The Respiratory SystemBy: Valentina Echeverry, Nicole Delgado, David Raza, Alexandra Ocasio

Functions of the Respiratory System:1. Performs gas exchange-- converts oxygen carbon dioxide2. Inspiration and expiration -- breathing in and breathing out air is conducted toward or away from the lungs.3. Respiratory system works with the cardiovascular system to accomplish 4 respiratory systems-- pulmonary ventilation-- external respiration-- internal respiration --transport of gases

Four Events:Pulmonary Ventilation The entrance and exit of air into and out of the lungs.External respiration the exchange of gases between air and blood.Internal respiration the exchange of gases between blood and tissue fluid.Transport of Gases to and from the lungs and the tissues.

The Respiratory tract:• Nasal cavity • Nostril• Pharynx• Epiglottis• Glottis• Larynx• Trachea• Right & Left bronchus• Bronchiole• Lung• Diaphragm• Pulmonary Venue• Pulmonary Arteriole• Alveolus• Capillary Network

Upper Respiratory Tract:• Nasal cavities• Pharynx• Glottis• Larynx-- Nasal Cavities: Hollow spaces in nose; filter, warm and moisten air-- Pharynx: Lies between nasal cavity and larynx; connection to surrounding regions-- Glottis: Opening into larynx; passage of air into larynx-- Larynx: Voice box; sound production

Lower Respiratory System:• Trachea• Bronchi• Lungs• Alveoli• Pulmonary Capillaries-- Trachea: Tube that connects larynx with bronchi; passage of air to bronchi-- Bronchi: Paired tubes that enter the lungs; passage of air to lungs-- Lungs: Organs that occupy lateral portions of thoracic cavity; gas exchange-- Alveoli: Air sacs that branch from bronchioles; passage of into and out of pulmonary capillaries-- Pulmonary Capillaries: Capillaries that cover surface of alveoli; receive oxygen, deliver CO2 from tissues to alveoli

The Nose• A prominent feature of the face • Only external part of respiratory system.• Air enters the body though external openings

called nostrils.• The nose contains two nasal cavities, separated

from one another by a septum. • The nasal cavities are lined with mucus

membranes.• The nasal cavities also communicate with

paranasal sinuses. They are air filled spaces that reduce the size and the weight of the skull

The Pharynx• Funnel- shaped passageway that connects the nasal and oral cavities to

the larynx.• The pharynx is referred to as the throat.• Has three parts- The nasopharynx where nasal cavities open posteriorto the soft palate.- The oropharynx where the oral cavity joins the pharynx- The laryngopharynx opens into the pharynx• The soft palate has a soft extension called the uvula.• The single pharyngeal tonsil (adenoid) helps defend against infection.• In the pharynx, the air passage and the food passage cross because the

larynx, which receives air, is anterior to the esophagus which receives food.

- Larynx and trachea are normally opened allowing air in while the esophagus is normally collapsed and opens only when the person swallows.

The Larynx- A cartilaginous structure that serves as a

passageway for air between the pharynx and trachea.

- The vocal cords are mucosal folds supported by elastic ligaments, and the slit between the vocal cords is an opening called the glottis.

- When food is swallowed, the larynx moves upward against the epiglottis, a flap of elastic cartilage that prevents food from passing through the glottis into the larynx.

The Trachea• Commonly known as the windpipe.• Tube connecting the larynx to the primary bronchi.• Trachea lies ventral to the esophagus and is held open by C-

shaped cartilaginous rings.• The C-shaped rings allows the esophagus to expand when

swallowing.• The mucosa that lines the trachea has a layer of cilia that

project from the epithelium keep the lungs clean by sweeping mucus toward the pharynx.

Fun Fact:Smoking is known to destroy this cilia, and the soot collects in the lungs.• Tracheostomy may be done if the trachea is blocked by making

an incision in the trachea.

The Bronchial Tree• The trachea is divided into the left and right

bronchi. Which leads into the left and right lungs. • Bronchioles-smallest conducting airways Fun FactDuring an Asthma attack, the smooth muscle of the bronchioles contracts causing constriction and wheezing.

The Lungs• Paired cone-shaped organs• Both are separated by the mediastinum• The apex is the superior, narrow portion of the lung.• The base is the inferior broad portion that curves to fit the dome-shaped

diaphragm.• Each lobe of the lung is further divided into lobules, each lobule has a

bronchiole supplying many alveoli.• Pulmonary capillaries surround and cover each alveolus of the lung. • Elastic connective tissue binds the air passages to the blood vessels

within each lung.- Which helps the lungs return to their resting position, or recoil when a

person exhales. • The pleurae is a serious membrane in which each lung is enclosed within.• Serous fluid creates surface tension: the tendency for water molecules to

cling to each other and to form a droplet. It also holds the two pleural layers together which holds the lungs open against the chest wall.

The Alveoli• With each inhalation, air passes by way of the

bronchial tree to the alveoli.• Each aveolus is covered with an extremely thin

layer of water-based tissue fluid.• Infant respiratory distress syndrome- now

treatable surfactant replacement therapy.

Pause:• ACTIVITY :D

Respiratory Membrane• Consists of the juxtaposed alveolar epithelium and

the capillary endothelium.• Very little tissue fluid separates the two portions

of the respiratory membrane.• A person with emphysema has a reduced amount

of respiratory membrane.

Ventilation• Ventilation: the manner in which air enters and

exits the lungsInspiration:- Active phase of ventilation- Phase in which the diaphragm and the external

intercostal muscles contract- The ribcage moves up and outward during the

process of inspiration.- Flow of air into the alveoli is passive

Ventilation continuedExpiration:- Passive phase of ventilation– no muscular effort is

required- Diaphragm resumes its dome shape and the rib

cage moves down and in.

Respiratory Volumes• When we are relaxed the amount of air is called

the tidal volume.• The maximum volume of air during a single

breath is called the vital capacity.• Forced inspiration is called the inspiratory reserve

volume.• In an adult 70% of the tidal volume reaches the

alveoli but 30% remains in the airways. This is called dead space air.

Control of Ventilation• The basic rhythm of ventilation is controlled by a

primary respiratory center located in the medulla oblongata.

• Nervous input- Observation of ones own breathing patterns influences the brain.

• Chemical input- The respiratory center is sensitive to the levels of carbon dioxide, and hydrogen ions. When they rise rate and depth of breathing increases.

Upper Respiratory Tract Infections• Sinusitis- infection of the cranial sinuses, the

cavities within the facial skeleton that drain into the nasal cavities.

• Otitis Media- bacterial infection of the middle ear.• Tonsillitis- When the tonsils become inflamed and

enlarged.• Laryngitis- inflammation of the larynx, leading to

the inability to talk in an audible voice.

Lower Respiratory Tract Infections• Acute bronchitis- infection of the primary and

secondary bronchi.• Pneumonia- a viral or bacterial infection of the

lungs in the which the bronchi and alveoli fill with thick fluid.

• Pulmonary tuberculosis- caused by the tubercle bacillus, a type of bacterium. They invade the lung tissue isolating them from the rest of the body.

The End:• Quiz Time!