Respiratory System Overview

Respiratory System

• Organs and Functions:

  • Nose: Filters, warms, and moistens inhaled air.
  • Pharynx: Passageway for air and food, also involved in warming and moistening.
  • Trachea: A tube keeping air passageway open, cleaning incoming air.
  • Bronchi: Branching tubes leading to lungs, further dividing into bronchioles, ending in alveoli.
  • Lungs: Contain bronchi, bronchioles, and alveoli, the site of gas exchange.

• Air Pathway (Inhalation/Exhalation):

  • Inhalation: Nose → Pharynx → Trachea → Bronchi → Lungs.
  • Exhalation: Lungs → Bronchi → Trachea → Pharynx → Nose.

• Breathing Muscles and Action:

  • Intercostal Muscles: Located on ribs, lift the rib cage to expand the lungs.
  • Diaphragm: Flattens to lower lung pressure, drawing air in.

• Breathing vs. Cellular Respiration:

  • Breathing: Movement of air into and out of lungs.
  • Cellular Respiration: Process using oxygen and glucose to create energy, producing carbon dioxide as a byproduct.

• Respiratory System Goal:

  • Obtain oxygen for cellular respiration.
  • Remove carbon dioxide, a cellular respiration waste product.

Circulatory System

• Goal: Transport materials (oxygen, glucose) to cells and remove waste (carbon dioxide, water).

• Heart Structures and Function:

  • Atria: Receive blood into the heart.
  • Ventricles: Pump blood away from the heart.
  • Valves (Tricuspid, Pulmonary, Mitral, Aortic): Ensure one-way blood flow.
  • Septum: Divides the heart into left and right sides.

• Heart Action:

  • Diastole (Phase 1): Heart relaxes, fills with blood.
  • Systole (Phase 2): Heart contracts, pumps blood out.

• Pathway of Blood Through the Heart:

  • Right atrium → Right ventricle → Pulmonary artery → Lungs;
  • Lungs → Pulmonary veins → Left atrium → Left ventricle → Aorta → Body;
  • Body → Superior/Inferior Vena Cava → Right atrium.

• Blood Vessels and Functions:

  • Arteries: Carry blood away from the heart.
  • Veins: Return blood to the heart.
  • Capillaries: Tiny vessels, site of gas and nutrient exchange.

• Blood Vessel Structure Differences:

  • Arteries: Thick, muscular walls to withstand high pressure.
  • Veins: Thinner walls, valves to prevent backflow.
  • Capillaries: Extremely thin walls for efficient gas exchange.

• Closed System: Circulatory system is a closed loop, blood circulates continuously without leaving the system.

• Two-Loop System:

  • Pulmonary Circulation: Right side pumps blood to lungs for oxygen uptake.
  • Systemic Circulation: Left side pumps oxygenated blood to the body for cellular use.

Interrelationship

• Respiratory and Circulatory Systems: Work together delivering oxygen and removing carbon dioxide to support cellular respiration.

  • Respiratory system provides oxygen to the capillaries in the alveoli.
  • Circulatory system transports carbon dioxide to the lungs via capillaries for removal.

• Levels of Organization:

  • Cells → Tissues → Organs → Organ Systems → Organism

• Homeostasis:

  • Body maintains stable internal conditions (e.g., temperature regulation).
  • Body adjusts through various mechanisms (e.g., shivering to increase temperature).