Chapter 1: The Anatomy and Physiology of the Respiratory System

TRUE/FALSE

	1.	The palatine tonsils and the pharyngeal tonsils are thought to be types of lymphoid tissues.

ANS:	T

	Feedback	
Correct	The palatine and pharyngeal tonsils are lymphoid tissues and are believed to serve certain immunologic defense functions.	
Incorrect	The palatine and pharyngeal tonsils are lymphoid tissues and are believed to serve certain immunologic defense functions.	

PTS:	1

	2.	The eustachian tubes serve to equalize pressure in the middle ear.

ANS:	T

	Feedback	
Correct	The eustachian tubes connect the nasopharynx to the middle ear and serve to equalize pressure in the middle ear.	
Incorrect	The eustachian tubes connect the nasopharynx to the middle ear and serve to equalize pressure in the middle ear.	

PTS:	1

	3.	The oropharynx is located between the hard palate, superiorly, and the base of the tongue, inferiorly.

ANS:	F

	Feedback	
Correct	The oropharynx is located between the soft palate, superiorly, and the base of the tongue, inferiorly.	
Incorrect	The oropharynx is located between the soft palate, superiorly, and the base of the tongue, inferiorly.	

PTS:	1

	4.	The pharyngeal reflex is also known as the swallowing reflex.

ANS:	T

	Feedback	
Correct	When stimulated, the muscles and nerves work together to produce the pharyngeal reflex, also known as the gag or swallowing reflex.	
Incorrect	When stimulated, the muscles and nerves work together to produce the pharyngeal reflex, also known as the gag or swallowing reflex.	

PTS:	1

	5.	An endotracheal tube is used to bypass the lower airway.

ANS:	F

	Feedback	
Correct	An endotracheal tube is used to bypass the upper airway and must be appropriately warmed and humidified.	
Incorrect	An endotracheal tube is used to bypass the upper airway and must be appropriately warmed and humidified.	

PTS:	1

	6.	The visceral pleura is attached to the inner surface of the lungs.

ANS:	F

	Feedback	
Correct	The visceral pleura is attached to the outer surface of each lung. The parietal pleura lines the inside of the thoracic walls.	
Incorrect	The visceral pleura is attached to the outer surface of each lung. The parietal pleura lines the inside of the thoracic walls.	

PTS:	1

	7.	The lungs have a natural tendency to collapse.

ANS:	T

	Feedback	
Correct	The lungs have a natural tendency to collapse, and the thorax has a natural tendency to expand.	
Incorrect	The lungs have a natural tendency to collapse, and the thorax has a natural tendency to expand.	

PTS:	1

	8.	The thorax has a natural tendency to expand.

ANS:	T

	Feedback	
Correct	The thorax has a natural tendency to expand, and the lungs have a natural tendency to collapse.	
Incorrect	The thorax has a natural tendency to expand, and the lungs have a natural tendency to collapse.	

PTS:	1

	9.	Twelve thoracic vertebrae form the posterior midline border of the thoracic cage.

ANS:	T

	Feedback	
Correct	Twelve thoracic vertebrae form the posterior midline border of the thoracic cage.	
Incorrect	Twelve thoracic vertebrae form the posterior midline border of the thoracic cage.	

PTS:	1

	10.	The anterior tendon is the area where the two hemidiaphragms merge together.

ANS:	F

	Feedback	
Correct	The two hemidiaphragms merge in an area called the central tendon.	
Incorrect	The two hemidiaphragms merge in an area called the central tendon.	

PTS:	1

	11.	The purpose of cilia is to propel mucus toward the nasopharynx.

ANS:	T

	Feedback	
Correct	The purpose of cilia is to propel mucus toward the nasopharynx.	
Incorrect	The purpose of cilia is to propel mucus toward the nasopharynx.	

PTS:	1

	12.	The receptors for sense are located in the olfactory region.

ANS:	T

	Feedback	
Correct	The receptors for sense are located in the olfactory region.	
Incorrect	The receptors for sense are located in the olfactory region.	

