Anatomy of Respiration

Definition of Respiration

Def. The exchange of gas between an organism and its environment
Primary purpose: exchange of gas, secondary (imp to SLP) is energy source for speech.

Respiration Support Structure

*Respiration occurs within lungs, which are encased in a bony protective ribcage.
*Bony Thorax (area between head and abdomen)
*Vertebral column is bound by ribs, which are suspended from spinal column. Purpose to support & protect spinal cord, skull is to brain=>vertebrae is to spine

Atlas

*C1 is the atlas. It holds up the world (BRAIN)
*Has a reduced posterior prominence (nub=posterior tubercle)
*Superior articular facet is larger than C3-C7 because it articulates with the skull and gives skull a greater surface area to rest.
*Vertebral hole is larger bc its where the brain stem transitions to spinal cord.
*Dens of C2 protrudes though vertebral foramen of C1 (locks C1 into place)

Axis

*C2 "locks" into C1.
*Does have a small spinous process
*Identifying characteristic is the Dens (aka odontoid process)
*Dens is an additional layer of protection bc an insult or injury to C1 or C2 is life threatening.

Thoracic Vertebrae Landmarks

*T1-T12
*costal=rib process=protrusion (for ribs)
*Posterior attachment for ribs
*Transverse costal facet
*Superior/Inferior costal facet

Lumbar Vertebrae

*L1-L5
*Larger than cervical/thoracic for lifting/walking
*Attachment for back/abdominal muscles
Vertebrae are larger than Cervical or Thoracic bc they are engaged in more work.

Sacrum & Coccyx

*Fused bones known collectively as Sacrum & Coccyx.
*Ossified intervertebral disks (ossified=fused bone)

Kyphosis

Curvature of the T spine as a result of developmental problems/disease (osteoperosis, arthritis) Seen in geriatrics.

Things to Know About Ribs

*12 Pair
*Attached to thoracic vertabrae posteriorly
*Attached to sternum anteriorly by costal cartilage
*True ribs
*False ribs
*Floating ribs
*Rib cage is angled downward & many ribs attach to two vertebrae to allow elevation of the rib cage during inspiration.

Ribs: Their Basic Purpose

*Ribs protect the heart and lungs and provide a basis for respiration.
*The combination of bone and cartilage allows for protection and movement.

True Ribs

*Upper ribs #1-7
*Attach to the vertebral column posteriorly and to the sternum via costal cartilage anteriorly.

False Ribs

*Ribs #8-10 are attached to the vertebral column and sternum *But the costal cartilage has to move superiorly to attach to the sternum

Floating Ribs

#11 and #12 are only attached posteriorly

Parts of a Rib

*Head (where rib is attached to vertebrae)
*Tubercle (protrusion after the head)
*Angle (after the tubercle, the curved part of the rib)
*Shaft (after the angle, a wider part where the rib curves again)

Sternum parts

*Manubrium (top) attachment for the clavicle and 1st and 2nd ribs.
*Body
*Xiphoid process-bottom tip of sternum
*Sternal angle known as menubro- sternal angle, the angle between manubrium and sternum body

Pectoral Girdle

*The upper extremity attachment to Axis. (pec=chest) Consists of:
*Clavicle
*Scapula
-These bones support the arms/upper extremities

Clavicle

Clavicle-collar bone. provides anterior shoulder support

Scapula

*Scapula-chicken wings. *Posterior point of attachment for muscles that allow upper body movement.
*The scapula's only attachment is the clavicle, which attaches only at the sternum.
*Result is a vulnerable joint between clavicle and scapula.

Pelvic Girdle Purpose

Main purpose is to attach the legs to the vertebral column

Illium/Illiac

*Large wing-like bone similar to the scapula for the upper body. *Provides support for abdominal muscles
*Informally known as the hip-bone.
*The Illiac is the crest, or fan portion of the bone

Ischium/Pubis

paired lower structures of the pelvic girdle

Pubic Symphysis

Where the two pubic bones meet

Acetabulum

Near the hip joint, most common point to fracture, especially in older patients.

Rest vs Forced Expiration

*Rest expiration is a passive process and relies on gravity and the natural tendency of muscles to return to their resting state.
*Forced expiration is active and requires a different set of muscles.

What Forced Expiration Looks Like:

*Ribs expand side to side and front to back in 2 directions, so it must contract in 2 directions.
*Diaphragm must move up (abdominal muscles) and thorax must move down (thoracic muscles)

Thoracic Muscles

*Internal Intercostals
*Transverse Thoracis
*Serratus Posterior Inferior
*The muscles move only in 1 direction, so we need many sets to work antagonistically.

