RESPIRATORY SYSTEM

STRUCTURES OF THE RESPIRATORY SYSTEM

Nose, nasal cavity, pharynx (throat), larynx (voice box), trachea (windpipe), bronchi,

lungs.

Upper respiratory tract: nose and pharynx and associated structures

Lower respiratory tract: larynx, trachea, bronchi, and lungs.

FUNCTIONS OF THE RESPIRATORY SYSTEM

Two portions:

Structures that consists of interconnecting cavities and tubes (Conduction portion)

Structures that allow for the exchange of gases (Respiratory function)

Gets rid of wastes esp. CO2

Nose - filters choncha, hairs and mucus Trap dust and din

Nasal cavity - lined with mucous, blood vessels heat and warm air, adjusts air to body

temperature. Mucous traps dust on mucous membrane and cilia trapped particles toward

pharynx is swallowed. Destroyed by enzymes and HCL in the stomach.

Is divided by perpendicular plate& nasal septum. Nasal turbulence: functions Slow air,

filter air and Temp, and moisture levels.

From cranial cavity by cribiform plate of ethmoid bone anterior from mouth by hard

palate.

3 nasal concha: Superior and medial are part of the ethmoid bone

Inferior Nasal Concha is a skull bone.

Cribiform plate holds olfactory receptors, sense of smell.

Air moves through nasopharynx.

Sinuses - help decrease weight in skull, and body. Empty spaces in bone. Resonance of voice.(chamber) Constantly secrete mucous. Sinusitis when stopped up. Usually dry and inflamed nose. Rhinoitis is a runny nose.

Pharynx - Located behind oral cavity, three zones of tonsils

1) nasopharyngeal on nasal cavity, area where beginning of air passage ways to the
lungs 1st cilia on top soft palate, palantine tonsil; lymphatic tissue; filter; can block
eustachian tube; infection results

2) oropharyngeal C3, Posterior to adenoids or pharyngeal tonsil: filters

3) laryngopharyngeal: voice box areas; sub-linguinal or laryngotonsils
Within pharynx have 3 pairs of tonsils: 1) pharyngeal or adenoids 2) palantine 3)
linguinal. Upper pan of air passage way from nose to voice box.

Larynx - Enlargement in airway between pharynx and trachea. Joins pharynx to trachea which is your windpipe. Houses vocal cords. Air vibrates. Trachea; windpipe. Joins lungs to above.

Trachea - split to primary bronchi. Lungs to alveoli - exchange of gases.

Upper respiratory -generally holds bacterial - head cold can lead to worse Lower viral - chest - hard to get rid of

Nose - cartilage in front called external nares (hairs) opening of air passage

To 2 small open called external nares - slows air currents.

Into nasal cavity lined w/ mucous

Associated with nasal cavity is nasal septum. Have two nasal bones - nasal concha -

spiral; shell have 3:1) superior 2) inferior 3) medial

Slow air currents and filters air/ adjusts moisture and temp levels as goes to lungs to

body's temperature

Soft & hard palates of hard plate and ethmoid bone nasal cavity Out of cavity from oropharynx to laryngopharynx.

Nasal cavities have 4 major pairs – maxillary, frontal, 2 lacrimal sinuses - ethmoid

sinuses (behind lacrimals)

The maxillary, nasal, frontal, ethmoid and sphenoid bones form the nasal cavity

Nasal septum - thin blade divides cavity into left and right-condition; deviated septum

Cartilages that make up larynx

3 single

Larynx - enlg Voice box. Pieces of cartilage - 3 paired and 3 single: Thyroid cart - single

in neck adam's apple (Men have protrusion) Lgst in body.

Epiglottic cartilage (posterior) - Gag reflex if stimulated - swallowing moves up and back to keep from dropping into esophagus. Bag patient tube/ for opening airway.

Circoid cartilage - single - under thyroid - trachiostomy

3 paired

Arytenoid — pressure on vocal cords alters pitch of voice. Articulates with the superior

border of the enlarged portion of the cricoid cartilage. Holds muscle and regulates tension

for vocal cords.

Corniculate; opening and closing of glottis; paired w/ arytenoid

Cuneiform; lies within folds of tissue that extend between lateral aspect of each arytenoid

cartilage and the epiglottis. Stiffens soft tissue within region

Inside larynx there are two pairs of horizontal folds of mucous membrane. Upper fold is false vocal cord. Lower - true vocal cord.

