THE PARTS AND FUNCTIONS OF

RESPIRATORY SYTEM

* It is the system, consisting of tubes and is responsible for the exchange of gases in

Humans by filtering incoming air and transporting it into the microscopic

alveoli where gases are exchanged * Your respiratory system provides the energy

needed by cells of the body to funtion accroding to their designated tasks.

THE HUMAN RESPIRATORY SYSTEM

THE HUMAN RESPIRATORY SYSTEM

The organs of the “Respiratory Tract”

can be divided into two groups“STRUCTURALLY”

** The Upper Respiratory Tract ** The Lower Respiratory Tract

* Nose

* Nasal cavity

* Sinuses

* Pharynx

* Larynx

* Trachea

* Bronchial Tree

* Lungs

THE HUMAN RESPIRATORY SYSTEM

The organs of the “Respiratory Tract”

can be divided into two groups“FUNCTIONALLY”

** The Conducting Portion - system of interconnecting cavities and tubes that conduct air into the lungs

** The Respiratory Portion - system where the exchange of respiratory gases occurs

* Nose

* Pharynx

* Larynx

* Trachea

* Bronchi

* Respiratory bronchioles

* Alveolar Ducts

* Alveoli

The Respiratory Epithelium

THE HUMAN RESPIRATORY SYSTEMI. N O S E

A. N a s a l C a v i t y B. P a r a n a s a l S i n u s e s

II. P H A R Y N X

III. L A R Y N X A. E p I g i o t t i s B. V o c a l C o r d s

IV. T R A C H E A

v. B R O N C H I A. B r o n c h i a l T r e e

VI. L U N G S A. L o b e s o f t h e L u n g s B. P l e u r a l C a v i t i e s C. A l v e o l i

THE NOSE

* It provides an entrance for air in which air is

filtered by coarse hairs inside the nostrils.

* It has 2 portions : the external and internal

* The external portion is supported by a framework

of bone and cartilage covered with skin and lined with mucous membrane.

* The internal portion is a large cavity in the skull,

merging with the extrenal nose anteriorly and communicating with the throat posteriorly.

THE NOSE

The Nasal Cavity

* Interior area of the nose; lined with a sticky mucous membrane and contains tiny, surface hairs, cilia. divided medially by the nasal septum.

* Nasal conchae divide the cavity into passageways that are lined with mucous membrane, and help increase the surface area available to warm and filter incoming air.

•Particles trapped in the mucus are carried to the pharynx by ciliary action, swallowed, and carried to the stomach where gastric juice destroys any microorganisms in the mucus.

The Nasal Cavity

Paranasal Sinuses

* Sinuses are air-filled spaces within the maxillary, frontal, ethmoid, and sphenoid bones of the skull.

* These spaces open to the nasal cavity and are lined with mucus membrane that is continuous with that lining the nasal cavity.

* The sinuses reduce the weight of the skull and serve as a resonant chamber to affect the quality of the voice.

Paranasal Sinuses

THE PHARYNX

* The “throat” is a funnel shaped tube that lies posterior to the nasal cavity, oral cavity and larynx; and anteriorly to the cervical vertebra.

* It is composed of: Nasopharynx – uppermost portion Oropharynx – middle portion Laryngopharynx – lowermost portion

* It is a common passageway for air and  food and it provides a resonating chamber for speech sounds

THE PHARYNX

THE LARYNX

* It is an enlargement in the airway superior to the trachea and inferior to the pharynx.

* It helps keep particles from entering the trachea and also houses the vocal cords.

* It is composed of a framework of muscles and cartilage bound by elastic tissue

THE LARYNX

The Epiglottis

* It is a large leaf-shaped piece of cartilage.

* A flap of cartilage that prevents food from entering the trachea (or windpipe).

* During swallowing, there is elevation of the larynx

The Epiglottis

The Vocal Cords

* Inside the larynx, 2 pairs of folds of muscle and connective tissues covered with mucous membrane make up the vocal cords.

   a. The upper pair is the false vocal cords.

   b. The lower pair is the true vocal cords.

   c. Changing tension on the vocal cords controls pitch, while increasing the loudness depends upon increasing the force of air vibrating the vocal cords.

The Vocal Cords

* During normal breathing,

the vocal cords are relaxed and the glottis is a triangular slit. * During swallowing,

the false vocal cords and epiglottis close off the glottis.

