Chapter 2

Respiratory Structure and Function

What are the 12 ribs of the skeletal framework?

most connect to the sternum (breastbone) vis cartilage and lowest two “float”

What is the pectoral girdle of the skeletal framework?

Clavicles (collarbone) and Scapulae (shoulder blades)

What is the pelvic girdle of the skeletal framework?

Coxal (hip) bones and Vertebrae (sacral and coccygeal)

scapulae

shoulder blades

Vertebrae

– 7 cervical (neck)

– 12 thoracic (chest)

– 5 lumbar

– 5 sacral

– 5 coccygeal (tailbone)

Torso has upper and lower cavities partitioned off by what?

diaphragm

What is the upper cavity called and houses heart and lungs?

thorax

Whats the lower cavity called and contains much of digestive system and other organs and glands?

abdomen

The respiratory system is made up of the what two thigs?

pulmonary apparatus and the chest wall

Pulmonary apparatus

lungs and (lower) airways

Chest wall

rib cage wall, abdominal wall, diaphragm, and abdominal content

What is made up of C-shaped cartilages? (lower airways)

trachea (windpipe)

Where are the main stem bronchi? (lower airways)

to the right and left of the lungs

Where are the lobar bronchi? (lower airways)

to each lobe of the five lobes

How many divisions are their in lower airways?

20 generations

Where does gas exchange occur? (lower airways)

alveoli (300 million)

Lungs

porous and spongy

Where are the lungs five lobes located?

three on the right and two on the left

The lungs are covered by thin membrane called what?

visceral pleura

The lungs inner chest wall is covered by thin membrane called what?

parietal pleura

What connects lungs to chest wall?

pleural linkage

Rib cage wall forms what?

most of the thorax

Rib cage wall surrounds what?

the lungs (except at the bottom)

Rib cage wall consists of what?

thoracic vertebrae, ribs, costal cartilages, sternum, and pectoral girdle

The diaphragm forms what?

floor of the thorax

The diaphragm means what?

“fence between” (thorax and abdomen)

Abdominal wall consists of what?

15 vertebrae (lumbar, sacral, coccygeal), pelvic girdle, muscles, and connective tissue (abdominal aponeurosis and lumbodorsal fascia)

Abdominal content includes what?

stomach, intestines, etc.

Abdominal content is essentially what?

the density of water

Abdominal content is suspended from what?

undersurface of diaphragm by suction force

What happens when the abdominal wall and abdominal content are both together?

they can be thought of as an elastic bag filled with water

How are the pulmonary apparatus and chest wall are connected?

pleural linkage

When is the resting size of the pulmonary apparatus larger?

when linked than unlinked

When is the resting size of the chest wall smaller?

when linked than unlinked

Passive force

Natural recoil of muscles, cartilages, ligaments, and lung tissue

Surface tension of the alveoli

Pull of gravity

Active force

Rib cage wall muscles

Diaphragm muscle

Abdominal wall muscles

What are typically paired?

skeletal muscles

Origin of skeletal muscles

attachment to a more stable bone

Insertion of skeletal muscles

attachment to a more movable bone

Where is the more moveable bone brought toward?

the more stable bone

Where does Sternocleidomastoid originate?

in sternum and clavicle and inserts on skull behind ear

What does Sternocleidomastoid elevate?

ribs via sternum and clavicle

Where does Scalenus anterior originate from?

C3-C6 and inserts on inner border of top of first rib

What does Scalenus anterior elevate?

first rib

Where does Scalenus medius originate from?

C2-C7 and inserts on first rib

What does Scalenus medius elevate?

first rib

Where does Scalenus posterior originate from?

C5-C7 and inserts on the outer surface of the second rib

What does Scalenus posterior elevate?

second rib

Where does Pectoralis major originate from?

front surface of upper costal cartilages, sternum, and inner half of clavicle and insert into humerus

What does Pectoralis major elevate?

sternum and ribs

Where does Pectoralis minor originate from?

second through fifth ribs near their cartilages and inserts into the front surface of the scapula

What does Pectoralis minor elevate?

second through fifth ribs

Where does the Subclavius originate from?

undersurface of the clavicle and inserts on the first rib near its cartilage

What does Subclavius elevate?

first rib

Where does the Serratus anterior originate from?

the outer surfaces of the upper eight or nine ribs and inserts at the front of the scapula

What does Serratus anterior elevate?

upper ribs

How many connected muscles does External intercostals have?

eleven that fill the outer portions of the rib interspaces

The External intercostals form a sheet of muscle that originates from where?

