The main function of the skeletal system is to provide support and protection for the body's organs and tissues.

The main function of the stomach is to perform mechanical and chemical digestion of food.

Hemoglobin primarily transports oxygen from the lungs to the tissues and helps carry carbon dioxide back to the lungs.

The circulatory system's main purpose is to transport nutrients, oxygen, and waste products throughout the body.

The main purpose of the circulatory system is to transport blood, nutrients, gases, and waste products throughout the body.

The coronary arteries supply blood to the heart muscle itself, providing it with oxygen and nutrients.

The main purpose of pulmonary circulation is to exchange gases in the lungs, allowing carbon dioxide to be expelled and oxygen to be absorbed.

Villi increase the surface area of the small intestine, enhancing nutrient absorption.

The pH level of gastric acid in the human stomach typically ranges from 1 to 2.

The Animal Kingdom is primarily defined by multicellularity, which distinguishes animals from unicellular organisms.

The atrioventricular (AV) node follows the SA node in the heart's conduction system, relaying impulses to the ventricles.

The nasal cavity is responsible for filtering, warming, and humidifying the air before it enters the lungs.

Bilateral symmetry allows for increased mobility and streamlined movement, which is advantageous for predation and escape.

Bile emulsifies fats, making them easier to digest and absorb in the small intestine.

Gastric acid primarily breaks down proteins and activates digestive enzymes in the stomach.

Red blood cells are primarily responsible for transporting oxygen from the lungs to the body's tissues.

The primary function of red blood cells is to transport oxygen from the lungs to the body's tissues.

The alveoli are tiny air sacs in the lungs where the exchange of oxygen and carbon dioxide occurs.

The primary function of the circulatory system is to transport oxygen and nutrients to cells and remove waste products.

The primary function of the circulatory system is to transport nutrients and oxygen to cells and remove waste products.

The coronary arteries supply oxygenated blood to the heart muscle itself, ensuring it receives the nutrients needed for contraction.

The corpus luteum primarily produces progesterone, which helps maintain the uterine lining during early pregnancy.

The epiglottis is a flap that covers the trachea during swallowing, preventing food and liquids from entering the airway.

The primary function of the excretory system is to remove waste products from the body, maintaining homeostasis.

The exoskeleton in arthropods provides support and protection, allowing them to maintain their shape and protect against predators.

The nasal cavity filters, warms, and humidifies the air before it enters the lungs.

Nephridia are excretory organs in annelids that help in the removal of waste products from the body.

The ovaries are responsible for producing eggs (ova) and hormones such as estrogen and progesterone.

The placenta serves as the interface between the mother and fetus, providing essential nutrients and oxygen while removing waste products.

The primary function of the respiratory system is gas exchange, allowing oxygen to enter the body and carbon dioxide to be expelled.