Lower fold (True) contains elastic fibers responsible for vocal sounds. Forces air between cords. Increases tension for high pitch, decreases tension for low pitch.

Trachea - wind pipe - tube structure - connects upper resp. to lower resp. tract - made

up of cartilage 20 c-shaped rings of cartilage called tracheal cartilages.- adds structural

support and protection. C-shape does not close which allows for distortion upon

swallowing.

When bolus is being swallowed- trachea will expand and contract. Not peristalsis -

epiglottis has peristalsis.

Travels T-l toT-5

Splits - bifurcates - 2 gigantic tubes - primary bronchi R & L to ea. Lung

Goes to carina where a lot of cancer will form — air comes down — slows - turbulence —

slows and trapped irritants can create bronchial ca. Lung could collapse.

Brachial tree - roots and trunk appearance.

Splits - called the carina

Prim bronchi branch - 2ndary - tertiary - terminal bronchi - alveolus (air sacs)

Air sacs - clusters of bubbles for gas exchange - a lot of diffusion (not osmosis)

Alveolar ducts end at alveolar sacs

An extensive network of capillaries — they are surrounded by a network of elastic fibers.

Recoil of these fibers during exhalation reduces the size of the alveoli and helps push air

out of the lungs

Cystic fibrosis - lung tissue is fibrotic - can't exchange gasses

Lungs - 2 lungs -right & left; located within thoracic cavity

Left 2 lobes - 1 fissure

Right 3 lobes - 2 fissures

Fissures separate lobes of lung

Cardiac notch where heart sits

Encl in thoracic cavity -

Sitting in pleural membrane

Membrane is a “serous membrane" - outer and inner layer

Gutter- parietal outside pleural cavity

Inner - visceral ties light on top of lungs

Serous fluid - within pleural cavity — separates the two layers — lubrication

Right lobes: superior, middle, inferior

Left lobes: superior and inferior

Breathing mechanisms:

Respiration -the exchange of gasses between the atmosphere, blood, and cells. Three steps:

1) Pulmonary ventilation, (lung) or breathing- is the inspiration (inflow) and the expiration (outflow) of air between the lungs and the atmosphere. Inspiration is the force of inflow of air to move the lungs.

2) External (pulmonary) respiration. The exchange of gases between the air spaces
of the lungs and blood in the pulmonary capillaries. The blood gains O2 and
loses CO2.

3) Internal (tissue respiration). The exchange of gases between blood in systemic
capillaries and tissue cells. The blood loses O2 and gains CO2. Within the cells,
the metabolic reaction that takes in O2 and give off CO2 is called cellular
respiration.

Control Centers Of Breathing

Controlled by the Pons and Medulla called the respiratory center - brain stem

Antagonistic:

Pnuemotaxic area in the medulla limits inspiration and inhibits expiration.

Apneustic area - the lower portion of the pons functions when pnuemotaxic area isn't

working. Prolongs inspiration and inhibits expiration.

Damage to Cl to C3 interferes with respiratory area (Brain Stem)

Change respiratory rates:

1. Stretch receptors located in the bronchi and the lining of the lungs - keeps
lungs from over inflating.

2. Chemical changes - normal if chemicals (gases) are even - if acidic if
hydrogen levels are too high if blood pressure is UP respiration is DOWN.
If blood pressure is DOWN respiration is UP. Greater Blood Pressure rate
down to equalize reduced blood pressure makes harder to get air out

3. Changes in body temperature. Hot makes faster expulsion of air - Cold makes
less O2/ cc of air - slow respiration.

4. Severe or sudden pain. I.e. Giving birth: increases rate

5. Stretching sphincters - feel like gasping for air

6. Sudden irritation or pain due to sneezing, coughing etc. Laryngeal spasm.

Five Functions of Respiratory System

1. Provide area for gas exchange between air and circulating blood.

2. Move air to and from the exchange surfaces of the lungs.

3. Protecting respiratory surfaces from dehydration, temperature changes, or
other environmental variables and defending the respiratory system from
invasion of pathogens.

4. Producing sounds.

5. Providing olfactory sensations to the CNS from the olfactory epithelium in
the superior nasal cavity. (Smell)

Exercise and Breathing

Rate increases with O2 usage by skeletal muscle movement and an amount of C02 is produced. Proprioceptors transmit stimuli to respiratory center during muscle contraction. Which stimulate other receptors when joint reflex is triggered. Feeling out of breath is the inability of the circulatory system to move blood between the lungs and body cells rather than respiratory system to move in sufficient amounts of air.