The Vocal Cords

THE TRACHEA

* It is a tubular passageway for air, located anterior to the esophagus

* It extends from the larynx to the 5th thoracic vertebra where it divides into the right and left bronchi.

THE TRACHEA

THE TRACHEA

* The inner wall of the trachea is lined with ciliated mucous membrane with many goblet cells that serve to trap incoming particles.

* The tracheal wall is supported by 20 incomplete cartilaginous rings.

THE TRACHEA

BRONCHI

* The Bronchi are the two main air passages into the lungs.

* They are composed of the:

** “Right Primary Bronchus” - leading to the right lung.

** “Left Primary Bronchus” - leading to the left lung.

BRONCHI

The Bronchial Tree

* The bronchial tree consists of branched tubes leading from the trachea to the alveoli.

* The bronchial tree begins with the two primary bronchi, each leading to a lung.

* The branches of the bronchial tree from the trachea are right and left primary bronchi;     these further subdivide until bronchioles give rise to alveolar ducts which terminate in alveoli.

* It is through the thin epithelial cells of the alveoli that gas exchange between the blood and air occurs.

The Bronchial Tree

THE LUNGS

•The paired soft, spongy, cone-shaped lungs, separated medially by the mediastinum and are enclosed by the diaphragm and thoracic cage.

•2 layers of serous membrane, collectively known as pleural membrane, enclose and protect each lung.

** Parietal Pleura - outer layer attached to the thoracic cavity ** Visceral Pleura - inner layer covering the lung itself

THE LUNGS

Right-3 lobes Left-2 lobes

THE LUNGS

trachea

* The two organs that extract oxygen from inhaled air and expel carbon dioxide in exhaled air.

* This is the main and primary organ of the Respiratory System.

* The bronchus and large blood vessels enter each lung.

THE LUNGS

Lobes of the Lungs

* The right lung has three lobes. * The left lung has two lobes.

* Each lobe is composed of lobules

that contain air passages, alveoli, nerves,

blood vessels, lymphatic vessels,

and connective tissues.

Lobes of the Lungs

The Pleural Cavities

* A layer of serous membrane, between the visceral pleura and the parietal pleura.

* It contains a lubricating fluid secreted by the membranes that prevents friction between the membranes and allows their easy movement on one another during breathing.

The Pleural Cavities

The Alveoli

* They are cup-shaped out pouching lined by epithelium and supported by a thin elastic basement membrane.

•With that you can imagine having bunch of grapes with each grape indicating and alveolus.

* Alveolar sacs are 2 or more alveoli that share a common opening.

* This is where the primary exchange of gases occur.

The Alveoli

STRUCTURE FUNCTION

nose / nasal cavity  warms, moistens, & filters air as it is inhaled

pharynx (throat)  passageway for air, leads to trachea

larynx  the voice box, where vocal chords are located

trachea (windpipe)

 tube from pharynx to bronchi  rings of cartilage provide structure, keeps the windpipe "open"  trachea is lined with fine hairs called cilia which filter air before it reaches the lungs

bronchi  two branches at the end of the trachea, each lead to a lung

bronchioles  a network of smaller branches leading from the bronchi into the lung tissue & ultimately to air sacs

alveoli the functional respiratory units in the lung where gases (oxygen & carbon dioxide) are exchanged (enter & exit the blood stream)

Summary of FUNCTIONS

THE HUMAN RESPIRATORY TRACT

Pulmonary ventilation – moving air in and out of the lungs

External respiration – gas exchange between pulmonary blood and alveoli

Respiratory gas transport – transport of oxygen and carbon dioxide via the bloodstream

Internal respiration – gas exchange between blood and tissue cells in systemic capillaries

Events of RespirationEvents of Respiration

Completely mechanical process

Depends on volume changes in the thoracic cavity

Volume changes lead to pressure changes, which lead to the flow of gases to equalize pressure

Mechanics of Breathing (Pulmonary Mechanics of Breathing (Pulmonary Ventilation)Ventilation)

Two phases

Inspiration – flow of air into lung

Expiration – air leaving lung

Mechanics of Breathing (Pulmonary Mechanics of Breathing (Pulmonary Ventilation)Ventilation)

Diaphragm and intercostal muscles contract

The size of the thoracic cavity increases

External air is pulled into the lungs due to an increase in intrapulmonary volume

InspirationInspiration

InspirationInspiration

Largely a passive process which depends on natural lung elasticity

As muscles relax, air is pushed out of the lungs

Forced expiration can occur mostly by contracting internal intercostal muscles to depress the rib cage

