Respiratory System. Main Function Gas Exchange –To work closely with the cardiovascular system to supply the body with oxygen and to dispose of carbon.

Respiratory System

Main Function

• Gas Exchange

– To work closely with the cardiovascular system to supply the body with oxygen and to dispose of carbon dioxide

Organs Include1. Nose2. Pharynx3. Larynx4. Trachea5. Bronchi

– And their smaller branches

6. Lungs– Containing

alveoli (terminal sacs)

The Nose

• Externally visible – Nostrils – External

Nares– Internally – Nasal

Cavity– Divided by nasal

septum– Olfactory receptors in

the superior cavity in the mucosa

Function of Nose• Mucosa lining rests on thin walled veins that warm the air• Mucous produced by the mucosa, moistens the air and traps

bacteria and other particulates

Bone Structures

• Conchae- Increase surface area of mucosa and create turbulance

• Palate- Separates from oral cavity– Hard palate (bone ) is

anterior– Soft palate(tissue) is

posterior

Cleft Palate

• Genetic Defect• Bones do not

fuse medially• Causes

Problems:– Breathing – Chewing– Speaking

Paranasal Sinuses

• Surround the nasal cavity

• Located in Bones:– Frontal– Sphenoid– Ethmoid– Maxillary

Function of Sinuses

• Lighten the skull• Resonance for

speech• Produce

mucous• Nasolacrimal

ducts– Drain tears from

eyes

Rhinitis, Sinusitis, Sinus Headache

• Inflammation of the nasal mucosa– Virus– Allergens

• Mucosa is continuous so that these infections often spread

Pharynx

• 13cm muscular passageway (Throat)

• Food and air• Nasopharynx-

Superior• Oropharynx-

central• Laryngopharynx-

Inferior

Pharynx

• Tonsils are located in the pharynx– Pharangeal or

Adenoids (superior)

– Palatine (oropharynx)

– Lingual (base of tongue)

Larynx• AKA Voice box, routes air,

role in speech• Inferior to pharynx• Eight rigid hyaline cartilage

– Largest is Thyroid cartilage (Adam’s Apple)

– Protrusion angel 90˚ in males and 120˚ in females

• Cartilage flap – Epiglottis protects opening

Larynx

• Mucous Membrane forms Vocal folds (vocal cords)

– allow us to speak• Glottis - Slit-like

passageway between the vocal folds

Trachea

• Windpipe• Goes to the 5th

Thoracic Vertebrae• Reinforced with C-

shaped cartilage rings to keep it open anteriorly and allow flexibility for food to pass through the esophagus posteriorly

Airway Obstruction

• Heimlich Maneuver– Physical Procedure

where someone assists in dislodging a blockage

• Tracheostomy– Surgical Procedure

cuts a new opening

Main Bronchi

• Division of the trachea

• Runs obliquely• Ends at the hilus

(medial depression of the lung)– The right is wider and

shorter and more often the site of inhaled objects

Lungs

• Occupy entire thoracic cavity (except mediastinum where the heart is)

• Narrow superior portion (apex) is deep to clavicle

• Broad base rests on the diaphragm

• Left lung = 2 lobes• Right lung = 3 lobes

Lungs

• Surface covering is visceral serosa called Pulmonary Pleura

• Walls of the cavity are covered with parietal pleura

• Pleural fluid reduces friction during breathing movements

Pleurisy

• Inflammation of the pleura due to decreased secretion of pleural fluid

• Pain with each breath

• Excess fluid may hinder breathing

Bronchioles

• Primary bronchi subdivide into smaller branches

• Bronchial Tree– Secondary

Bronchi– Tertiary Bronchi– Then Bronchioles

Alveoli

• Small cavity or air sac– Millions of clustered

alveoli look like bunches of grapes

• Site of gas exchange• Make up a bulk of the

lungs– Also stroma which is

elastic

Respiratory Membrane

• Thin squamous epithelial cells

• Alveolar pores connect sacs

• External surfaces have a “cobweb” of capillaries

• Respiratory Membrane is the Air / Blood barrier