Correct Answers Included | A+ Score
What do we call the pressure inside vs outside the lungs? - Pressure within the lungs:
alveolar pressure
Pressure outside the lungs: atmospheric pressure
Describe how differences in alveolar pressure and atmospheric pressure enable breathing -
Through contraction of inspiratory muscles, we expand the chest cavity. As the lungs
expand, alveolar pressure gets lower than atmospheric pressure. This draws air into the lungs,
to equalize pressure. At that point, muscles contract to reduce the volume of the chest cavity.
This creates positive pressure within the lungs, pushing air out.
How many times per minute does the inhalation-exhalation cycle occur in adults? - 12-18
What is the ratio of expiration to inhalation during normal tidal breathing? - 60%-40%
What is the ratio of expiration to inhalation during breathing for speech? - 90%-10%
What % total capacity do the lungs have at rest? - 40%
Describe the right lung vs left lung - Right: shorter, broader, bigger. Liver underneath
forces it up a bit. Three lobes.
Left: Smaller, heart takes up space. Two lobes.
Describe the relationship between bronchi, bronchioles, and alveolar ducts - In the lungs,
bronchi subdivide into bronchioles. Bronchioles repeatedly subdivide until they become very
thin. They communicate with alveolar ducts that open into tiny air sacs in the lungs
What is the trachea? - A tube about 11 centimeters long formed by approximately 20
rings of cartilage. The rings are incomplete at the back, where the trachea comes into direct
contact with the esophagus. The last tracheal ring splits into the left and right primary bronchi
at T5
Describe the makeup of the spinal column - 32-33 individual vertebrae.
7 cervical vertebrae
12 thoracic vertebrae
5 lumbar vertebrae
,5 sacral vertebrae (fused in adults)
3-4 coccygeal vertebrae (fused, called the coccyx)
What are the three parts of the sternum? - Manubrium, body, xiphoid process
What is the manubrium? - The uppermost part of the sternum. Provides the attachment
for the clavicle and first rib
What is the body/corpus? - Long and narrow middle of the sternum. Rib cartilages 2-7
attach to the body.
What is the xiphoid process? - Projection of cartilage at the bottom of the sternum
Describe the composition of the ribcage - The sternum is the anterior surface
12 thoracic vertebrae in the posterior surface
12 pairs of ribs that connect laterally from the vertebrae to their individual costal cartilages
How does the diaphragm move? - Muscle fibers insert into the central tendon of the
diaphragm and contract to pull the central tendon down and forward to expand the thoracic
cavity
What are the intercostal muscles? - 11 paired internal intercostals and 11 paired external
intercostals
What do the internal intercostals do? - pull the ribs downward to decrease the diameter
of the thoracic cavity for exhalation
What do the external intercostals do? - raise the ribs up and out to increase the diameter
of the thoracic cavity for inhalation. Because they expand the thoracic cavity, the external
intercostals provide a large amount of the total respiratory capacity, so they're crucial for
speech breathing. They also perform a checking action, along w other inspiratory muscles, to
control the flow of air leaving the lungs during speech
What is the function of the diaphragm? - distends abdomen, enlarges vertical dimension
of thorax, depresses central tendon of diaphragm
What is the function of the serratus posterior superior? - Elevates rib cage
What is the function of the levator costarum brevis? - Elevates rib cage
What is the function of the levator costarum longis? - Elevates rib cage
, What are the three key neck muscles involved in respiration? - Sternocleidomastoid,
trapezius, scalenes
What does the sternocleidomastoid do? - elevates sternum, and thus, indirectly, the
ribcage
What does the trapezius do? - Controls and elongates neck and indirectly influences
respiration
What do the scalenes do? - (anterior, middle, posterior) stabilize and rotate the head.
These muscles are attached to the first two ribs, and therefore indirectly enlarge the vertical
dimension of the thorax
What does the pectoralis major do? - Increases transverse dimension of rib cage through
elevation of sternum
What does the pectoralis minor do? - Increases transverse dimension of ribcage
What does the serratus anterior do? - elevate ribs 1-9
What does the levator scapulae do? - elevates scapula, supports neck
What does the rhomboideus major do? - Stabilizes shoulder girdle
What does the rhomboideus minor do? - Stabilizes shoulder girdle
What does the transversus thoracis do? - Depresses ribs 2-6
What does the subcostal muscle do? - depresses thorax
What do the serratus posterior inferior muscles do? - Pull the ribcage down and thus aid
in exhalation
What does the lattismus dorsi do? - Stabilizes posterior abdominal wall for expiration
What does the rectus abdominis do? - flexes vertebral column
What does the transversus abdominis do? - compresses abdomen
What does the internal oblique abdominis do? - Compresses abdomen, flexes and rotates
trunk
What does the quadratus lumborum do? - supports abdominal compression through
bilateral contraction, which fixes the abdominal walls