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Lecture #1: Anatomy of the Lower Airway and
Physiology of Breathing
Learning Objectives
• Know the terminology used to describe an anatomical position/plane
• Know the anatomical terminology of the lower airway structures and diafragma (know
bold-printed structures)
• Describe the muscles that play a role in inspiration and expiration
• Describe how inspiration and expiration are regulated
Anatomical Terminology
Terms used to describe anatomical positions/locations:
1. Medial vs. Lateral
• Medial → toward the midline of the body
• Lateral → away from the midline
2. Proximal vs. Distal (extremity)
• Proximal → closer to the center (trunk of the body, i.e.
heart) or the limb’s point of attachment to the trunk
• Distal → farther away from the center (trunk of the
body, i.e. heart) or the limb’s point of attachment to the
trunk
3. Superior vs. Inferior
• Superior → toward the head end of the body; above
• Inferior → away from the head; below
4. Posterior vs. Anterior
• Anterior → toward the front
• Posterior → toward the back/rear
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Anatomical Planes
1. Frontal (coronal) plane:
Vertical plane that divides the body into
anterior and posterior parts (front and back)
2. Sagittal plane:
Plane perpendicular to the ground which divides
the body into right and left parts
➔ May be along the midline of the body and
split it into two halves (mid-sagittal) or
away from the midline and split it into
unequal parts (para-sagittal)
3. Transverse (horizontal) plane:
Horizontal plane that divides the body into superior and inferior parts
Terminology
Anatomical terminology in Latin:
• Left → sinister
• Right → dexter
o Mnemonic: LSD R (left sinister, right dexter)
• Lung → pulmo
• Right lung → pulmo dexter
• Left lung → pulmo sinister
General Anatomy
Thorax
o The area between the clavicles and the diaphragm (= which
separates the thorax from the abdomen)
o Includes structures such as the lungs, small blood vessels, major
blood vessels from the heart, the trachea, etc.
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Location of the Lungs
• Shows size of lungs during inhalation vs. exhalation
o During inhalation, the lungs can expand up to the lower part of the thoracic
vertebrae, more specifically the 9th rib
Rib Cage
• The arrangement of ribs attached to the vertebral column and sternum in the thorax, that
encloses and protects the heart and lungs
• Consists of:
a) 12 pairs of costae (ribs) each terminating anteriorly in a costal cartilage
o All ribs articulate with the vertebral
column
b) Sternum (separated into 3 parts)
Types of ribs:
1. Ribs 1-7
• Only the costal cartilages of the upper
seven ribs, known as true ribs,
articulate directly with the sternum
The remaining five pairs of ribs are false ribs:
2. Ribs 8-12
• The costal cartilages of ribs 8-10
articulate anteriorly with the costal
cartilages of the ribs above
o = Connect to the sternum
indirectly via the costal
cartilages of the ribs above them
Lecture #1: Anatomy of the Lower Airway and
Physiology of Breathing
Learning Objectives
• Know the terminology used to describe an anatomical position/plane
• Know the anatomical terminology of the lower airway structures and diafragma (know
bold-printed structures)
• Describe the muscles that play a role in inspiration and expiration
• Describe how inspiration and expiration are regulated
Anatomical Terminology
Terms used to describe anatomical positions/locations:
1. Medial vs. Lateral
• Medial → toward the midline of the body
• Lateral → away from the midline
2. Proximal vs. Distal (extremity)
• Proximal → closer to the center (trunk of the body, i.e.
heart) or the limb’s point of attachment to the trunk
• Distal → farther away from the center (trunk of the
body, i.e. heart) or the limb’s point of attachment to the
trunk
3. Superior vs. Inferior
• Superior → toward the head end of the body; above
• Inferior → away from the head; below
4. Posterior vs. Anterior
• Anterior → toward the front
• Posterior → toward the back/rear
, 2
Anatomical Planes
1. Frontal (coronal) plane:
Vertical plane that divides the body into
anterior and posterior parts (front and back)
2. Sagittal plane:
Plane perpendicular to the ground which divides
the body into right and left parts
➔ May be along the midline of the body and
split it into two halves (mid-sagittal) or
away from the midline and split it into
unequal parts (para-sagittal)
3. Transverse (horizontal) plane:
Horizontal plane that divides the body into superior and inferior parts
Terminology
Anatomical terminology in Latin:
• Left → sinister
• Right → dexter
o Mnemonic: LSD R (left sinister, right dexter)
• Lung → pulmo
• Right lung → pulmo dexter
• Left lung → pulmo sinister
General Anatomy
Thorax
o The area between the clavicles and the diaphragm (= which
separates the thorax from the abdomen)
o Includes structures such as the lungs, small blood vessels, major
blood vessels from the heart, the trachea, etc.
, 3
Location of the Lungs
• Shows size of lungs during inhalation vs. exhalation
o During inhalation, the lungs can expand up to the lower part of the thoracic
vertebrae, more specifically the 9th rib
Rib Cage
• The arrangement of ribs attached to the vertebral column and sternum in the thorax, that
encloses and protects the heart and lungs
• Consists of:
a) 12 pairs of costae (ribs) each terminating anteriorly in a costal cartilage
o All ribs articulate with the vertebral
column
b) Sternum (separated into 3 parts)
Types of ribs:
1. Ribs 1-7
• Only the costal cartilages of the upper
seven ribs, known as true ribs,
articulate directly with the sternum
The remaining five pairs of ribs are false ribs:
2. Ribs 8-12
• The costal cartilages of ribs 8-10
articulate anteriorly with the costal
cartilages of the ribs above
o = Connect to the sternum
indirectly via the costal
cartilages of the ribs above them