the first rib, cervical vertebrae, and base of skull and links each rib to the adjacent rib

What does External intercostals elevate?

the ribs and stiffens their interspaces

How many connected muscles does Internal intercostals have?

eleven that fill the inner portions of the rib interspaces (except at the back of the rib cage)

The Internal intercostals primarily depress what?

ribs and stiffen their interspaces

What do Intercartilaginous Internal intercostals elevate?

the ribs

Where does Transversus thoracis originate from?

inner surface of the lower sternum and fourth or fifth costal cartilages and inserts into the second through sixth ribs

What does Transverus thoracis depress?

second through sixth ribs

Where does Latissimus dorsi originate from?

the thoracic (lower six), lumbar, and sacral vertebrae and back surfaces of lower three to four ribs and inserts into the humerus

The Latissimus dorsi contraction as a whole depresses what?

rib cage wall; however, individual fibers that insert into lower ribs can elevate them

Where does Serratus posterior inferior originate from?

2 lower thoracic and upper 2-3 lumbar vertebrae and inserts in lower border of lower four ribs

What does Serratus posterior inferior depress?

lower four ribs

Where does Serratus posterior superior originate from?

at C7 to T1-T3 or T4 with insertion on ribs 2-5 for elevation

Where does Lateral iliocostalis cervicis originate from?

surfaces of third through sixth ribs and inserts on fourth through sixth cervical vertebrae

What does Lateral iliocostalis cervicis elevate?

third through sixth ribs

Where does Lateral iliocostalis lumborum originate from?

the lumbodorsal fascia, lumbar vertebrae, and back surface of coxal bone and inserts in lower edges of lower six ribs

What does Lateral iliocostalis lumborum depress?

the lower six ribs

Where does Lateral iliocostalis thoracis originate from?

upper edges of lower six ribs and inserts on lower edges of upper six ribs

What stabilizes the Lateral iliocostalis thoracis?

the back of the rib cage wall and moves in concert with the cervicis and/or lumborum parts of the muscle group

Where does the twelve small muscles of Levatores costarum originate from?

C7 through T11 vertebrae and insert into the back surface of the rib below the vertebra of origin

What does Levatores costarum elevate?

the ribs

Where does Quadratus lumborum originate from?

top of the coxal bone and inserts in the first four lumbar vertebrae and lowest rib

What does Quadratus lumborum depress?

the lowest rib

Where does Subcostals originate from?

near the lower portion of the vertebral column on the inner surfaces of the ribs and insert in the inner surfaces of ribs above

What does Subcostals depress?

the ribs

Where does the diaphragm originate from?

the bottom of the sternum and lower six ribs and first three or four lumbar vertebrae and inserts into the central tendon

What are the two actions of the diaphragm?

Pulls downward on the central tendon to enlarge the thorax vertically and/or elevates the lower six ribs to enlarge the thorax circumferentially

Where does Rectus abdominis originate from?

front edge of coxal bone and inserts into the outer surfaces of the fifth through seventh costal cartilages and lower sternum

What does Rectus abdominis depress?

lower ribs and sternum

Where does External oblique originate from?

the upper surface of the coxal bone and abdominal aponeurosis near the midline and inserts on the lower eight ribs (outer surface and lower border)

What does External oblique depress?

lower ribs and forces front/sides of abdominal wall inward

Where does Internal oblique originate from?

the upper surface of the coxal bone and lumbodorsal fascia and inserts into the abdominal aponeurosis and lower borders of the costal cartilages of the lower three to four ribs

What does Internal oblique depress?

lower ribs and forces front and sides of abdominal wall inward

Where does Transversus abdominis originate from?

the upper surface of the coxal bone, lumbodorsal fascia, and inner surfaces of the costal cartilages of ribs seven through twelve and insert into the abdominal aponeurosis

What does Transversus abdominis force?

front and sides of abdominal wall inward

What are the pressures within the respiratory system?

Passive and active (muscular) forces

Alveolar pressure

inside the lungs (most important for speech production)

Pleural pressure

inside the thorax and outside the lungs (between the pleural membranes)

Abdominal pressure

within the abdominal cavity

Transdiaphragmatic pressure

difference between pleural and abdominal pressures

“Pump handle”

increases front-to-back diameter

“Bucket handle”

changes side-to-side diameter (These movements occur together and in phase)

How does the thorax become enlarged vertically?

pulls downward on the central tendon

How does the thorax become elevated?

by the lower six ribs to enlarge the thorax circumferentially