PTS:	1

MULTIPLE CHOICE

	1.	Which of the following is not a primary function of the upper airway?
a.	to humidify and warm inspired air	
b.	to help with speech and smell	
c.	to conduct air	
d.	to house the teeth	

ANS:	D

	Feedback	
A	The primary functions of the upper airway are to conduct air, to humidify and warm inspired air, to prevent foreign materials from entering the tracheobronchial tree, and to serve as an important part of smell and speech.	
B	The primary functions of the upper airway are to conduct air, to humidify and warm inspired air, to prevent foreign materials from entering the tracheobronchial tree, and to serve as an important part of smell and speech.	
C	The primary functions of the upper airway are to conductor air, to humidify and warm inspired air, to prevent foreign materials from entering the tracheobronchial tree, and to serve as an important part of smell and speech.	
D	The teeth are housed in the oral cavity, not the upper airway.	

PTS:	1

	2.	What forms the floor of the nasal cavity?
a.	the palatine process of the maxilla and the palatine bones	
b.	the frontal process of the maxilla and the cribriform plate of the ethmoid bone	
c.	the vomer and the perpendicular plate of the ethmoid bone	
d.	the hard and soft palates of the roof of the mouth	

ANS:	A

	Feedback	
A	The palatine process of the maxilla and the palatine bones create the floor of the nasal cavity. These also form the hard palate of the roof of the mouth.	
B	The frontal process of the maxilla and the cribriform plate of the ethmoid bone form the roof of the nasal cavity.	
C	The vomer and the perpendicular plate of the ethmoid bone form the posterior nasal septum.	
D	The hard palate forms the floor of the nasal cavity, but the soft palate does not.	

PTS:	1

	3.	What part of the nose represents the tracheobronchial tree’s first line of defense?
a.	nostrils	
b.	vibrissae	
c.	stratified squamous epithelium (nonciliated)	
d.	vestibule	

ANS:	B

	Feedback	
A	The nostrils are where air first enters the nasal cavity.	
B	Vibrissae, or hair follicles, are housed in the vestibule of the nose and are the first line of defense.	
C	Nonciliated stratified squamous epithelium lines the anterior one-third of the nasal cavity but plays no role in the tracheobronchial tree’s first line of defense.	
D	The vestibule houses the vibrissae but in itself plays no role in the tracheobronchial tree’s first line of defense.	

PTS:	1

	4.	What type of epithelium lines the oral cavity?
a.	nonciliated pseudostratified columnar epithelium	
b.	nonciliated stratified squamous epithelium	
c.	ciliated pseudostratified columnar epithelium	
d.	ciliated stratified squamous epithelium	

ANS:	B

	Feedback	
A	Nonciliated pseudostratified columnar epithelium does not line any part of the airway. 	
B	Nonciliated stratified squamous epithelium lines the anterior third of the nasal cavity, the oral cavity, the oropharynx, and the area above the vocal cords.	
C	Ciliated pseudostratified columnar epithelium lines the posterior two-thirds of the nasal cavity, the nasopharynx, and the area below the vocal cords.	
D	Ciliated stratified squamous epithelium does not line any part of the airway.	

PTS:	1

	5.	What is the area between the base of the tongue and the epiglottis called?
a.	Adam’s apple	
b.	thyroid cartilage	
c.	hyoid bone	
d.	vallecula	

ANS:	D

	Feedback	
A	The Adam’s apple is another name for the thyroid cartilage.	
B	Another name for the thyroid cartilage is the Adam’s apple.	
C	The hyoid bone is not part of the larynx and is a horseshoe-shaped bone that is suspended from the upper portion of the thyroid cartilage.	
D	The vallecula is formed by mucous membrane folds between the base of the tongue and the epiglottis.	

PTS:	1

	6.	Alveolar type II cells produce what substance?
a.	mucus	
b.	pulmonary surfactant	
c.	antibodies	
d.	saliva	

ANS:	B

	Feedback	
A	Mucus is produced by goblet cells and bronchial glands.	
B	Alveolar type II cells produce surfactant, which decreases surface tension.	
C	Antibodies are produced when an antigen is introduced to the body. They are not produced by alveolar type II cells.	
D	Saliva is produced by salivary glands in the oral cavity.	

PTS:	1

	7.	What does the stimulated sympathetic nervous system cause to occur in the bronchial smooth muscle?
a.	bronchoconstriction	
b.	vasodilation	
c.	bronchodilation	
d.	vasoconstriction	

ANS:	C

	Feedback	
A	Sympathetic nervous system stimulation causes the bronchial smooth muscle to dilate not constrict.	
B	The prefix vaso- means “vessel”; the term vasodilation means “blood vessels dilate.” 	
C	The sympathetic nervous system is the fight-or-flight system and causes bronchodilation to prepare the body for action.	
D	The term vaso- means “vessel”; the term vasoconstriction means “blood vessels constrict.”	

