Organs of Respiration Function of the Respiratory System Nose Pharynx (throat) Larynx (voice box) Trachea (windpipe) Bronchi Lungs - alveoli Passageways purify, warm, and humidify the incoming air Exchange of CO2 and O2 between the blood and external environment

Anatomy of the Nasal Cavity Olfactory receptors (smell) are located in the mucous membranes that line the superior surface of the nasal cavity The rest of the cavity is lined with respiratory mucosa Moistens air Traps incoming foreign particles Ciliated cells move contaminated mucosa to the throat (pharynx) so you can spit it out. Blood vessels are close to the surface 

Anatomy of the Nasal Cavity Lateral walls have projections called conchae Conchae increase the surface area Conchae increase air turbulence within the nasal cavity The nasal cavity is separated from the oral cavity by the palate (roof of the mouth) Anterior hard palate (bone) Posterior soft palate (muscle)

What causes nose bleeds? Spontaneous nosebleeds are fairly common, especially in children. When the mucous membrane inside the nose dries, crusts, or cracks (the skin splits open) and is then picked, it is likely to bleed. Because the nose is full of blood any minor injury to the face can cause the nose to bleed profusely.

Cleft Lip/Palate Cleft lip, with or without cleft palate, affects one in 700 babies annually, and is the fourth most common birth defect in the U.S. In most cases, the cause of cleft lip and cleft palate is unknown. These conditions cannot be prevented. Most scientists believe clefts are due to a combination of genetic and environmental factors.

Cleft Lip A cleft lip is a physical split or separation of the two sides of the upper lip and appears as a narrow opening or gap in the skin of the upper lip. This separation often extends beyond the base of the nose and includes the bones of the upper jaw and/or upper gum

Cleft Lip

Cleft Palate A cleft palate is a split or opening in the roof of the mouth. A cleft palate can involve the hard palate and/or the soft palate.

Cleft Palate

Paranasal Sinuses Cavities within bones surrounding the nasal cavity Frontal bone Sphenoid bone Ethmoid bone Maxillary bone

Function of the Sinuses Lighten the skull Act as resonance chambers for speech Produce mucus that drains into the nasal cavity

common passageways for air and food Pharynx (Throat) Muscular passage from nasal cavity to larynx Three regions of the pharynx Nasopharynx – superior region behind nasal cavity Oropharynx – middle region behind mouth Laryngopharynx – inferior region attached to larynx common passageways for air and food

Structures of the Pharynx Eustachian tubes link the nasopharynx to the middle ear. The Eustachian tubes drain mucus from the middle ear. Upper respiratory tract infections or allergies can cause the Eustachian tubes to become swollen, trapping fluid, which serves as a growth medium for bacteria, causing ear infections (otitis media) Oto- = ear; -itis = inflamation; media = middle Inflamation of the middle ear

Ear Wax

Structures of the Pharynx Your tonsils are part of your lymphatic system. They help protect you from infection by trapping germs coming in through your mouth and nose Pharyngeal tonsil (adenoids) in the nasopharynx Palatine tonsils in the oropharynx – these are the ones at the back of your throat that you can see tonsillitis – inflammation of the tonsils Lingual tonsils at the base of the tongue

Tonsillectomy

Larynx (Voice Box) Functions: 1) Routes air and food into proper channels and 2) allows you to produce sound (speech) Made of eight rigid hyaline cartilages and a spoon-shaped flap of elastic cartilage (epiglottis)

Structures of the Larynx Upper opening of the larynx Directs food to the esophagus and air to the trachea Made of hyaline cartilage Commonly called the Adam’s apple

Structures of the Larynx, cont’d Vocal cords Vibrate with expelled air to create sound (speech) Glottis – opening between vocal cords

Trachea (Windpipe) Connects larynx with bronchi Lined with ciliated mucosa Cilia beat continuously in the opposite direction of incoming air to get rid of mucus loaded with dust and other debris Don’t want this stuff in the lungs Walls of trachea are reinforced with C-shaped hyaline cartilage oles Right bronchus is wider, shorter, and straighter than left

Lungs Occupy most of the thoracic cavity Apex is near the clavicle (superior portion) Base rests on the diaphragm (inferior portion) Each lung is divided into lobes by fissures Left lung – two lobes Right lung – three lobes

Coverings of the Lungs Parietal pleura lines the walls of the thoracic cavity Visceral (pulmonary) pleura covers the lung surface Pleural cavity between the pleura filled with pleural fluid to reduce friction

Alveoli Gas exchange takes place within the alveoli in the respiratory membrane

Gases move by DIFFUSION Respiratory Membrane Simple squamous epithelium Simple squamous epithelium Gases move by DIFFUSION

Gas Exchange Gas crosses the respiratory membrane by DIFFUSION Moving from an area of high concentration to an area of low concentration Oxygen moves from the alveoli to the bloodstream Carbon dioxide moves from the bloodstream to the alveoli

Alveoli = high concentration of O2 in here; low CO2 Capillary = high concentration of CO2 in here; low O2