The Respiratory System SBI 3 U January 14

The Respiratory System SBI 3 U January 14 th, 2013

The Respiratory System �Exchange of oxygen and carbon dioxide between an organism and its external environment �Respiratory system: supplies oxygen to cells and removes carbon dioxide �CO 2 and breathing rate

More Respiratory Functions �Defends body against foreign pathogens �Controls p. H levels �Produces sounds for speaking �Helps maintain homeostasis

Components of Respiration �Ventilation or breathing �Inhalation and exhalation �Lungs: specialized structures for respiration (large surface area)

Components of Respiration �External Respiration �Exchange of gases across the respiratory surface between air sacs or alveoli and the blood �Respiratory surface – where oxygen diffuses into organism and CO 2 diffuses out

Components of Respiration �Internal Respiration �Exchange of gases between the blood in capillaries and individual cells in the tissues �Oxygen diffuses out of blood and CO 2 diffuses in

Components of Respiration �Occurs in the mitochondria �Glucose as fuel

Anatomy of Respiratory System �Upside down tree! �Begins with nasal cavity and ends at alveoli �Consists of: nose, nasal cavity, pharynx, larynx, trachea, smaller conducting passageways, and lungs

Nasal and Oral Cavities � 21% of every air inhalation is oxygen �Inhalation from mouth vs. nose �Nasal cavity: lined with mucus-secreting cells; helps to moisten and filter incoming air �Oral cavity

The Pharynx �Pharynx: common path for both air and food �Trachea/epiglottis �Larynx at top of trachea

The Larynx �Adam’s apple �Produces sound �Vocal chords: two highly elastic folds inside larynx

The Trachea �Windpipe �Allows air to pass from pharynx into lungs �Tough, flexible, c-shaped cartilage rings surrounds the trachea

Respiratory Structures Within the Chest Cavity � Trachea divides into 2 branches: right and left bronchi � Left bronchus Left lung � Right bronchus Right lung � Lungs � Bronchi branch into smaller tubes called bronchioles � Alveoli

Respiratory Structures Within the Chest Cavity �Bronchioles enter in a cluster of tiny hollow air sacs called alveoli � 150 million alveoli in each lung! �Occur in clusters �Gas exchange