Respiratory System All I need is the air that I breathe
Men go abroad to wonder at the heights of mountains, at the huge waves of the sea, at the long courses of the rivers, at the vast compass of the ocean, at the circular motions of the stars, and they pass by themselves without wondering. St. Augustine
Gee Whiz Anatomy The average person will breathe about seventy five million gallons of air in a lifetime The alveoli cover a surface area of about 750 sq. ft. or about the size of a tennis court. The alveolus fills and empties about 15,000 times/day. On average we breath about 20 billion foreign particles per day. The resting breathing rate is about 12-14 breaths/minute; 20,000+ breaths/day. You have 300,000,000 alveoli in each lung
The Big Picture Conducting portion Respiratory portion
Functions Exchange of gases (O 2 and CO 2 ) Vocalization Protection Assists in the regulation blood ph. Contains receptors for the sense of smell
Fun Fact Respiratory system is lined with a mucous membrane (made of pseudostratified ciliated columnar E.T.) We make a quart of mucous per day
Overview of Structures Upper Respiratory Tract (URT) Nasal cavities Oral cavity Pharynx
Components of URT Nasal Cavities FXS Warm and moisten air Filters out dust and particulate matter by forming mucous traps SXS 2 halves, Rt and Lt separated by cartilaginous and bony medial septum 3 pairs of conchae (turbinates) increases surface area for mucous membranes 4 pairs of sinuses (make skull lighter and increase surface area
Components of URT (cont.) Pharynx Shared in part by the respiratory and digestive tracts Regions Nasopharynx Oropharynx Laryngopharyx
Overview of Structures (cont.) Lower Respiratory Tract (LRT) Larynx Trachea Bronchi Bronchioles Alveoli Pleurae (serous E.T.)
Components of LRT Larynx (voice box) Comprised of 9 cartilages Thyroid cartilage location of vocal cords Cricoid cartilage Epiglottis: elastic cartilage that forms a flap over larynx
Components of LRT (cont.) Trachea (windpipe) Fibro elastic tube (4.5 to 5.5 inches long) Extends from cricoid cartilage to primary bronchi C-shaped hyaline cartilaginous rings provide support
Components of LRT (cont.) Bronchi Primary (Rt. And Lt.) Roots of the lungs Secondary Right side has 3 branches Left side has 2 branches Tertiary Branch Bronchioles
Components of LRT (cont.) Lungs Organized like a sponge, not a balloon Right lung has 3 lobes, left lung has 2 lobes
Components of LRT (cont.) Bronchioles divide eventually into alveolar sacs These are surrounded by deadend sacs = alveoli (sing. = alveolus) Sxl and Fxl units of the lungs Exchange of gases occur here by diffusion Walls are simple squamous e.t. Surrounded by blood capillary network
Lungs are surrounded by serous membranes called pleurae Contain visceral and parietal parts Filled with pleural fluid to reduce friction
Ever Wonder?? Why Do I Yawn? When you are sleepy or drowsy the lungs do not take enough oxygen from the air. This causes a shortage of oxygen in our bodies. The brain senses this shortage of oxygen and sends a message that causes you to take a deep long breath---a YAWN. Why Do I Sneeze? Sneezing is like a cough in the upper breathing passages. It is the body's way of removing an irritant from the sensitive mucous membranes of the nose. Many things can irritate the mucous membranes. Dust, pollen, pepper or even a cold blast of air are just some of the many things that may cause you to sneeze. What Causes Hiccups? Hiccups are the sudden movements of the diaphragm. It is involuntary --- you have no control over hiccups, as you well know. There are many causes of hiccups. The diaphragm may get irritated, you may have eaten too fast, or maybe some substance in the blood could even have brought on the hiccups.
Respiratory Muscles Quiet Inhalation (Eupnea): produced by the diaphragm or external intercostals Exhalation: A passive action, caused by the relaxation of the above muscles