The immune system protects the body against infections and diseases by identifying and destroying pathogens.

The skeletal system provides structure and protection for internal organs, making option 2 the correct answer.

Red blood cells are primarily responsible for transporting oxygen from the lungs to the rest of the body, making option 2 the correct answer.

The digestive system breaks down food into nutrients, which are then absorbed into the bloodstream for energy.

The circulatory system is responsible for transporting nutrients, oxygen, and waste products throughout the body.

The primary function of the digestive system is to break down food and absorb nutrients, making option 1 the correct answer.

The integumentary system, which includes the skin, hair, and nails, serves to protect the body, regulate temperature, and provide sensory information.

The primary function of the respiratory system is to exchange gases, specifically to take in oxygen and expel carbon dioxide.

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

The circulatory system's role is to transport nutrients, oxygen, and hormones to cells and remove waste products.

The respiratory system is responsible for the exchange of gases, primarily oxygen and carbon dioxide, between the body and the environment.

The somatic nervous system controls voluntary movements, making option 3 the correct answer.

The pancreas plays a role in digestion by producing digestive enzymes and also functions as an endocrine organ by producing insulin.

The small intestine is the main site for the absorption of nutrients from digested food.

The kidneys filter blood to remove waste and excess substances, producing urine.

The kidneys are responsible for filtering blood, removing waste products and excess substances to form urine.

The pancreas produces insulin, which helps regulate blood sugar levels in the body.

The medulla oblongata controls autonomic functions such as heart rate and breathing.

The medulla oblongata controls autonomic functions, including heart rate and breathing.

The autonomic nervous system controls involuntary actions such as heart rate, digestion, and respiratory rate.

The endocrine system is primarily responsible for hormone production and regulation in the body.

The muscular system is responsible for movement by contracting and relaxing muscles.

The endocrine system is responsible for producing and secreting hormones that regulate various bodily functions.

The endocrine system is responsible for producing and secreting hormones that regulate various bodily functions.

The muscular system is responsible for movement in the body, working in conjunction with the skeletal system.

The endocrine system produces hormones that regulate various functions in the body.

The immune system is responsible for the body's defense against infections and diseases.

Both the nervous and endocrine systems work together to manage the body's response to stress.

The endocrine system produces hormones that regulate various functions in the body, including growth, metabolism, and mood.

The endocrine system produces hormones that regulate various functions in the body.