Respiratory System

Bryce Hennings & Brooke Taylor

Function

To supply oxygen and remove carbon dioxide from the blood as it circulates through the body.

Upper Respiratory Tract

• Consists primarily of the nose (nostrils and nasal passages)

• Mouth• Nasopharynx• Oropharynx• Laryngopharynx• Larynx

• These structures filter, warm, and humidify inspired air.

• Detects taste, smell, chewing and swallowing of food.

• Air enters through your nostrils where small hairs and mucus filter out dust and foreign particles.

• Air passes into two nasal passageways, separated by what is called the septum.

Nostrils and Nasal Passages

Nose Continued…

• Sinuses and nasopharynx: located in the frontal, sphenoid, and maxillary bones

• Sinuses provide speech resonance• Nasopharynx located behind nose and above

throat.

Oropharynx and Laryngopharynx

• Oropharynx posterior wall of mouth• It connects nasopharynx and laryngopharynx• Laryngopharynx extends to the esophagus

and larynx

• Contains the vocal cords and connects the pharynx with the trachea.

Larynx

Lower Respiratory Tract

• Consists of the trachea, bronchi, and lungs.• These structures contain a mucous

membrane with hair like cilia which lines the lower tract.

• Cilia cleans the tract.

Trachea

• Extends from the cricoid cartilage• C shaped cartilage rings that protect and

prevent it from collapsing

Bronchi

• The primary bronchi begin at the carina.• Right mainstream delivers air to the right

lung, left mainstream to the left.

• Secondary bronchi enter the pleural cavities and the lungs at the hilum and located behind the heart.

Alveoli

• Respiratory bronchioles eventually become alveolar ducts, which terminate in clusters of capillary-swathed alveoli.

Types:

• Type 1 cells are the most abundant. They are thin, flat, squamous cells that gas exchange occurs.

• Type 2 cells secrete surfactant, which is a substance that coats alveolus and promotes gas exchange by lowering surface tension.

Lungs

• Cone shaped, straddle the heart, anchored by root and pulmonary ligaments.

• Right lung is shorter, broader and larger.• 3 lobes (right) & handles 55% of gas exchange• 2 lobes (left)

Pleura and Pleural Cavities

• Pleura – membrane that totally encloses lung & composed of a visceral layer and parietal layer.

• Visceral pleura hugs entire lung surface.

Serous Fluid & Functions

• Pleural cavity - space between visceral and parietal layers contains a thin film of serous fluid which…

• Lubricates pleural surfaces• Creates a bond between the layers that

causes the lungs to move the chest wall when breathing.

Thoracic Cavity

• Area surrounded by diaphragm, the scalene muscles and fascia of the neck and ribs, intercostal muscles, vertebrae, sternum, and ligaments (around the circumference)

Mediastinum

• This is the space between the lungs which contains the…

• Heart and pericardium• Thoracic aorta• Pulmonary artery and veins• Venae cavae and azygos veins• Thymus, lymph nodes and vessels• Trachea, esophagus and thoracic duct• Vagus, cardiac, and phrenic nerves

Thoracic Cage

• It is composed of bone and cartilage which supports and protects the lungs, allowing them to expand and contract

• Posterior & anterior

How You Breathe

• http://youtu.be/NSEzg6TBheY

Inspiration and Expiration

• Breathing simply involves inspiration and expiration

• Both actions rely on respiratory muscle functions and effects of pressure

• Rising of the diaphragm and relaxation of the intercostal muscles causes and increase in intrapleural pressure, resulting in expiration

Normal

• External intercostal muscles aid the diaphragm

• Diaphragm descends to lengthen the chest cavity while intercostal muscles contract

• This causes a reduction in intrapleural pressure, resulting in inspiration

What Affects Breathing?

• Exercise is a major factor of determining breathing because when you exercise your body requires more oxygen

Continued…

• Forced inspiration: when all of your muscles involved in breathing contract while trying to let in more oxygen for the lungs

Continued…

• Active Expiration: internal intercostal muscles contract to shorten the chest’s diameter and depressing the ribs

Nervous System

• Involuntary breathing results from stimulation of the respiratory center in the medulla and the pons of the brain

• Monitors amounts of carbon dioxide in the blood (involuntarily)

• When carbon dioxide levels rise, the rate and depth of breathing increases to eliminate excess carbon dioxide

• Medulla also controls the contraction of the diaphragm which produce intrapulmonary pressure which causes inspiration.

• When the workload of your body is increased, efficiency is decreased.

• Occurs rapidly in millions of tiny alveoli.• Inside these air sacs, oxygen inhaled diffuses

into the blood while carbon dioxide diffuses from the blood into the air (exhaled).

• Then blood circulates throughout the body, delivering oxygen and picking up carbon dioxide.

• Finally blood returns to lungs to be oxygenated again.

Gas Exchange

Acid-Base Balance

• Oxygen taken up into the lungs is transported to the tissues by circulatory system

• Is then exchanged for carbon dioxide produced by metabolism in body cells

• Carbon dioxide can dissolve in blood which forms bicarbonate (base) and smaller amounts of carbonic acid (acid).

Most Common Forms of Lung Diseases…

• Asthma.• Bronchitis.• Chronic obstructive pulmonary disease

(COPD)• Emphysema.• Lung cancer.• Pneumonia.• Pulmonary edema.

Respiration Changes With Aging• Structural – lungs become more rigid, alveoli

number decreases as well as size.• 30% reduction in respiratory fluids which heightens the risk of pulmonary infection and

mucus plugs.• Closes airways due to poor ventilation

• Lung tissue degeneration

Works Cited

“Anatomy & Physiology made Incredibly Easy!” Fourth Edition. Google Images (Diagrams). Norris, Maggie and Siegfried Rae Donna. “Anatomy & Physiology for Dummies.”

"Organs Involved in the Respiratory System." Organs Involved in the Respiratory

System. Web. 29 Apr. 2015.

"Respiratory System | MyVMC." MyVMC. 26 June 2006. Web. 29 Apr. 2015.

"Respiratory System - Breathing; Inspiration (inhalation) and Expiration (exhalation)."

YouTube. YouTube. Web. 29 Apr. 2015.

"Structure of the Respiratory System." Structure of the Respiratory System. Web. 29 Apr.

2015.

"What Controls Your Breathing?" - NHLBI, NIH. Web. 29 Apr. 2015.