Massage Therapy Licensing Exam (MBLEx) Body Systems: Structure and Function Summary

Arteries carry blood away from the heart to the body. Their walls are thick and strong because the blood inside is under high pressure.

Wrong choices

• Veins: Veins carry blood back to the heart.
• Capillaries: Capillaries are tiny vessels where oxygen and food pass into the tissues.
• Lymph vessels: Lymph vessels carry lymph fluid, not blood.

The sympathetic nervous system gets the body ready for stress or danger. It raises heart rate and breathing and sends more blood to the muscles.

Wrong choices

• The parasympathetic nervous system: The parasympathetic system is "rest and digest". It calms the body.
• The somatic nervous system: The somatic system controls muscles you move on purpose.
• The lymphatic system: The lymphatic system is not part of the nervous system.

The lymphatic system collects extra fluid from the tissues and returns it to the blood. Its lymph nodes filter this fluid and hold white blood cells that fight infection.

Wrong choices

• Pump blood through the body: The heart pumps blood. The lymphatic system has no pump of its own.
• Carry oxygen to the cells: Red blood cells carry oxygen.
• Make hormones that control growth: Glands of the endocrine system make hormones.

A ligament joins bone to bone. It holds a joint together and keeps it stable.

Wrong choices

• Cartilage: Cartilage is a smooth tissue that covers bone ends and cushions joints.
• A tendon: A tendon joins a muscle to a bone.
• Fascia: Fascia is a sheet of connective tissue that wraps muscles and organs.

The femur is the bone of the thigh. It is the longest and strongest bone in the body and runs from the hip to the knee.

Wrong choices

• Tibia: The tibia is the large shin bone in the lower leg.
• Humerus: The humerus is the upper arm bone.
• Fibula: The fibula is the thin outer bone of the lower leg.

The skin covers the whole body, so it is the largest organ. It protects the body, helps control body heat, and senses touch.

Wrong choices

• The brain: The brain is much smaller than the skin.
• The liver: The liver is the largest organ inside the body, but the skin is larger overall.
• The lungs: The lungs are large, but smaller than the skin.

The left ventricle pumps oxygen-rich blood into the aorta and out to the body. It has the thickest wall of the four chambers because it does the hardest work.

Wrong choices

• The right atrium: The right atrium receives oxygen-poor blood coming back from the body.
• The right ventricle: The right ventricle pumps blood to the lungs to pick up oxygen.
• The left atrium: The left atrium receives blood from the lungs and passes it to the left ventricle.

In adults, red blood cells are made in the red bone marrow. Red marrow is found inside bones such as the hip bones, ribs, breastbone, and spine.

Wrong choices

• In the lymph nodes: Lymph nodes filter lymph and hold white blood cells.
• In the spleen: The spleen filters blood and removes old red blood cells.
• In the liver: The liver makes many proteins and bile, not red blood cells, in adults.

The somatic nervous system sends signals from the brain and spinal cord to the skeletal muscles. It controls the movements you choose to make, like lifting your arm.

Wrong choices

• The parasympathetic nervous system: The parasympathetic system is the "rest and digest" part of the autonomic system.
• The enteric nervous system: The enteric system controls the gut.
• The autonomic nervous system: The autonomic system runs things you do not control on purpose, such as heart rate.

The inferior vena cava is the large vein that carries blood from the legs, belly, and pelvis back to the right atrium. The superior vena cava does the same job for the upper body.

Wrong choices

• The great saphenous vein: The great saphenous vein runs up the inner leg and drains into the femoral vein, not the heart.
• The pulmonary vein: Pulmonary veins bring oxygen-rich blood from the lungs to the left atrium.
• The superior vena cava: The superior vena cava brings blood back from the head, neck, and arms.