PTS:	1

	8.	Anteriorly, the base of the lungs extends down to approximately where?
a.	eleventh rib	
b.	base of the scapula	
c.	sixth rib	
d.	body of the manubrium	

ANS:	C

	Feedback	
A	The base of the lung extends to the eleventh rib, posteriorly.	
B	The scapula is on the posterior side of the thorax.	
C	Anteriorly, the base of the lung extends to the sixth rib, or the level of the xiphoid process.	
D	The manubrium does not extend down far enough.	

PTS:	1

	9.	What nerve innervates each hemidiaphragm?
a.	optic	
b.	facial	
c.	glossopharyngeal	
d.	phrenic	

ANS:	D

	Feedback	
A	The optic nerve innervates the eye.	
B	The facial nerve innervates the muscles of the face.	
C	The glossopharyngeal nerve innervates the posterior third of the tongue.	
D	The phrenic nerve innervates each hemidiaphragm, which causes diaphragmatic contraction.	

PTS:	1

	10.	Which of the following does not slow the rate of mucociliary transport?
a.	humidity	
b.	cigarette smoke	
c.	hypoxia	
d.	dehydration	

ANS:	A

	Feedback	
A	Proper humidity will increase the rate of the mucociliary transport.	
B	Cigarette smoke will decrease the rate of mucociliary transport.	
C	Hypoxia will decrease the rate of mucociliary transport.	
D	Dehydration will decrease the rate of mucociliary transport.	

PTS:	1

	11.	The bifurcation of the trachea is known as the:
a.	hilum	
b.	carina	
c.	aortic arch	
d.	glottis	

ANS:	B

	Feedback	
A	The hilum is the area of the lung where the blood vessels, nerves, lymph vessels, and main stem bronchi enter and exit the lungs.	
B	The carina is the bifurcation of the trachea into the right and left main stem bronchi.	
C	The aortic arch is where the aorta leaves the heart and turns downward and to the left, creating an arch.	
D	The glottis is the opening between the true vocal cords.	

PTS:	1

	12.	Approximately, how many alveoli are in one primary lobule?
a.	2000	
b.	130,000	
c.	300 million	
d.	20	

ANS:	A

	Feedback	
A	There are about 2000 alveoli in each primary lobule.	
B	There are about 130,000 primary lobules in the lung.	
C	An average adult male has about 300 million alveoli in the lung.	
D	There are between 15 and 20 alveolar sacs for each alveolar duct.	

PTS:	1

	13.	What is the purpose of the vibrissae?
a.	to filter the inspired air	
b.	to warm the filtered air	
c.	to humidify the filtered air	
d.	to clean the inspired air	

ANS:	A

	Feedback	
A	The vibrissae filter inspired air.	
B	The vibrissae filter inspired air.	
C	The vibrissae filter inspired air.	
D	The vibrissae filter inspired air.	

PTS:	1

	14.	What type of epithelium lines the anterior one-third of the nasal cavity?
a.	stratified squamous 	
b.	pseudostratified ciliated	
c.	stratified nonciliated	
d.	columnar	

ANS:	A

	Feedback	
A	Stratified squamous epithelium lines the anterior one-third of the nasal cavity.	
B	Stratified squamous epithelium lines the anterior one-third of the nasal cavity.	
C	Stratified squamous epithelium lines the anterior one-third of the nasal cavity.	
D	Stratified squamous epithelium lines the anterior one-third of the nasal cavity.	

PTS:	1

	15.	What type of epithelium lines the posterior two-thirds of the nasal cavity?
a.	pseudostratified squamous	
b.	pseudostratified ciliated columnar	
c.	ciliated squamous	
d.	nonciliated columnar	

ANS:	B

	Feedback	
A	Pseudostratified ciliated columnar epithelium lines the posterior two-thirds of the nasal cavity.	
B	Pseudostratified ciliated columnar epithelium lines the posterior two-thirds of the nasal cavity.	
C	Pseudostratified ciliated columnar epithelium lines the posterior two-thirds of the nasal cavity.	
D	Pseudostratified ciliated columnar epithelium lines the posterior two-thirds of the nasal cavity.	

