Human Respiratory System Overview

Respiratory System Overview

• Breath is essential for life, marking dramatic moments of human experience.
• Respiration is critical for ATP production, which is necessary for metabolism.
• The process generates carbon dioxide, which must be removed and oxygen delivered for the process.

Respiratory System Function

• The respiratory system consists mainly of tubes leading air to the lungs.
• Oxygen diffuses into the blood, and carbon dioxide is removed.
• Respiration has other roles beyond gas exchange, including communicating, smelling and regulating blood pressure.
• The Respiratory system consists of the upper and lower respiratory systems. The respiratory system has other vital functions like regulating blood pressure, smell and communication.

Parts of the Respiratory System

• Upper respiratory tract: Nose, nasal cavity, pharynx (throat), larynx (voice box)
• Lower respiratory tract: Trachea (windpipe), bronchi, bronchioles, alveoli (air sacs)
  • The conducting zone is for airflow, no gas exchange occurs
  • The respiratory zone for gas exchange.

Nose (Nasus)

• Warms, cleanses, and humidifies inhaled air.
• Detects odors.
• Resonating chamber amplifying the voice.
• Consists of bone and cartilage.
• The nasal cavity is divided by the nasal septum.
• Contains conchae to increase surface area for warming and filtering.

Pharynx (Throat)

• Common passageway for air and food.
• Muscular funnel extending from the nasal cavity and mouth to the larynx and esophagus.
• Divided into three parts: nasopharynx, oropharynx, and laryngopharynx.

Larynx (Voice Box)

• Cartilaginous structure at the top of the trachea.
• Protects the airway during swallowing.
• Responsible for sound production.
• Vocal cords are located in the larynx.
• During swallowing, the epiglottis covers the trachea to prevent food from entering.

Trachea (Windpipe)

• Tube extending from the larynx to the bronchi.
• Supported by C-shaped cartilaginous rings to prevent collapse.
• Transports air to and from the lungs.
• Divides into two main bronchi.

Bronchi and Bronchioles

• Branches of the trachea, conducting air to individual lung lobes and then smaller airways.
• Branching continues to smaller bronchioles.
• Bronchioles lead to alveoli, the sites of gas exchange.

Alveoli

• Tiny air sacs within the lungs.
• Site of gas exchange (oxygen and carbon dioxide).
• Thin walls permit rapid diffusion of gases.
• Greatly increase surface area for gas exchange.

Lungs

• Two cone-shaped organs located in the thoracic cavity.
• Encased in pleura, a double-layered membrane.
• The lungs contain alveoli and bronchi.
• The lung's root contains vessels, nerves, and the bronchi entering and exiting the lungs.

Pleura

• Double-layered membrane surrounding the lungs. The visceral pleura is internal and parietal is external.
• Reduces friction during breathing.
• Creates a pressure gradient for lung inflation.

Root of the Lungs

• Structures entering and leaving the lungs.
• Contains bronchi, blood vessels, nerves, and lymphatic vessels.
• Allows for communication and transport to and from the lungs.

Lobes of the Lungs

• Right lung has three lobes: superior, middle, and inferior.
• Left lung has two lobes: superior and inferior.
• Lobes are separated by fissures (grooves).