organ system

Digestive System

Breaks down food into nutrients for absorption and energy.

Digestive System Purpose

The primary function is to break down food into nutrients that can be absorbed by the body for energy.

It also plays a crucial role in removing solid waste from the body, ensuring proper waste management.

Mouth

Mechanical digestion (chewing); saliva begins chemical digestion of carbohydrates.

Esophagus

Muscular tube that pushes food to stomach via peristalsis.

Stomach

Mixes food with gastric juices; protein digestion starts here.

Small Intestine

Main site of nutrient absorption.

Duodenum

Digestion.

Jejunum/Ileum

Absorption.

Large Intestine (Colon)

Absorbs water and forms feces.

Rectum/Anus

Stores and eliminates feces.

Liver

Produces bile (digests fats), detoxifies chemicals.

Gallbladder

Stores and releases bile into small intestine.

Pancreas

Produces digestive enzymes and bicarbonate.

Amylase

Digests starch.

Pepsin

Digests proteins.

Lipase

Digests fats.

Bile

Emulsifies fats.

Circulatory System

Transports oxygen, nutrients, hormones, and waste throughout the body.

Circulatory System Purpose

Maintains body temperature and pH.

Heart

Pumps blood.

Blood vessels

Includes arteries (carry blood away from the heart), veins (carry blood to the heart), and capillaries (sites of gas and nutrient exchange).

Veins

Carry blood to the heart.

Capillaries

Site of gas and nutrient exchange.

Blood Flow Pathway

Body → Vena Cava → Right Atrium → Right Ventricle → Pulmonary Arteries → Lungs → Pulmonary Veins → Left Atrium → Left Ventricle → Aorta → Body.

Red Blood Cells (RBCs)

Carry oxygen using hemoglobin.

White Blood Cells (WBCs)

Defend against infection.

Platelets

Help with clotting.

Plasma

Liquid part; carries nutrients, hormones, waste.

Respiratory System

Supplies oxygen to the blood and removes carbon dioxide. REMEMBER GAS EXCHANGE

Nasal cavity

Warms, moistens, and filters air.

Pharynx

Connects nose/mouth to trachea.

Larynx

Voice box.

Trachea

Windpipe; carries air to lungs.

Bronchi

Two branches leading to each lung.

Bronchioles

Smaller branches in lungs.

Alveoli

Tiny sacs for gas exchange with capillaries.

Inhalation

Diaphragm contracts and moves down; ribcage expands; air flows into lungs.

Exhalation

Diaphragm relaxes and moves up; air pushed out.

Gas Exchange

Occurs in alveoli; oxygen diffuses into blood; carbon dioxide diffuses into alveoli to be exhaled.