Download BIO 161 Worksheet - Respiratory - Answers

BIO 161 – Respiratory - Answers
T Dic Charge – Winter 2008
Review Worksheet
1) Can you name, in order, the major structures by which air passes as it makes its way
into the lungs (that is, all the way to the alveoli)?
Nostrils – Nasal cavity – Pharynx (naso-, oro-, pharyngo-), larynx, trachea,
bronchi (primary, secondary, tertiary), bronchioles (primary, terminal,
respiratory), alveoli
2) The structures known as the nasal conchae are found in the nasal cavity. What
functions do they perform?
These scroll-like folds increase surface area and turbulence of inspired air and
therefore increase
trapping of particulate matter in inspired air
humidification of inspired air
warming of inspired air
3) What are the three pairs of salivary glands called, and where are they found?
Parotid glands – found anterior to the ear on the lateral surface of the face.
Sublingual glands – found inferior to the tongue at its base, where it attaches to
the floor of the mouth.
Submandibular glands – found below the mandible lateral to the sublingual
glands.
4) The junction at which the trachea divides into the primary bronchi is called what?
The carina
5) The epithelial layer lining the sinuses, the nasal cavity, the pharynx, the trachea, and
the bronchi is what kind of epithelium?
Pseudostratified ciliated columnar epithelium
6) Name all the paranasal cavities (sinuses), in order from largest to smallest.
Maxillary – 10-20 ml
Sphenoid – 7-9 ml
Frontal – 6-7 ml
Ethmoid –
Did you know? The ethmoid and maxillary sinuses are the first to develop and
are visible even in newborns, but that the sphenoid sinuses don’t develop until
about the age of six, and the frontal sinuses are not fully developed until about
the age of 12. Their communication with the nasal cavity is also incomplete until
those ages.
7) What is the connection from the nasal cavity to the larynx called and what 3 divisions
exist? In each division, what normally is expected to travel in that tube?
The pharynx is a funnel-shaped tube running from the back of the nasal cavity
past the opening of the oral cavity and down to the top of the larynx. Each
region is named according to the adjacent structure. The nasopharynx usually
only carries respiratory gasses. The oropharynx usually carries both food and
water and the respiratory gasses, as does the laryngopharynx.
8) The pharyngotympanic tubes connect what two places in the head? What is their
purpose? What 2 other names are they known by?
Also known as the Eustachian tubes or simply the auditory tubes, they connect
the middle ear to the nasopharynx and thus allow the equilibration of the
pressure in the middle ear with that outside the tympanic membrane.
9) Name 4 cartilages and 3 purposes of the larynx?
From largest to smallest, the cartilages are the thyroid, cricoid, arytenoid, and
the corniculate cartilages. The 3 purposes of the larynx are:
To provide the voice
To separate food and water from air (this includes protection to the glottis so
that food does not usually enter the trachea)
To provide a patent airway
10) What is the epiglottis? How does swallowing work?
The epiglottis is a flap of elastic cartilage that is depressed by food as it is
swallowed, covering the glottis and preventing food from entering the airways.
In swallowing, the larynx is lifted by muscles attached to the hyoid bone
superiorly, and moved slightly anteriorly to better ensure that the epiglottis fully
blocks the entrance to the larynx. See this link for a good diagrammatic movie:
http://www.linkstudio.info/images/portfolio/medani/Swallow.swf
11) Can you label the following diagram of the larynx? A-D are cartilages, the rest are
other structures you should know.
A Thyroid Cartilage
E Hyoid Bone
B Cricoid Cartilage
C Corniculate Cartilage
D Arytenoid Cartilage
F Epiglottis
G Vocal cords
H Trachea or tracheal cartilage
12) How is the voice produced and what causes changes in pitch and in loudness?
The glottis is opened partially so that expired air causes the vocal chords to
vibrate. By tightening the chords using laryngeal muscles attached to the
arytenoids cartilages, pitch is increased/elevated (sound note gets higher).
Volume/loudness is adjusted by how much air is allowed/forced out of the lungs
via the glottis.