PTS:	1

MULTIPLE RESPONSE

	1.	Which of the following is/are function(s) of the larynx?
a.	It is a passageway for air between the pharynx and the trachea.	
b.	It helps with the sense of smell.	
c.	It helps protect against aspiration.	
d.	It helps with phonation.	

ANS:	A, C, D

	Feedback	
Correct	The larynx is a passageway for air between the pharynx and the trachea, it helps protect against aspiration, and it helps with phonation.	
Incorrect	The upper airway is involved with the sense of smell; the larynx is not.	

PTS:	1

	2.	Which of the following represent the single cartilages of the larynx?
a.	corniculate	
b.	thyroid	
c.	epiglottis	
d.	cricoid	

ANS:	B, C, D

	Feedback	
Correct	The thyroid cartilage, the epiglottis, and the cricoid cartilage are all single cartilages of the larynx.	
Incorrect	The corniculate cartilage is a paired cartilage.	

PTS:	1

	3.	Which of the following produces mucus in the tracheobronchial tree?
a.	lamina propria	
b.	goblet cells	
c.	submucosal, or bronchial, glands	
d.	basement membrane	

ANS:	B, C

	Feedback	
Correct	Goblet cells and submucosal, or bronchial, glands produce mucus, but the bronchial glands produce the majority of the mucus in the tracheobronchial tree.	
Incorrect	The lamina propria is part of the epithelial layer of the tracheobronchial tree and is where the submucosal glands are located. The basement membrane is part of the epithelial layer of the tracheobronchial tree and separates the basal cells from the smooth muscle.	

PTS:	1

	4.	When a mast cell degranulates, which of the following is released?
a.	histamine	
b.	IgE	
c.	SRS-A	
d.	antigen	

ANS:	A, C

	Feedback	
Correct	Histamine, SRS-A, heparin, PAF, and ECF-A are some of the chemical mediators that are released from a mast cell when it degranulates.	
Incorrect	IgE is the substance that binds to the mast cell. An antigen is the foreign substance that causes IgE to be released.	

PTS:	1

	5.	Which of the following are included in the cartilaginous airways?
a.	terminal bronchi	
b.	segmental bronchi	
c.	lobar bronchi	
d.	trachea	

ANS:	B, C, D

	Feedback	
Correct	The trachea, main stem bronchi, lobar bronchi, segmental bronchioles, and subsegmental bronchioles contain cartilage and are therefore considered cartilaginous airways.	
Incorrect	The terminal bronchioles are noncartilaginous airways.	

PTS:	1

	6.	What are the names of the two airways that make up the noncartilaginous airways?
a.	alveolar ducts	
b.	bronchioles	
c.	subsegmental airways	
d.	terminal bronchioles	

ANS:	B, D

	Feedback	
Correct	The bronchioles and the terminal bronchioles are noncartilaginous.	
Incorrect	The alveolar ducts are part of the area for gas exchange. The subsegmental airways are part of the cartilaginous airways.	

PTS:	1

	7.	A primary lobule is composed of which of the following?
a.	respiratory bronchioles	
b.	alveolar ducts	
c.	terminal bronchioles	
d.	alveolar clusters	

ANS:	A, B, D

	Feedback	
Correct	A primary lobule is composed of the respiratory bronchioles, alveolar ducts, and alveolar clusters that originate from a single terminal bronchiole.	
Incorrect	The terminal bronchioles are not part of the sites for gas exchange but are part of the noncartilaginous airways.	

PTS:	1

	8.	Which of the following are part of the layers of the arteries?
a.	tunica intima	
b.	tunica media	
c.	tunica adventitia	
d.	tunica outer	

ANS:	A, B, C

	Feedback	
Correct	The tunica intima is the innermost layer, the tunica media is the middle layer, and the tunica adventitia is the outer layer of an artery.	
Incorrect	There is no term tunica outer.	

PTS:	1

	9.	Which of the following are accessory muscles of expiration?
a.	trapezius 	
b.	pectoralis major 	
c.	internal intercostal 	
d.	rectus abdominis 	

ANS:	C, D

	Feedback	
Correct	The rectus abdominis, external abdominis obliquus, internal abdominis obliquus, transversus abdominis, and internal intercostal muscles are accessory muscles of expiration.	
Incorrect	The trapezius, pectoralis major, scalene, sternocleidomastoid, and external intercostal muscles are muscles of inspiration.	

