The Human Body

Human Organ Systems Notes

I can identify the systems of the human body. I can identify the function of the human body systems. I can explain how the body systems work together. I can identify the major organs in each of the human body systems.

What is an organ? Give an example. What are the organ systems in the human body?

Organs An organ system is made of a group of organs that work together to perform a specific function. Organs are a group of tissues that work together to perform a function.

What is the purpose of the digestive system? List the organs found in the digestive system. Where do you think digestion begins?

Digestion begins in the mouth where food is chewed. The Digestive System The digestive system converts food into simpler molecules that can be sued by body cells. In addition to breaking down food, the digestive system also absorbs nutrients. Digestion begins in the mouth where food is chewed.

What is the path food takes through the digestive system? Predict what you think happens to food in the stomach.

When food is swallowed, it moves through the esophagus to the stomach. The Digestive System When food is swallowed, it moves through the esophagus to the stomach. The stomach acts like a giant blender, mixing everything together. Once food is mixed, it moves to the small intestine where most digestion occurs.

Where do you think most digestion takes place? Review: What is an enzyme?

Digestion requires enzymes. The Digestive System Digestion requires enzymes. Remember, enzymes are proteins that work based on shape, like a puzzle piece. In the small intestine, carbohydrates are converted to glucose, fats are broken down, and proteins are broken down into amino acids.

The digestive system provides the nutrients that we need to survive. These nutrients are then absorbed into the blood stream in the small intestine. The digestive system provides the nutrients that we need to survive.

The Digestive System The remaining material in the small intestine moves to the large intestine. In the large intestine, water and vitamins are absorbed into the blood stream, and the remaining material is removed from the body as waste.

What is the purpose of the respiratory system? What organs are found in the respiratory system? Why do we need oxygen?

The Respiratory System The respiratory system provides oxygen for cells and removes CO2 from the body. Oxygen is required for cellular respiration, which provides energy for cells. Air can enter or leave the body through the mouth or nose.

Which would be better to breathe in and out of: your nose or your mouth? Why? How does air get from your mouth to your lungs (what is the path)?

The Respiratory System The nose is a better choice because it is lined with hair, called cilia. The cilia filter dirt and microorganisms out of the air we breathe. Once air enters the body, it moves through the trachea to the lungs.

The Respiratory System The trachea is a long tube that is also lined with cilia and mucus to filter air. The trachea branches to the lungs to form more tubes called bronchi. The bronchi branch even more to form bronchioles.

The Respiratory System At the end of the bronchioles, there are tiny air sacs called alveoli. The alveoli are only 1 cell thick and they are lined with capillaries. Gas exchange between the lungs and the blood occurs in the alveoli.

Prediction: What do you think occurs at the alveoli with carbon dioxide and oxygen?

The Respiratory System Oxygen moves into the blood and CO2 moves out of the blood at the alveoli through diffusion. Carbon dioxide is then removed from the body when we exhale.

What is the purpose of the reproductive system?

The Reproductive System The purpose of the reproductive system is to produce reproductive cells and offspring. Females also have the job of nurturing and protecting developing embryos.

What is the purpose of the circulatory system? List the organs found in the circulatory system.

The Circulatory System The function of the circulatory system is to transport materials. The blood is pumped by the heart. The heart pumps blood to the lungs, where it picks up oxygen and gets rid of carbon dioxide.

The Circulatory System Blood then returns to the heart, where it is pumped to the rest of the body., In addition to oxygen, the blood also carries nutrients, like glucose, amino acids, water, and hormones. Blood contains several types of cells.

The Circulatory System Red blood cells carry oxygen. White blood cells help to fight disease.

What is the purpose of the excretory (aka urinary) system? List the organs found in the excretory system. Define ex-: out of; away from

The excretory system eliminates wastes from the body. Wastes are the result from digestion and cell processes. The kidneys help to remove wastes from the blood.