13) Identify all of the branches of the respiratory tree from the trachea down to the alveoli
in the alveolar sacs. For this tree, identify what part is the conducting zone (define
conducting zone) and what part is the respiratory zone (define). Indicate what the
endothelial layer tissue type is at each level of branching and whether cartilage is
present.
Trachea divides at the carina into the 2 main/primary bronchi, 1 each to the left
and right lungs. The primary bronchi branch into the secondary bronchi as
each enters a lobe of the lung – left has 2 secondary bronchi to two lobes, right
has 3 secondary bronchi to three lobes. Secondary branch into tertiary bronchi,
which then divide into primary and then terminal bronchioles. Cartilage is
present up until the level of the primary bronchioles fall below about 1mm in
diameter, at which point it disappears. Up to and including the 2nd (terminal)
level of bronchioles, PSCCE (Pseudostratified Ciliated columnar epithelium) is
the endothelial layer, and this marks the end of the conducting zone (carries
gases into/out of the lungs, without incurring any gas exchange with the blood).
Beyond this point, we are in the respiratory zone (gas exchange can/does occur –
defined by presence of alveoli) and we have simple cuboidal epithelium in the
tubes and simple squamous (diffusion of resp. gases) and cuboidal (secretion of
surfactant) in the alveoli. Terminal bronchioles branch into respiratory
bronchioles, which branch to alveolar ducts (both support sparse alveoli) and
then terminate in alveolar sacs (a cluster of alveoli).
14) For the secondary bronchi, indicate the count on both sides of the thoracic cavity and
indicate why this count is so (as in, what does the count of these airways match as far
as lung structure?).
3 right – into 3 lobes (1 EACH)
2 left – into 2 lobes (1 EACH)
15) Please place the following labels on the diagram of the lungs below.
Hilum, Apex, Costal surface, Cardiac notch, Base. As well, please draw and label
both sides of a pleural sac on the diagram, and indicate where the pleural cavity is
found.
as per your notes – the pleural cavity lies between the visceral (on the organ) and
the parietal (towards the cavity walls) pleura.
16) Describe 3 changes in lung function that are a result of aging.
Kyphosis – curvature of the spine may reduce respiratory volume
Osteoporosis - calcification of cartilage reduces compliance (flexibility) of chest
wall
Respiratory muscles weaken
decreasing elastin reduces compliance of lung and it’s recoil
alveoli increase in size - reduces the surface area to volume ratio
# of cilia reduced
# of macrophages reduced
17) What is RDS (a.k.a. HMD)?
Respiratory Distress Syndrome (Hyaline Membrane Disease) represents damage
done to the lung tissues by mechanical ventilation (use of a ventilator).
Lungs are less compliant and harder to inflate, causing respiratory distress of
the newborn
18) What two areas of the brainstem are responsible for control of respiration? Name the
areas within each, and indicate how they control respiration. Could you label a
diagram?
Pons
apneustic area increases inspiration
pneumotaxic area decreases inspiration
Medulla Ventral respiratory group (VRG) – moderates forceful inspiration
and expiration by influencing changes in DRG
Dorsal respiratory group (DRG) – regulates normal/relaxed breathing
– pacemaker
19) What are the three areas of chemoreception in the body with regard to respiration,
where are they located, and to what chemistry to they respond? What change results
from the changes they detect?
Central chemoreceptors – in medulla adjacent to VRG - respond to rising CO2
indirectly – as CO2 enters medulla, dissolves in CSF to form H+ - response is to
H+ (increasing H+ results in increasing depth and rate of respiration)
Peripheral chemoreceptors
Carotid – at junction of internal and external carotids - respond to rising
CO2, rising H+, and VERY LOW O2 – each causes increasing rate and depth of
respiration
Aortic – on the aortic arch – respond only to gases – rising CO2 and VERY
LOW O2 – results in increasing rate and depth of respiration
20) What other signals inform the brain of the need for increased respiration?
Proprioceptors provide information that joints are in motion
Stretch receptors in the muscles provide information that muscles are active.