PTS:	1

	10.	What are the names of the areas that make up the pharynx?
a.	oropharynx	
b.	nasopharynx	
c.	laryngopharynx	
d.	oral cavity	

ANS:	A, B, C

	Feedback	
Correct	The oropharynx, nasopharynx, and laryngopharynx make up the pharynx.	
Incorrect	The oral cavity is the area located anteriorly to the oropharynx.	

PTS:	1

	11.	You are called to assess a patient who has increased work of breathing (WOB) on inspiration. You could expect to see what accessory muscles being used?
a.	trapezius	
b.	rectus abdominis	
c.	external oblique	
d.	pectoralis major	

ANS:	A, D

	Feedback	
Correct	The trapezius, pectoralis major, sternocleidomastoid, scalene, and external intercostal muscles are accessory muscles of inspiration.	
Incorrect	The rectus abdominis, external abdominis obliquus, internal abdominis obliquus, transversus, and internal intercostal muscles are accessory muscles of expiration.	

PTS:	1

	12.	What three parts compose the sternum?
a.	clavicle	
b.	xiphoid process	
c.	body of sternum	
d.	manubrium	

ANS:	B, C, D

	Feedback	
Correct	The manubrium is the top part of the sternum. The body of the sternum is the middle and largest part of the sternum. The xiphoid process is the small projection of bone at the bottom of the sternum.	
Incorrect	The clavicle attaches to the manubrium of the sternum.	

PTS:	1

	13.	What two layers make up the mucous blanket?
a.	cilia	
b.	gel	
c.	sol	
d.	basal cells	

ANS:	B, C

	Feedback	
Correct	The gel layer is the top layer and more viscous; the sol layer is the bottom layer.	
Incorrect	The cilia move the sol layer in a wavelike fashion. The cilia are attached to the basal cells.	

PTS:	1

	14.	Which of the following make up the cartilaginous airways?
a.	subsegmental bronchi	
b.	segmental bronchi	
c.	main stem bronchi	
d.	lobar bronchi	

ANS:	A, B, C, D

	Feedback	
Correct	All of the answers are part of the cartilaginous airways.	
Incorrect	There are no incorrect answers for this question.	

PTS:	1

	15.	Which of the following make up the noncartilaginous airways?
a.	trachea	
b.	bronchioles	
c.	respiratory bronchioles	
d.	terminal bronchioles	

ANS:	B, D

	Feedback	
Correct	The bronchioles and terminal bronchioles make up the noncartilaginous airways.	
Incorrect	The trachea is part of the cartilaginous airways, and the respiratory bronchioles are part of the sites of gas exchange.	

PTS:	1

	16.	Which of the following are part of the sites of gas exchange?
a.	alveolar sacs	
b.	alveolar ducts	
c.	bronchioles	
d.	respiratory bronchioles	

ANS:	A, B, D

	Feedback	
Correct	The alveolar sacs, alveolar ducts, and the respiratory bronchioles are part of the sites of gas exchange.	
Incorrect	The bronchioles are noncartilaginous airways.	

PTS:	1

	17.	What forms the roof of the nasal cavity?
a.	nasal bones	
b.	palatine bones	
c.	frontal process of the maxilla	
d.	cribriform plate of the ethmoid bone	

ANS:	A, C, D

	Feedback	
Correct	The nasal bones, frontal process of the maxilla, and the cribriform plate of the ethmoid bone form the roof of the nasal cavity.	
Incorrect	The palatine bones form the floor of the nasal cavity.	

PTS:	1

	18.	What forms the upper third of the nose?
a.	cribriform plate of the ethmoid bone	
b.	lateral nasal cartilage	
c.	nasal bones	
d.	frontal process of the maxilla	

ANS:	C, D

	Feedback	
Correct	The nasal bones and the frontal process of the maxilla form the upper third of the nose.	
Incorrect	The cribriform plate of the ethmoid bone and the lateral nasal cartilage do not make up the upper third of the nose.	

PTS:	1

COMPLETION

	1.	There are ____________________ lobes in the right lung.

ANS:	
three
3

PTS:	1

	2.	The space between the true vocal cords is called the ____________________.

ANS:	glottis

PTS:	1

	3.	The potential space between the parietal and visceral pleura is called the ______________________________.

ANS:	pleural space

PTS:	1

	4.	The ____________________ muscles allow people to shrug their shoulders and are considered accessory muscles of inspiration.