Internal Intercostals

Origin: Superior margin of each rib
Course: Up and medially
Insert: Inferior margin of above rib
Function: Depress rib cage
Notes:pg 110 Forced Expiration

Transversus Thoracis

Origin: Inner margin of sternum
Course: Laterally
Insert: Inner surface of ribs 2-6
Function: Depress rib cage
Notes: Forced Expiration

Serratus Posterior Inferior

Origin: Spinous process of T11-L3
Course: Up and laterally
Insert: Inferior margin of last 5 ribs
Function: Pulls ribs down & in
Notes: Muscle of Forced Expiration

Abdominal Muscles

-Abdominal Aponeurosis (name for a sheet-like tendon)-
*Rectus Abdominis
*Transverse abdominis
*Internal oblique
*External oblique
(Forced Expiration)

Abdominal Aponeurosis

*A sheet-like tendon that encases abdominal muscles
*Provides points of attachment for abdominal muscles
*Runs sternum to pubis

Abdominal Aponeurosis Linea Alba

(white line) from the xyphoid process to pubic symphsis. goes through belly button.

Abdominal Aponeurosis Linea Semiluminaris

lateral (side) to linea alba

Rectus Abdominus

Origin: Pubis
Course: Superiorly in segments, each separated by a strip of tendon
Insert: Xyphoid process and lower ribs
Function: Squeeze the abdomen
Notes: Forced Expiration. Your 6 pack. Of muscles. Not beer.

Transverse Abdominis (basic knowledge)

Courses laterally, deepest. Compress abdomen. (Forced Expiration)

Internal Oblique (basic knowledge)

Courses medially (middle muscle). Compress abdomen. (Forced Expiration)

External Oblique (basic knowledge)

Courses downward, most superficial. Compress abdomen. (Forced Expiration)

Posterior Abdominal Muscle

Quadratus Lumborum

Quadratus Lumborum

Origin: Iliac crest
Course: Up and in
Insert: Transverse process L1-5 & rib 12
Function:Support abdominal wall.
Notes: Forced Expiration. Don't think pull as much as support.

Upper Limb Muscles

Lattisimus Dorsi

Lattisimus Dorsi

Origin:Lower thoracic, lumbar, sacral vertebrae
Course: Fans out
Insert: humerous
Function: supports abdominal wall
Notes: Muscle of Forced Expiration (does contract, focus on support)

Diaphragm & Attachments

*Shaped like an inverted bowl/ dome
*Separates thoracic/ abdominal cavities
*Attached to ribs, xyphoid process, spinal column
*Unpaired, striated muscle

Anatomy of the Diaphragm

*Central tendon-translucent aponeurosis (tendon), floor for heart
*Three openings-(diaphragmatic hiatuses/openings) Esophageal hiatus (digestion), foramen vena cava (inferior vena cava passes through), aortic hiatus (decending abdominal aorta)
*Contracts down and forward (ribs move out and forward like venitian blinds) chest cavity expands.

Need for Accessory Muscles for Inspiration

*Not essential for rest breathing, but permits larger volumes of air to be inhaled for forced inspiration (regular breathing is diaphragmatic)
*Increased AP (anterior/ posterior dimensions)
*Attach to thorax, neck and back (remember muscles only shorten/contract to point of origin)

External Intercostal

Origin: Inferior surface of ribs 1-11
Course: Down and in
Insertion: Superior surface of rib above
Function: Elevate Rib cage & protect heart
Notes: Muscle for forced inspirtation, between each rib, pg 87.

Levator Cosarum Brevis

Origin: transverse process of C7-T11
Course: Down and out
Insertion: Tubercle of rib below
Function: Forced Inspiration. To elevate ribs "raise the roof" muscles.

Levator Costarum Longis

Origin: Transverse process of T7-T11
Course: down and out
Insert: 2nd rib below. skip a rib
Function: Elevate ribs
Notes: Forced Inspiration, Pg. 92

Serratus Posterior Superior

Origin: Spinous process of C7, T1-T3
Course: down & out
Insertion: beyond angle of ribs 2-5
Function: elevate ribs

Sternocleidomastoid

Origin: Mastoid process of temporal bone (behind ears on both sides)
Course: Down
Insertion: Clavicle and sternum
Function: Elevate the sternum, rotate head if contracted unilaterally.
Notes: Muscle of Inspiration. temporal is behind ears, both sides. 1 side contracts, head turns in that direction.

Scalenes (anterior, middle, posterior)

Origin: Transverse process of C3-C6, C2-C7, C5-C7.There is an overlap.
Course: down
Insertion: Rib 1 & 2
Function: Elevate ribs
Notes: Forced inspiration. Stabilize neck.

