Human Respiratory System Quiz

Alveoli are tiny air sacs in the lungs where oxygen from inhaled air diffuses into the blood, and carbon dioxide from the blood diffuses into the alveoli to be exhaled. They are adapted for gas exchange by being thin-walled (one cell thick), having a large surface area, and being densely surrounded by blood capillaries for efficient gas exchange.

The circulatory system's main function is to transport oxygen, nutrients, and waste products throughout the body. Arteries, with their thick walls, carry oxygen-rich blood away from the heart at high pressure. Veins, with thinner walls and larger lumens, carry oxygen-poor blood back to the heart. Capillaries, the smallest vessels, connect arteries to veins and allow for the exchange of gases, nutrients, and waste products between blood and tissues.

During exercise, the body's demand for oxygen increases. To meet this demand, the respiratory system responds by increasing breathing rate to deliver more oxygen to the lungs. Additionally, breathing becomes deeper, allowing for greater oxygen intake. This increased oxygen intake and removal of carbon dioxide helps the body sustain the increased energy needs of exercise.

<p>The digestive system breaks down food into nutrients the body can absorb. The mouth uses teeth and saliva to mechanically and chemically break down food. The esophagus transports food to the stomach, where it is further broken down by acid and enzymes. The small intestine absorbs nutrients into the blood, while the large intestine absorbs water and forms waste. The liver and pancreas produce enzymes and hormones that aid in the digestion of fats and regulate blood sugar.</p> Signup and view all the answers

<p>The diaphragm is a dome-shaped muscle that separates the chest cavity from the abdominal cavity. During inhalation, the diaphragm contracts and flattens, increasing the volume of the chest cavity and drawing air into the lungs. During exhalation, the diaphragm relaxes, returning to its dome shape, decreasing the volume of the chest cavity and forcing air out of the lungs.</p> Signup and view all the answers

<p>Blood is composed of red blood cells, which carry oxygen, white blood cells, which fight infection, platelets, which help with blood clotting, and plasma, which carries nutrients and waste. Each component plays a vital role in the circulatory system's function of transporting vital substances throughout the body.</p> Signup and view all the answers

<p>During exercise, the body's demand for oxygen increases. The circulatory system responds by increasing heart rate to pump more blood, carrying oxygen to muscles. Blood flow is also redistributed, with more blood being delivered to the working muscles and less to areas like the digestive system. This ensures that the muscles receive the necessary oxygen to sustain activity.</p> Signup and view all the answers

<p>The endocrine system produces hormones that regulate various bodily functions, including growth, metabolism, mood, and reproduction. For example, the pancreas releases insulin to regulate blood sugar levels, demonstrating the endocrine system's vital role in maintaining homeostasis and coordinating different bodily processes.</p> Signup and view all the answers

Provides oxygen to the body and removes carbon dioxide.

Lungs are the main organ where gas exchange happens.

Tiny air sacs where oxygen enters the blood and carbon dioxide leaves.

One cell thick for easy gas exchange, large surface area, and blood capillaries for diffusion.

Breaks down food into nutrients that the body can use.

Heart pumps blood around the body transporting oxygen, nutrients, and waste.

Cells that carry oxygen from the lungs to the body and carbon dioxide back to the lungs.

Produces hormones to regulate body functions.