ATI TEAS Human Anatomy and Physiology Summary

The left ventricle is the heart's strongest chamber. It pumps oxygen-rich blood into the aorta, the largest artery, which branches to carry blood to the whole body.

Wrong choices

• Pulmonary artery: The pulmonary artery carries oxygen-poor blood from the right ventricle to the lungs.
• Superior vena cava: This vein brings oxygen-poor blood from the upper body back to the right atrium.
• Pulmonary vein: Pulmonary veins bring oxygen-rich blood from the lungs into the left atrium, not out to the body.

Alveoli are tiny air sacs at the ends of the smallest airways. Their thin walls are surrounded by capillaries (tiny blood vessels), so oxygen moves into the blood and carbon dioxide moves out. This is called gas exchange.

Wrong choices

• Bronchi: Bronchi are large air tubes that carry air into each lung; gas exchange does not happen there.
• Trachea: The trachea (windpipe) only carries air to and from the lungs.
• Larynx: The larynx (voice box) holds the vocal cords.

On the arms and legs, proximal means closer to the trunk (or to where the limb attaches), and distal means farther away. The elbow is closer to the shoulder than the wrist is, so the elbow is proximal to the wrist.

Wrong choices

• Distal: Distal means farther from the trunk; the wrist is distal to the elbow, not the other way around.
• Anterior: Anterior means toward the front of the body, which does not describe this relationship.
• Deep: Deep means farther from the body surface.

Special cells in the pancreas release insulin, a hormone that helps cells take in glucose (sugar) from the blood. This lowers blood sugar after a meal.

Wrong choices

• Liver: The liver stores glucose and responds to insulin, but it does not make insulin.
• Thyroid gland: The thyroid makes hormones that control metabolism rate.
• Adrenal glands: The adrenal glands make hormones such as epinephrine (adrenaline) and cortisol.

Each kidney contains many nephrons. A nephron filters the blood, takes back what the body needs (such as water and glucose), and leaves waste behind to become urine.

Wrong choices

• Neuron: A neuron is a nerve cell.
• Alveolus: An alveolus is an air sac in the lung.
• Villus: A villus is a tiny finger-like fold in the small intestine.

Red blood cells contain hemoglobin, a protein that binds oxygen in the lungs and releases it in the tissues. Almost all of the oxygen in blood is carried this way.

Wrong choices

• Plasma: Plasma is the liquid part of blood; only a small amount of oxygen dissolves in it.
• White blood cells: White blood cells fight infection.
• Platelets: Platelets help blood clot.

The small intestine is lined with villi (tiny finger-like folds) that give it a huge surface area. Most digested nutrients pass through its walls into the blood here.

Wrong choices

• Stomach: The stomach mixes and starts breaking down food, but little is absorbed there.
• Large intestine: The large intestine mainly absorbs water and salts.
• Esophagus: The esophagus only moves food from the mouth to the stomach.

The right side of the heart sends oxygen-poor blood to the lungs.

1. Right atrium → right ventricle
2. Right ventricle → pulmonary artery → lungs (blood picks up oxygen)
3. Lungs → pulmonary veins → left atrium → left ventricle → aorta → body

Wrong choices

• Through the pulmonary veins to the left atrium: This happens later, after the blood has picked up oxygen in the lungs.
• Through the aorta to the body: The aorta leaves the left ventricle, not the right.
• Back into the right atrium: Valves keep blood from flowing backward into the atrium.

In negative feedback, the body's response reverses a change to bring conditions back to normal. A rise in temperature leads to sweating, which lowers the temperature. Most homeostasis (keeping the inside of the body stable) works this way.

Wrong choices

• During childbirth, contractions trigger the release of oxytocin, which causes even stronger contractions.: This is positive feedback, because the response makes the change bigger.
• As a clot forms, platelets release chemicals that attract more platelets.: This is also positive feedback, which builds up the change.
• A muscle grows larger after weeks of weight training.: This is a long-term change from training, not a feedback loop that returns the body to a set point.

The integumentary system is the body's outer covering: skin, hair, nails, and the sweat and oil glands in the skin. It protects the body, helps control temperature, and senses touch.

Wrong choices

• Lymphatic system: The lymphatic system includes lymph nodes and vessels.
• Skeletal system: The skeletal system is made of bones, cartilage, and ligaments.
• Endocrine system: The endocrine system is made of hormone-producing glands.