Pectoralis Major

Origin: Clavicle and most of sternum (2 heads)
Course: Fans into humerus
Insertion: Humerus
Function: Elevate sternum
Notes: Forced Inspiration. Fan shaped. Muscular bulk of chest.

Pectoralis Minor

Origin: Anterior surface of ribs 2-5
Course: Up and out
Insertion: Scapula
Function: Increase transverse dimensions of rib cage.
Notes: Forced inspiration. When contracted, it moves to the side

Serratus Anterior

Origin: Ribs 1-9. Deep to pectoralis major.
Course: Up, back
Insert: Scapula
Function: Elevates ribs
Notes: Forced inspiration. deep/ beneath pectoralis major. "saw tooth" muscles pull on scapula, which can't move in that direction so it raises ribs.

Levator Scapulae

Origin: Transverse process C1-C4
Course: Down
Insertion: Scapula
Function: Elevates scapula, neck support
Notes: Forced inspiration, primary neck support.

Rhomboideus Major & Minor

Origin: Spinous process T2-T5, C7 and T1.
Course: Down and laterally in
Insert: Scapula
Function: Stabilize pectoral girdle
Notes: Forced inspiration. Deep to trapezius. top=minor

Trapezius

Origin: Spinous process C2-T12
Course: fans laterally
Insertion: Scapula and clavicle
Function: Head/neck control, arm movement, shrug shoulders
Notes: Forced inspiration. Large back muscle

11 Forced Inspiration Muscles

I.External Intercostals
II.Levator Costarum
III.Serratus Posterior Superior
IV.Sternocleidomastoid
V.Scalenes
VI.Pectoralis Major
VII.Pectoralis Minor
VIII.Serratus Anterior
IX.Levator Scapulae
X.Rhomboideus major & minor XI.Trapezius
P,S,S,S,T,S,P,E,L,L,R

Respiratory Passages (Upper and Lower)

*Upper Tract-oral cavity, nasal cavity, pharynx
*Lower Tract-larynx, trachea, broncial tubes

Trachea

*Inferior to Larynx
*16-20 Cartilage horseshoe shaped rings
*Lined with ciliated (hair that beats)membrane
*Both rigid and flexible to accommodate changes in air pressure and allow mobility. Rigid for pressure for inspiration and expiration. Flexible to allow head and thorax to move, and increase in size when more air is needed.

Tracheal Ring

Trachea is C a shaped cartilage ring with cartilage anteriorly and muscle posteriorly.

Trachea into Bronci

*Trachea divides into mainstem bronchim, lobar bronchi, etc.
*Ends at terminal bronchi
*Right lung has 3 lobes/28 generations of bronchial tree
*Left lung has 2 lobes/14 generations of bronchial tree (allow room for heart, mediastinal structures)
*Terminal bronchioles serve alveoli

Why is There So Many Bronchi?

Many generations of bronchi to provide increased surface area for gas exchange.

Structures of Gas Exchange

*Alveoli at terminal (end) of bronchi (alveolus is singular) Alveolar walls are thin to facilitate gas exchange. 5 alveoli fit into 1mm. 1 alveoli surrounded by 2000 capillaries.
*300,000,000 alveoli in lungs vs 600 billion capillaries.
*Surrounded by capillary bed (vasculated) they are small and prolific, the most dense in body. 1 tsp of blood would cover a meter of surface squared.
*Exchange of O2 and Co2 across alveolar wall.

How the Airway is Kept Clean:

*Filtered by cilia
*C beats pollutants (up) superiorly to larynx
*Initiates cough/swallow
*Air warmed and humidified in passages. Cold air reduces ability of lungs to exchange gas. Humidified b/c alveoli need moisture to maximize mobility.

Emphysema

*Pollutants (environmental/tobacco related) kill cilia, thereby reducing cleansing (particles sit in alveoli, which causes changes)
*Pollutants settle in alveoli, which eventually undergo structural changes.
*Alveolar walls break down, former alveoli clusters join to form a single sac. (grapes to a single giant ball)
*Reduced surface for gas exchange
*Attempts at deeper breaths form barrel chest.

Asthma

An inflammation of the lungs. Does not affect alveoli. Brochioles are narrowed

COPD

Chronic Obstructed Pulmonary Disease. Chronic bronchitis and emphysema. Is progressive and irreversible. Does effect alveoli.

