A student would more readily appreciate the structures revealed in the . Even though the student has not yet studied the workings of the heart and blood vessels in her class, she has experienced her heart beating every moment of her life, has probably felt her pulse, and likely has at least a basic understanding of the role of the heart in pumping blood throughout her body. This understanding of the heart’s function () would support her study of the heart’s form (_).

Answer 164

Dissection, physiology, anatomy

Question 165

Name the six levels of organization of the human body.

Answer 165

1. Chemical
2. Cellular
3. Tissue
4. Organ
5. Organ system
6. Organism

Question 166

The female ovaries and the male testes are a part of
which body system? Can these organs be members of more than one organ system? Why or why not?
The female ovaries and the male testes are parts of the _ system. But they also _ _, as does the _ system, therefore ovaries and testes function within both the _ and _ systems

Answer 166

Reproductive, secrete hormones, endocrine, endocrine, reproductive

Question 167

Explain why the smell of smoke when you are sitting
at a campfire does not trigger alarm, but the smell of smoke in your residence hall does.
When you are sitting at a campfire, your sense of smell _ to the smell of smoke. Only if that smell were to suddenly and dramatically _ would you be likely to notice and respond. In contrast, the smell of even a trace of smoke would be new and highly unusual in your residence hall, and would be perceived as _.

Answer 167

Adapts, intensify, danger

Question 168

Identify three different ways that growth can occur in the human body.
Growth can occur by increasing the _ of existing cells, increasing the _ of existing cells, or increasing the amount of _ _ around cells.

Answer 168

Number, size, non-cellular material

Question 169

When you open a bottle of sparkling water, the carbon dioxide gas in the bottle form bubbles. If the bottle is left open, the water will eventually “go flat.” Explain these phenomena in terms of atmospheric pressure.
In a sealed bottle of sparkling water, carbon dioxide gas is kept _ in the water under a very _ pressure. When you open the bottle, the pressure of the gas above the liquid changes from artificially _ to _ atmospheric pressure. The dissolved carbon dioxide gas _, and rises in bubbles to the surface. When a bottle of sparkling water is left open, it eventually goes flat because its gases continue to move _ of solution until the pressure in the water is approximately _ to atmospheric pressure.

Answer 169

Dissolved, high, high, normal, expands, out, equal

Question 170

On his midsummer trek through the desert, Josh ran out of water. Why is this particularly dangerous?
The primary way that the body responds to high environmental heat is by _; however, it requires _, which comes from body fluids, including blood plasma. If Josh becomes dehydrated, he will be unable to _ _ to cool his body, and he will be at risk for _ _ as his _ _ drops too much from the loss of water from the blood plasma.

Answer 170

Sweating, water, sweat adequately, heat stroke, blood pressure

Question 171

Identify the four components of a negative feedback loop and explain what would happen if secretion of a body chemical controlled by a negative feedback system became too great.
The four components of a negative feedback loop are: _, _, _ _, and _. If too great a quantity of the chemical were excreted, sensors would activate a _ _, which would in turn activate an _. In this case, the effector (the secreting cells) would be adjusted downward.

Answer 171

Stimulus, sensor, control center, effector, control center, effector

Question 172

What regulatory processes would your body use if
you were trapped by a blizzard in an unheated, uninsulated cabin in the woods?
Any prolonged exposure to extreme cold would activate the brain’s _ _. This would reduce _ _ to your skin, and shunt _ _ from your limbs away from the digits and into a network of deep veins. Your brain’s heat-gain center would also _ your muscle contraction, causing you to shiver. This increases the _ _ of skeletal muscle and generates more heat. Your body would also produce _ _ and _, chemicals that promote increased _ and _ _.

Answer 172

Heat-gain center, blood flow, blood returning, increase, energy consumption, thyroid hormone, epinephrine, metabolism, heat production

Question 173

In which direction would an MRI scanner move to
produce sequential images of the body in the frontal plane, and in which direction would an MRI scanner move to produce sequential images of the body in the sagittal plane?
If the body were supine or prone, the MRI scanner would move from _ to _ to produce frontal sections, which would divide the body into _ and _ portions, as in “cutting” a deck of cards. Again, if the body were supine or prone, to produce sagittal sections, the scanner would move from _ to _ to divide the body lengthwise into left and right portions.

Answer 173

Top, bottom, anterior, posterior, left, right,

Question 174

If a bullet were to penetrate a lung, which three anterior thoracic body cavities would it enter, and which layer of the serous membrane would it encounter first?
The bullet would enter the _, _, and _ _, and it would encounter the _ layer of serous membrane first.

Answer 174

Ventral, thoracic, pleural cavities, parietal

Question 175

Which medical imaging technique is most dangerous to use repeatedly, and why?
_ scanning subjects patients to much _ levels of radiation than _, and should not be performed repeatedly.

Answer 175

CT, higher, X-rays

Question 176

Explain why ultrasound imaging is the technique of
choice for studying fetal growth and development.
Ultrasonography does not expose a mother or fetus to _, to _, or to _ _. At this time, there are no known medical risks of ultrasonography.

Answer 176

Radiation, radiopharmaceuticals, magnetic fields