ExhalationExhalation

ExhalationExhalation

Can be caused by reflexes or voluntary actions

Examples Cough and sneeze – clears lungs of debris Laughing Crying Yawn Hiccup

Nonrespiratory Air MovementsNonrespiratory Air Movements

Normal breathing moves about 500 ml of air with each breath (tidal volume [TV])

Many factors that affect respiratory capacity A person’s size Sex Age Physical condition

Residual volume of air – after exhalation, about 1200 ml of air remains in the lungs

Respiratory Volumes and CapacitiesRespiratory Volumes and Capacities

Residual volume

Air remaining in lung after expiration

About 1200 ml

Respiratory Volumes and CapacitiesRespiratory Volumes and Capacities

Vital capacity The total amount of exchangeable air

Vital capacity = TV + IRV + ERV

Dead space volume Air that remains in conducting zone and

never reaches alveoli

About 150 ml

Respiratory Volumes and CapacitiesRespiratory Volumes and Capacities

Functional volume

Air that actually reaches the respiratory zone

Usually about 350 ml

Respiratory capacities are measured with a spirometer

Respiratory Volumes and CapacitiesRespiratory Volumes and Capacities

Respiratory CapacitiesRespiratory Capacities

Sounds are monitored with a stethoscope

Bronchial sounds – produced by air rushing through trachea and bronchi

Vesicular breathing sounds – soft sounds of air filling alveoli

Respiratory SoundsRespiratory Sounds

Oxygen movement into the blood The alveoli always has more

oxygen than the blood

Oxygen moves by diffusion towards the area of lower concentration

Pulmonary capillary blood gains oxygen

External RespirationExternal Respiration

Carbon dioxide movement out of the blood Blood returning from tissues has higher

concentrations of carbon dioxide than air in the alveoli

Pulmonary capillary blood gives up carbon dioxide

Blood leaving the lungs is oxygen-rich and carbon dioxide-poor

External RespirationExternal Respiration

Oxygen transport in the blood

Inside red blood cells attached to hemoglobin (oxyhemoglobin [HbO2])

A small amount is carried dissolved in the plasma

Gas Transport in the BloodGas Transport in the Blood

Carbon dioxide transport in the blood

Most is transported in the plasma as bicarbonate ion (HCO3

–)

A small amount is carried inside red blood cells on hemoglobin, but at different binding sites than those of oxygen

Gas Transport in the BloodGas Transport in the Blood

Exchange of gases between blood and body cells

An opposite reaction to what occurs in the lungs

Carbon dioxide diffuses out of tissue to blood

Oxygen diffuses from blood into tissue

Internal RespirationInternal Respiration

Internal RespirationInternal Respiration

A Summary of A Summary of External External Respiration, Gas Respiration, Gas Transport, and Transport, and Internal Internal RespirationRespiration

Activity of respiratory muscles is transmitted to the brain by the phrenic and intercostal nerves

Neural centers that control rate and depth are located in the medulla

The pons appears to smooth out respiratory rate

Normal respiratory rate (eupnea) is 12–15 respirations per minute

Hypernia is increased respiratory rate often due to extra oxygen needs

Neural Regulation of RespirationNeural Regulation of Respiration

Neural Neural Regulation Regulation of of RespirationRespiration

Physical factors Increased body temperature Exercise Talking Coughing

Volition (conscious control) Emotional factors

Factors Influencing Respiratory Rate Factors Influencing Respiratory Rate and Depthand Depth

Chemical factors

Carbon dioxide levels

Level of carbon dioxide in the blood is the main regulatory chemical for respiration

Increased carbon dioxide increases respiration

Changes in carbon dioxide act directly on the medulla oblongata

Factors Influencing Respiratory Rate Factors Influencing Respiratory Rate and Depthand Depth

Chemical factors (continued)

Oxygen levels

Changes in oxygen concentration in the blood are detected by chemoreceptors in the aorta and carotid artery

Information is sent to the medulla oblongata

Factors Influencing Respiratory Rate Factors Influencing Respiratory Rate and Depthand Depth

Respiratory DiseasesRespiratory Diseases

Exemplified by chronic bronchitis and emphysema

Major causes of death and disability in the United States

Chronic Obstructive Pulmonary Chronic Obstructive Pulmonary Disease (COPD)Disease (COPD)