Prevent Emphysema and COPD

Don't smoke, avoid pollutants

Lung Lining is Made of:

*Lungs and surrounding structures are lined with pleural lining.
*Visceral pleurae line lungs (visceral pleurae is deep to the parietal pleurae)
*Parietal pleurae line all other structures (diaphragmatic, costal, mediastinal, apical)

Movement of Lungs

*Pleural linings form an airtight seal-encases. Lungs too small for thorax. This airtight seal keeps pleurae suspended. Space within viceral and pariatal pleurae is fluid filled. Moves as a unit.
*Lungs not attached to anything except heart/trachea
*Pleurae allow lungs to move with surrounding structures because of airtight seal.

Pleurisy

*Inflammation of pleurae
*Loss of lubricating fluid causes pain with respiration-pleurae is like saran wrap. no fluid creates adhesions. Fluid is like oil.
*Adhesions of parietal to visceral pleurae, they rub up against each other if they are inflamed.

Pneumothorax

*There's air in thoracic space around lung
*Compresses lung "collapsed lung"
*May need chest tube to drain air and allow lung to re-expand
*Causes: trauma, respiratory disease

Chest Tubes

Suck out air, gunk, and blood from thorax.

Boyle's Law

If volume of a container is increased, the pressure will decrease. If volume is decreased, pressure will increase.
*Basis for inspiration is this inverse relationship of pressure and volume*

Gas During Inspiration

*Gas moves from an area of higher pressure to an area of lower pressure.
*Pressure is the force exerted on walls of a container

Stages if Gas Exchange:Ventilation

Movement of air in conducting respiratory pathway. (mouth, nose, and trachea bring air down through passageways)

Stages if Gas Exchange: Distribution

Delivery of air to 300 million oxygen poor alveoli. (air is sent thorough bronchiole generations shared with alveoli)

Stages if Gas Exchange: Perfusion

Air migrates through capillary barriers that surround alveoli

Stages if Gas Exchange: Diffusion

Actual gas exchange across alveolar-capillary membrane

Respiratory Cycle

*Cycle is one inspiration, one expiration
*Normal adults complete 12-20 cycles per minute at rest. increase with work.

Inspiration & Expiration A.K.A.

Inhalation & Exhalation

Types of Vertebrae & Location

C1-C7 Cervical Vertebrae
T1-T12 Thoracic Vertebrae
L1-L5 Lumbar Vertebrae
Sacral Vertebrae
Coccygeal Vertebrae

Structure of a Vertebrae

(foramen=hole, process=protrusion)
*Spinous Process-posterior portion of vertabrae
*Corpous/body-solid part and anterior
*Transverse process-part that sticks out on the sides
*Vertebral foramen-hole for the spinal cord
*Intervertebral foramen-same as transverse foramen, holes that house spinal nerves
*Superior & Inferior articular facets/process-A means for adjacent vertebrae to articulate with one another, the mating surface for the vertebrae where they connect. Limit AP (anterior & posterior) movement. Allows rocking and rotary mvmt.
*Lamina-the neck, found on both sides.

Lordosis

Anterior curvature of the T spine. Many causes such as muscle weakness, being overweight, or pregnancy. Feel lower back weakness.

Scoliosis

Abnormal lateral curvature of the spine. Can be congenetal or acquired.

Spina Bifida

A birth defect where the neural tubes don't close completely. Can be cervical, thoracic or lumbar (generally lower). Spinal cord can be exposed due secondary to open vertebrae and the disability is related to the area of the spine affected.

How does Boyle's Law relate to gas exchange during inspiration?

*Given what we know, that gas moves from an area of high pressure to low pressure
*the diaphragm contracts down (sometimes using accessory muscles of inspiration)
*As it contracts down, the volume increases & the volume of the lungs and alveoli increase
*The pressure decreases, so air flows in from the outside (according to Boyles law) since air moves from high pressure to low pressure
*This is how we breath in.
*Remember* contract = expand
(at rest, diaphragm is down)

Respiration Cycles of various ages

newborn: 60
5 years: 20
15 years: 18
Adult: 12
*Reason why number is so high for babies? # of alveoli increases. 25 million at birth to > 300 million at 8 yrs old. # is retained through life. Also thorax grows as person grows. More surface area.