Both indicate that metabolic needs are increasing (muscle is using more energy
and so inform the respiratory centre (the VRG) to increase breathing. Note that
this information initiates respiratory increases even before blood gases begin to
inform the chemoreceptors of that requirement.
21) By what nerves do the peripheral chemoreceptors communicate with the medulla, and
to which control centre do they transmit their information?
Carotid – via Cranial Nerve IX – Glossopharyngeal – to the VRG
Aortic – via Cranial Nerve X – Vagus – to the VRG
22) Via what nerves are the muscles controlled for inspiration? Name the muscles.
T1-T11 – the intercostal nerves innervate the external intercostals
C3-C5 – the phrenic nerve innervates the diaphragm
23) What is the Hering-Breuer reflex? What nerve carries the information to what
structure in the brainstem?
Stretch receptors in the smooth muscles of the lung (along the bronchi and
bronchioles) inform the pneumotaxic centre of the Pons via the Vagus nerve to
cut off inspiration during large inspirations. Prevents over-inflation of the lung.
Not active in adults during normal breathing but is thought to be active in
infants, at least initially, during normal breathing. Probably active in adults
during exercise, or with COPD (with air trapping), when normal tidal breathing
results in inflation of the lungs above normal levels of tidal breathing.
24) During normal breathing, indicate what phases of respiration are active or passive,
and how long (on average) each phase endures.
Inspiration – active – involves contraction of diaphragm and external
intercostals – lasts ~ 2 sec.
Expiration – passive – elastic recoil of the chest wall and the elastin around the
alveoli causes air to leave the lungs. – lasts ~3sec
25) What muscles are activated during active/forceful expiration?
internal intercostals
26) Explain what HAPE and HACE refer to and describe what is happening when they
occur.
At high altitude (HA) you have pulmonary edema (HAPE) or cerebral edema
(HACE) – extremes of high altitude sickness. Both result for the lower pressures
at high altitude that result in leakage of fluid into the lungs or around the brain,
respectively. HAPE results in severe respiratory limitations and can result in
Hemoptysis (coughing of blood). HACE can lead to reduced cognitive abilities,
coma or even death
27) What treatments exist for HAPE and HACE?
Dexamethazone is an anti-inflammatory intended to reduce the irritation in the
lungs the precedes HAPE
Diamox is a diuretic taken as a prophylactic (preventative) measure prior to
ascent. It causes loss of HCO3-, which stimulates breathing (metabolic acidosis)
28) Name 3 normal longer term adaptations when one acclimatizes to higher altitudes.
EPO (Erythropoietin) is released by the kidney and results in increased
production of RBCs
Lung capillary density increases
Muscle capillary density increases
New alveoli are produced in the lung
29) Explain what the “bends” are in relation to deep diving.
The greater pressure at depth induces more nitrogen to enter the tissues. This is
a relatively slow process, so occurs only over extended diving at depth. The
release of pressure as the diver ascends has to be slow enough to allow the
nitrogen to diffuse out of the tissues without forming bubbles – if bubbles form,
they may cause an embolism in arterioles or even arteries, resulting in ischemia
(lack of blood flow) to tissues. Permanent damage may result to sensitive (nonregenerative) tissues (brain or myocardium) and painful muscle cramps cause
the distorted, bent configuration of the body of a “bent” diver. treatment
usually involves repressurizing the diver in a hyperbaric chamber to force the
bubbles smaller and to re-enter the tissue, and the slowly decompressing to allow
time for the nitrogen to diffuse without bubble formation.
30)
31) Please draw and label, with appropriate volumes, a spirogram. In addition to the four
fundamental volumes, indicate two capacities that are the sum of 2 or more of the
volumes.
the 4 volumes are Residual Volume (RV - 1200ml) , Expiratory Reserve Volume
(ERV – 1200ml) Tidal Volume (TV – 500 ml), and Inspiratory Reserve Volume
(3100 ml) – Total lung capacity is the sum of all 4 (6000 ml). Vital capacity is the
volume of air that can be moved in and out of the lung with maximal effort (TV
+ ERV + IRV = 4800 ml
See the diagram in your notes or text for the proper labeling.
