Homeostasis and Body Systems

What is negative feedback?

A response that is opposite of the initial stimulus, often used as a mechanism of regulating body functions.

Organs/Structures of which you should know the function:

Alveoli Capillary(ies) Large Intestine Pancreas Teeth Anus Diaphragm Larynx Pharynx Trachea Artery(ies) Epiglottis Liver Rectum Ureter(s) Atria/Atrium Esophagus Lung(s) Salivary Gland(s) Urethra Bladder Gallbladder Mouth Small Intestine Vein(s) Bronchiole(s) Heart Nose Stomach Ventricles Bronchus/Bronchi Kidney

What is the functional unit of the respiratory system? Where is it located?

Alveoli, located inside the lungs at the end of the bronchioles

Compare/contrast the three types of blood vessels.

Arteries - Transport blood away from the heart, generally carry oxygenated blood, and have higher pressure that other vessels Veins - Transport blood to the heart, generally carry deoxygenated blood, and have valves to prevent backflow of blood (due to lower pressure) Capillaries - Walls are one cell thick, site of diffusion (functional unit)

The Left Ventricle has a thick muscle wall, why?

Because it has to be strong enough to pump blood to the whole body.

Define diffusion. Where does oxygen diffuse into your blood? Why does it diffuse?

Diffusion is the movement of molecules from an area of higher concentration to an area of lower concentration. Oxygen diffuses into your blood at the alveoli because there is a higher concentration of Oxygen in your alveoli as compared to your deoxygenated capillaries, so oxygen easily diffuses down its concentration gradient from the alveoli to the capillaries.

Describe how two systems work together to get nutrients to every cell.

Digestive and circulatory systems do this. First, food is ingested, then digested, then absorbed in the small intestine. The nutrients diffuse into the capillaries surrounding the microvilli of the small intestine where it is transported to the liver and then to the rest of the body to bring nutrients to all cells.

What is the function of the respiratory system?

Exchange of gases (Oxygen for Carbon Dioxide)

What are the major structures of the circulatory system?

Heart Blood Vessels (Arteries, Veins, Capillaries) Blood

What does the diaphragm do when you inhale?

It contracts and becomes flatter

What are the major structures of the urinary/excretory system?

Kidney, Ureters, Bladder, Urethra

What is the pathway of blood through the heart, body, and lungs, starting with the Left Ventricle?

Left Ventricle brings blood through the aorta, which carries oxygenated blood to each of the body cells. As the oxygen diffuses from the red blood cells into the body cells and carbon dioxide diffuses from the body cells into the blood plasma, the blood is then carried back to the right atrium. From this chamber, the deoxygenated blood travels down to the right ventricle and through the pulmonary arteries to the lungs where it becomes oxygenated. It is then passed through the pulmonary veins, back to the heart via the left atrium.

What is the function of the urinary/excretory system?

Maintain salt and water balance and get rid of nitrogenous wastes.

Define Homeostasis:

Maintaining a stable, internal environment

Give 3 examples of homeostasis in the Human Body:

Maintenance of heart rate Maintenance of blood pressure Maintenance of body temperature

Describe the two types of digestion:

Mechanical Digestion - Breaking food down into smaller pieces Chemical Digestion - Breaking the bonds of food

What is the function of the digestive system?

Mechanical and chemical breakdown of food and absorption of nutrients

What are the major structures of the digestive system?

Mouth, Pharynx, Esophagus, Stomach, Liver, Gallbladder, Pancreas, Small Intestine, Large Intestine, Rectum, Anus

What is the pathway of food through the digestive system?

Mouth, Pharynx, Esophagus, Stomach, Small Intestine, Large Intestine, Rectum, Anus

What are the major structures of the respiratory system?

Nasal cavity, Oral Cavity, Pharynx, Larynx, Trachea, Bronchi, Bronchioles, Alveoli, Diaphragm

What is the pathway of air through the body?

Nasal cavity/Oral Cavity → Pharynx → Larynx → Trachea → Bronchi → Bronchioles → Alveoli

What is the functional unit of the urinary/excretory system? Where is it located?

Nephrons, located in the kidneys

What two systems regulate the functions of the circulatory, respiratory, digestive, and urinary/excretory systems?

Nervous System Endocrine System

What does a functional unit do for the system to which it belongs?

Provide large amounts of surface area for the diffusion of materials.

You eat a cheeseburger. Describe how and where the burger (protein), the cheese (fat), and the bun (carbohydrates) are broken down.

The cheeseburger makes its way into your mouth where your teeth mechanically start to break down the cheeseburger. Your salivary glands produce a mucus that contains amylase, an enzyme that breaks down the bun (carbohydrates). This bolus of food makes its way down your esophagus and into the stomach, where an enzyme called pepsin breaks down the proteins of the burger. This chyme continues on to your small intestine, where the pancreatic juices and bile, from your pancreas and gallbladder, respectively, provide the means to digest the fatty cheese.

Describe how two systems work together to get nitrogenous waste out of every cell.

The circulatory and urinary systems do this together. As nitrogenous waste from breaking down proteins is picked up by the blood cells, it travels all over the body and eventually passes through capillaries in the glomerulous of the nephron in the kidney. Waste is filtered out into the nephron and is converted into urine, and excreted through the urethra.

Describe how two systems work together to get oxygen to every cell and carbon dioxide waste out of every cell.

The respiratory and circulatory systems do this by exchanging gases (carbon dioxide and oxygen) between the capillaries surrounding the alveoli in the lungs. The blood then carries oxygen to the rest of the body where it delivers it to the cells and picks up carbon dioxide waste from each cell. Carbon dioxide is then brought back to the capillaries around the alveoli where it diffuses out into the lungs and replaced with oxygen.

What is the function of the circulatory system?

To TRANSPORT necessary materials (Oxygen and nutrients) to every cell and unnecessary materials (Carbon Dioxide and nitrogenous wastes) away from every cell.

What is the functional unit of the digestive system? Where is it located?

Villi, located in the second and third sections of the small intestine

Give an example of negative feedback that occurs in the body.

When your body temperature lowers, your skin receptors send messages to your brain to shiver and constrict blood vessels to aid in increasing your body temperature back to the set point (about 98.6 degrees Fahrenheit).

What is the functional unit of the circulatory system?

capillaries

In which organ does the majority of digestion and absorption take place in the digestive system?

small intestine