Tidal volume (TV)

*volume=amount
*Tidal is respiratory system at rest. (baseline)
*Volume of air exchanged during a respiratory cycle.
*Varies w/ age, body size, and level of physical exertion

Inspiratory Reserve Volume (IRV)

*Volume that can be inhaled above a passive tidal inspiration.
(inhale.hold breath.Inhale again)

Expiratory Reserve Volume (ERV)

*Volume that can be expired after passive tidal expiration
(exhale.hold breath.exhale again)

Residual volume

*Volume of air remaining in lungs after maximum exhalation
*When exercising, you use inspiratory and expiratory reserves.
*No matter how forceful you inh or exh. theres still some air left, or lungs will deflate.
*Exists bc lungs are stretched as a result of expanded thorax
*Heimlich uses residual volume

Dead Air

Volume of air within conducting passageways that cannot be involved in gas exchange (included in residual volume)
*it's the air in your mouth, nose, trachea not involved in gas exch. *Technically part of tidal volume, but not used

Lung Volumes/Capacity Graph

resting=base
capacity=deepest breath possible
slide shows wave graph. small waves (reg breathing) large waves (inspiratory and expiratory capacity) and always residual volume below.

Lung Capacity Terms

TLC-total lung capacity
IC-inspiratory capacity
FRC-functional residual capacity
VC-vital capacity

Volume Terms

IRV-Inspiratory reserve volume
TV-Tidal volume
ERV-Expiratory reserve volume
RV-Residual volume (includes dead air)

Vital Capacity

=IRV+TV+ERV (volume of air that can be inhaled following maximal exhalation) amt of air available for speech. 35%-60%=normal, 80% for loud
*keep talking and don't take a breath & keep going...use all reserves*

Functional Reserve/Residual Capacity (FRC)

=ERV+RV (volume of air remaining after passive exhalation) Left over is the reserve plus residual reserve. Normal breath out.

Inspiratory Capacity (IC)

=TV+IRV (maximum inspiratory volume possible after tidal expiration) after inspiring, the reserve you can use to still breath in.

Total Lung Capacity (TLC)

=IC+FRC (sum of IRV, TV, ERV, RV)

Respiratory Capacities Decrease When and Why?

@ age 25, product of age, size and gender.

Patm

Atmospheric pressure reference point. Baseline pressure outside body.

Pm

Intraoral/mouth pressure. Puff of air held in mouth.

Psg

Subglottic pressure (below vocal folds). Like cough. or swimming.

Ppl

Intrapleural pressure between visceral and parietal pleura, always negative-b/c lungs are in a continued state of expansion within the thoracic cavity. Cavity larger than lungs that fill it. If P always negative, air will always go to that area of low pressure.

Pal

Pressure in each alveoli (Boyles law)

Intrapleural Pressure

*Always negative b/c lungs are in a continued state of expansion. Body keeps pressure low so air always flows in.
*Lungs expanded b/c they do not occupy the whole thoracic cavity and are not attached pia musculature to perimeter.
*Without consistent pressure to maintain expansion, lungs would collapse. (saran wrap, once gets stuck, can't get unstuck) No muscles to maintain them being open-so they use pressure.

Relationship of pressures

1. Contraction of diaphragm
2. Lungs expand
3. Ppl becomes more negative
4. Pal degreases
5. Air flows into lungs
6. Reverses for expiration
*Fundamental idea-when volume increases, pressure decreases* Need to inspire.

Breathing pressure relationship graph gist:

*when diaphragm contracts & volume increases, there is a steady increase of air into lungs
*when diaphragm stops contracting, air stops flowing and volume decreases.
*when diaphragm contracts alveolar pressure decreases, because lung volume increases-gas flows to areas of neg. pressure, air is inspired.
*Pleural pressure always neg. bc lungs are always expanded.
*Plural pressure becomes more neg. during diaphragm contraction b/c contraction attempts to pull visceral pleura away from parietal plurae, increasing volume and space.Boyle's law says P will decrease and become more negative.

Expiration:

*Eliminates waste products of respiration (Co2)
*Rest expiration is passive (bc gravity and elasticity
*Forced expiration also possible by reducing thoracic cavity size (pull rib cage down & compress abdomen)
*like blowing up a balloon and letting it go*
*Restoring forces generate pressure themselves.

Relaxation Pressure

*The greater you distend or contort the material (chest wall), the greater the force is required to hold it in that position, and the greater the force with which it returns to rest. Aka. if you take a huge breath in, you must use forced expiration to return to rest position. Muscles always want to return to rest.

Speech & Breath

*Psg sub glottal pressure used to open vocal chords.
*Checking action (breath support) needed to restrain airflow during expiration for speech (since you only speak on expiration)
*Inspiration/expiration ratio 60/40% at rest, 10/90% during speech (short breath in and prolong breath to speak)
*Do not change volume inhaled. rely on checking action to maintain expiratory airflow.

Speech Function

Rest inspiration is active process
(for speech it is active process, but the cycle duration is altered)
Rest expiration is passive process
(active process for expiration in speech with checking action-makes cycle prolonged)