Principles of Health Science - Body Systems

Cardiovascular, Respiratory, and Digestive Systems

The purpose of the Digestive system

The absorption of nutrients into the body for the cells to use.

The parts of the digestive system

The gastrointestinal tract (aka GI Tract / Alimentary Canal) and accessory organs.

What the gastrointestinal tract is

A pathway that food moves through from ingestion to defecation; Spans 16-23 feet in a living person but 23-30 feet in a cadaver (relaxed).

What accessory organs are

Organs that help break down food but food doesn’t enter them.

What is the is the entire gastrointestinal tract

Mouth > Pharynx > Esophagus > Stomach > Small Intestine > Large Intestine > Rectum > Anus.

What are the processes of digestion

Ingestion (eating; mouth only)

Secretion (digestive system creates 7 liters of fluids daily)

Propulsion (swallowing and peristalsis [smooth muscle] pushes food throughout the tract)

Digestion (Chemical [enzymes] and mechanical [force] break down of food)

Absorption (the passing of nutrients into the blood stream)

Defecation (unabsorbed materials [feces] are eliminated)

The purpose of the Cardiovascular system

The transportation of blood to and from every living cell in the body.

What does blood deliver to cells

Oxygen, nutrients, water, hormones, and white blood cells.

What does blood remove from cells

Waste (CO₂)

The parts of the cardiovascular system

The heart, blood, and blood vessels.

What the heart is

A pump made of cardiac muscle and beats approx. 72 times per minute; made of 4 chambers (the Atriums [top], and Ventricles [bottom])

What the blood is

Made of cells and plasma, which transports (RBCs and plasma), fights infections (WBCs), and clots (Platelets).

What blood vessel carries blood away from the heart?

Arteries carry oxygenated blood away from the heart to the body cells.

What is blood pressure

Systolic - The maximum force against the artery walls while the heart pumps blood

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Diastolic - The minimum force when the heart relaxes and refills with blood

The purpose of the Respiratory system

The delivery of oxygen and removal of CO₂ to and from the body

The importance of oxygen

Oxygen is used to complete cellular respiration which creates ATP (fuel for cells)

What are the processes of respiration

Pulmonary Ventilation, External Respiration, Transportation, and Internal Respiration.

What is pulmonary ventilation

Inspiration / inhalation / breathing in where air moves into the lungs from the atmosphere and Expiration / exhalation / breathing out where air moves out of the lungs into the atmosphere.

What is external respiration

Happens in the lungs (Alveoli) where O₂ diffuses out of the lungs into the blood and CO₂ diffuses into the lungs from the blood.

What is transportation

The cardiovascular system transports gases (CO₂ and O₂) from the lungs to the tissue cells (O₂) and from the tissue cells to the lungs (CO₂).

What is internal respiration

Happens in the cells