Respiratory System

General Information Respiration - brings about exchange of gases (oxygen and carbon dioxide) between the blood, the air, and tissues Cellular respiration – the process that releases energy by breaking down glucose and other food molecules in the presence of oxygen, releasing carbon dioxide, and making ATP The respiratory system brings the oxygen to the cells and carries the carbon dioxide away

Structures of the Respiratory System Nose, pharynx, larynx, trachea, and bronchi Carry air to and from the lungs A. Nose – Where Oxygen first enters your body. Tiny hairs help filter the air and air is moistened and heated by your nose. Your Nose leads into your Nasal Cavity.

Pharynx Gathers air from your Nasal and Oral Cavities and passes it to your Trachea. Food, water and air can travel through this tube

Larynx Also called, “voice box” Made of cartilages Covered by epiglottis during swallowing Keeps solids, liquids out of airways Supports true vocal cords Exhaled air vibrates them to make sound

Trachea Also called “windpipe” Stiffened by C-shaped cartilage rings Esophagus stuck to posterior surface Cartilage missing there Trachea distorted by balls of food as they pass down esophagus to stomach

Lungs Bronchi Tubes- Each tube (one per lung) splits up into many smaller tubes called Bronchiole, like branches on a tree. Bronchiole- Keep splitting up until they reach your Alveoli. Composed of millions of tiny air sacs called alveoli which are rich with capillaries The alveoli are where gas exchange occurs

Structures of the Respiratory System 3. Breathing Movement of air into & out of the lungs Lungs have no muscle tissue Diaphragm contracts to form a partial vacuum to pull air into the lungs, the diaphragm relaxes to allow chest cavity to become smaller, making air flow out

Diseases of the respiratory system – many diseases result from smoking tobacco Nicotine – strong, toxic stimulant drug which increases heart rate and blood pressure (leading to cardiovascular disease) Carbon monoxide – poisonous gas which blocks the transport of oxygen and carbon dioxide in the blood

Tar – a carcinogen (causes cancer) Emphysema – loss of lung tissue elasticity

Review Homeostasis – the rate of breathing is controlled by the amount of carbon dioxide in the blood The level of carbon dioxide in the blood is monitored by the medulla oblongata of the brain

Review Increase in carbon dioxide tells the medulla to increase breathing rate until the level decreases When the medulla senses the decrease in carbon dioxide, this feedback to the medulla decreases the breathing rate