ANS:	trapezius

PTS:	1

	5.	The ____________________ fissure separates the left upper lobe from the left lower lobe.

ANS:	oblique

PTS:	1

	6.	The ____________________ is the area of the mediastinal border where the main stem bronchi, blood vessels, lymph vessels, and various nerves enter and leave the lungs.

ANS:	hilum

PTS:	1

	7.	No lymphatic vessels are found in the walls of the ____________________.

ANS:	alveoli

PTS:	1

	8.	The capillaries are composed of a single layer of ____________________ epithelial cells.

ANS:	squamous

PTS:	1

	9.	______________________________ are small holes in the walls of the interalveolar septa that permit air to pass between adjacent alveoli.

ANS:	Pores of Kohn

PTS:	1

	10.	The end of the endotracheal tube should be positioned ____________________ cm above the carina.

ANS:	
two
2

PTS:	1

	11.	If an endotracheal tube is inserted too far into the trachea, it will most likely enter the ____________________ main stem bronchi.

ANS:	right

PTS:	1

	12.	There are approximately ___________________________________ alveoli in an adult male lung.

ANS:	
300,000,000
300 million
three hundred million

PTS:	1

	13.	The ____________________ arteries arise from the aorta and nourish the tracheobronchial tree as far as the terminal bronchioles.

ANS:	bronchial

PTS:	1

	14.	About one-third of bronchial venous blood returns to the right atrium via the ____________________ vein, the ____________________ vein, and the ____________________ vein.

ANS:	
azygos, hemiazygos, intercostal
azygos, intercostal, hemiazygos
hemiazygos, azygos, intercostal
hemiazygos, intercostal, azygos
intercostal, azygos, hemiazygos
intercostal, hemiazygos, azygos

PTS:	1

	15.	As air travels down the tracheobronchial tree, the total cross-sectional area ____________________.

ANS:	increases

PTS:	1

	16.	There are about ____________________ cilia per ciliated cell.

ANS:	
200
two hundred

PTS:	1

	17.	The average diameter of the terminal bronchioles is about ____________________ mm.

ANS:	
0.5
one-half
one half
1/2

PTS:	1

	18.	In the internal portion of the nose, a partition, the ______________________________, separates the nasal cavity into two approximately equal chambers.

ANS:	nasal septum

PTS:	1

	19.	The openings of the nasal cavity, in which air flows into the nasal cavity, are called ____________________.

ANS:	
nares
nostrils

PTS:	1

	20.	As air passes through the nares, it passes through a slightly dilated area called the ____________________.

ANS:	vestibule

PTS:	1

SHORT ANSWER

	1.	List the ten branches of the tracheobronchial tree in order.

ANS:	
trachea
main stem bronchi
lobar bronchi
segmental bronchi
subsegmental bronchi
bronchioles
terminal bronchioles
respiratory bronchioles
alveolar ducts
alveolar sacs

PTS:	1

	2.	Explain what happens when a mast cell is activated.

ANS:	
When a mast cell is activated, it releases numerous substances, such as histamine, SRS-A, heparin, PAF, and ECF-A. These chemicals cause increased vascular permeability, smooth muscle contraction, increased mucus secretion, and vasodilation with edema.

PTS:	1

	3.	Explain what the alveolar-capillary interstitium is composed of?

ANS:	
The interstitium is a gel-like substance composed of molecules that are held together by a weblike network of collagen fibers. The interstitium has two major components, the tight space and the loose space. The tight space is the area between the alveolar epithelium and the capillaries. This is where gas exchange occurs. The loose space is the areas that surrounds the bronchioles, respiratory bronchioles, alveolar ducts, and alveolar sacs.

PTS:	1

	4.	What happens to the bronchial smooth muscle when the sympathetic nervous system is stimulated?

ANS:	
The bronchial smooth muscles dilate or relax when the sympathetic nervous system is stimulated.

PTS:	1

	5.	List and explain the parts of the sternum.

ANS:	
There are three parts of the sternum: the body, which is the middle portion; the xiphoid process, which is the small piece of bone at the bottom of the sternum; and the top part, which is called the manubrium sterni.

PTS:	1