Objectives

Path of food through the digestive system

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

Mechanical Digestion

Physical breakdown of food, including actions like chewing and churning.

Chemical Digestion

Enzyme breakdown of food, such as the action of amylase, pepsin, and lipase.

Where are carbohydrates digested?

In the mouth (amylase) and small intestine (pancreatic amylase).

Where are proteins digested?

In the stomach (pepsin) and small intestine (proteases).

Where are lipids digested?

In the small intestine (lipase), aided by bile from the liver/gallbladder.

Function of the Mouth in digestion

Ingestion, mechanical digestion, and initial chemical digestion.

Function of the Esophagus

Transports food to the stomach via peristalsis.

Function of the Epiglottis

Prevents food from entering the trachea.

Function of the Stomach

Chemical digestion (proteins), storage, and mixing.

Function of the Small Intestine

Major site of nutrient absorption.

Function of the Large Intestine

Water absorption and waste compaction.

Function of Salivary glands

Produce saliva (amylase) for carbohydrate digestion.

Function of the Liver

Produces bile for lipid digestion.

Function of the Gallbladder

Stores and releases bile for lipid digestion.

Function of the Pancreas

Secretes digestive enzymes and bicarbonate to neutralize stomach acid.

Structure of the Small Intestine

Villi and microvilli increase surface area for absorption; rich blood supply facilitates nutrient transport.

Organs of the Circulatory System

Heart, blood vessels (arteries, veins, capillaries), blood.

Functions of the Circulatory System

Transport of oxygen, nutrients, waste, hormones; temperature regulation.

Characteristics of Arteries

Thick walls that carry blood away from the heart under high pressure.

Characteristics of Veins

Thinner walls that carry blood to the heart under low pressure; contain valves.

Characteristics of Capillaries

Thin walls that are the site of gas and nutrient exchange.

Function of the Lymphatic System

Collects excess fluid (lymph), facilitates immune response, and aids in lipid absorption.

Path of blood flow (deoxygenated)

Right atrium -> Right ventricle -> Pulmonary arteries -> Lungs.

Path of blood flow (oxygenated)

Pulmonary veins -> Left atrium -> Left ventricle -> Aorta -> Body.

Components of blood

Red blood cells (oxygen transport), white blood cells (immune response), platelets (clotting), plasma (liquid matrix).

Diseases of the Circulatory System

Hypertension, heart attack, stroke.

Diseases of the Respiratory System

Asthma, pneumonia, bronchitis.

Organs of the Respiratory System

Nose/mouth, pharynx, larynx, trachea, bronchi, bronchioles, alveoli, lungs, diaphragm.

Gas exchange in the lungs

Oxygen diffuses from alveoli to blood; CO2 diffuses from blood to alveoli.

Gas exchange in tissues

Oxygen diffuses from blood to cells; CO2 diffuses from cells to blood.

Negative pressure breathing

Diaphragm contraction creates negative pressure, drawing air into the lungs.

Regulation of Breathing

Regulated by CO2 levels in the blood affecting the breathing rate.

Parts of a Rat's Digestive System

Esophagus, stomach, intestines.

Parts of a Rat's Circulatory System

Heart and major vessels.

Parts of a Rat's Respiratory System

Lungs and trachea.

Parts of a Rat's Excretory System

Kidneys.