32) What is Bronchial Asthma? Describe the 4 factors that make bronchial asthma a
disease that limits air movement in the lungs.
An immune response in the lungs results in hypersensitive airways that result in:
mucus accumulation in the lumen
the epithelial layer swells with edema due to inflammation
the smooth muscle layer is grown larger and thicker (reducing lumen diameter
when contracting due to irritation (bronchoconstriction)
Increased size and number of goblet cells increases mucus production
Treatment modalities now include treatment of the underlying inflammatory
response, rather than just using bronchodilators that target the symptoms
33) What is COPD and what are the results?
A constellation of diseases that result in air-trapping with the lung,
hyperinflation and diminished flow through the airways. Smoking is the
number one contributor, but may also result from chronic bronchial asthma,
chronic bronchitis, or emphysema.
alveoli are damaged and non-functional in gas exchange.
reduced # of functional alveoli
increased # of dead air spaces that don’t communicate with the outside (never
exchange with fresh air)
reduced capillary network in lungs
long-term hyperinflation results in a barrel chest
34) Describe a pulmonary embolism, how it happens, what happens, and what the
consequences are. What is a saddle embolism?
A clot, usually from the leg veins but can also result from arm veins or even
from with the heart itself, travels up to and through the heart and travels into
the pulmonary circulation, eventually lodging where it is larger than the vessel
through which it is traveling (artery or arteriole) and resulting in a loss of blood
flow through that vessel. Results in loss of gas exchange in that area of the lung
(blood isn’t getting to those alveoli) and, if not treated, death of the pulmonary
tissue. If the vessel is large enough, it may result in death, but is most often not
fatal. Results in Dyspnea (shortness of breath), higher heart rate (tachycardia)
and pain which may be localized to the chest or may radiate down the arms or
up the neck. Treatment with “clot-busters” (anti-clotting medications) can be
successful. A saddle embolism is one in which the clot (embolus) blocks both
branches of an artery as it divides. If it is at the level of the pulmonary trunk as
it branches to left and right pulmonary arteries, it is a cause of sudden death.
35) Be aware of the health factors that smoking impacts, and the progression of
improvements if one quits (from page #17 in your notes)
36) Define or describe the following terms:
a) Hypoxia
low oxygen in the tissues
b) Hypoxemia low oxygen in the blood specifically
c) Hypercapnia high levels of carbon dioxide in the tissues
d) Dyspnea
difficulty breathing or shortness of breath
e) Apnea
absence or lack of breathing
f) Eupnea
normal breathing
g) Cyanosis
blue appearance of tissue (the lips esp.) due to hypoxemia
h) Laryngitis
inflammation of the larynx
i) Lysozymes enzymes found in the mucus secretions of the respiratory tract
that actually cause lysis of bacterial cells that are inspired and caught on the
mucus membranes
j) Defensins
enzymes that are also found in the same mucus secretions that
attack viral invaders of the respiratory system
k) glottis – opening to trachea between the vocal folds (chords)
l) Rima glottides opening between arytenoids cartilages in larynx – incompletely
covered by epiglottis during swallowing
m) Valsalva maneuver increasing abdominal pressure (as in birthing or
defecating) by tensing abdominal muscles and making expiratory efforst
while holding breath (glottis is voluntarily closed) – can also stabilize lower
spine during weight lifting – potentially dangerous due to increase in blood
pressure (over 300 mm Hg possible) – best to allow some breathing and only
partially close glottis
n) laryngitis
inflammation of the larynx – often involves loss of voice as
vocal chords are inflamed and therefore do not vibrate normally
o) influenza
an upper respiratory viral infection characterized by sudden
onset of a high fever, headache, body aches – does not involve GI effects (no
diarrhea or vomiting)
p) laryngoscope an endoscope designed to examine the larynx
q) surfactant
produced by type II (cuboidal) cells in the alveoli, this
phospholipid reduces surface tension of the moist endothelium of the alveoli
and prevents alveolar collapse
r) Hemoptysis coughing of blood