The blood is filtered by the kidneys to remove waste products. The Excretory System The blood is filtered by the kidneys to remove waste products. The waste is then eliminated from the body as urine. The skin also helps to remove wastes through sweat. Lungs remove waste by eliminating CO2 from the body.

What is the purpose of the immune system? List the organs found in the immune system.

The immune system helps protect the body from diseases. White blood cells attack foreign organisms to prevent illness. The lymph nodes and spleen also aid in the immune system.

They filter fluid lost from blood vessels. The Immune System They filter fluid lost from blood vessels. They look for foreign organisms and other harmful substances. After the fluid is filtered, it is returned to the circulatory system.

What is the purpose of the muscular system? List the organs found in the muscular system.

The muscular system works with the skeleton to produce movement. The muscles also help to transport blood and move food through the digestive system.

What is the purpose of the skeletal system? List the organs found in the skeletal system.

The skeletal system supports the body and protects internal organs. The skeletal system also aids in movement and stores minerals, like Ca.

The skeleton also produces blood cells in the bone marrow. The Skeletal System The skeleton also produces blood cells in the bone marrow. The joints are were bones move, and they act like hinges.

What is the purpose of the nervous system? List the organs found in the nervous system.

The nervous system controls the body. It coordinates how the body responds to change, both inside and outside the body. The brain, spinal cord, and nerves make up the nervous system.

Without one, the others will not work. The Nervous System The brain’s decisions are carried to the body’s cells by nerves, also called neurons. Although the organ systems each have their own function, they all work together and depend on each other. Without one, the others will not work.

Homeostasis Notes

I can define homeostasis. I can explain how temperature is regulated in the human body. I can explain how blood sugar is regulated in the human body. I can explain how each body system helps to maintain homeostasis.

Prediction: What do you think homeostasis is?

Define homeo: similar to Define stasis: staying

Homeostasis Homeostasis is the process by which organisms maintain a stable internal environment. Homeostasis is required for life to continue and involves the help of several body systems.

What does your body do to maintain your body temperature? What happens when you get too hot? What happens when you get too cold?

Temperature For the body to maintain a constant temperature, there must be a balance between heat production and heat loss. The hypothalamus is found in the brain and acts like a human thermostat.

The hypothalamus is found in the brain. Temperature The hypothalamus is found in the brain. It monitors the temperature at the skin’s surface and the temperature of the organs at the body’s core. The core temperature is usually higher than the skin temperature.

Where does our body heat come from?

The normal internal body temperature should be 98.6 F or 37 C. If the temperature of the core decreases, the hypothalamus sends out a chemical signal to the body cells. The signal stimulates cells to speed up metabolism aka cell activities.

Cellular activities produce heat that increases body temperature. The increase in temperature is detected by nerve cells. This signals the hypothalamus to stop producing the chemicals that speed up cellular activities.

Shivering is the result of muscle contractions that also release heat. Temperature When the body is too cold, the hypothalamus will also release chemicals that cause the muscles to shiver. Shivering is the result of muscle contractions that also release heat.

What is more important to protect: your internal organs or your external organs (like fingers and toes). Predict what blood vessels do at the surface of your skin when you are cold.

Temperature When temperature is low, the blood vessels at the skin’s surface will close or constrict to conserve heat for your internal organs. If the body temperature increases too much, the hypothalamus will slow down cellular activities.

Why does sweating help cool the body? Predict what will happen to blood vessels at the surface of the skin when you are warm.

When body temperature increases, the body also sweats. Sweat helps cool the body by evaporation. When body temp is high, the blood vessels will also open, or dilate to release heat at the skin’s surface.

How is blood sugar regulated?

Insulin is a hormone produced by the pancreas. Blood Sugar Insulin is a hormone produced by the pancreas. Insulin helps to maintain the level of glucose in the blood. When blood glucose levels rise, the pancreas produces insulin.

These cells store the glucose as glycogen or fat. Blood Sugar Insulin stimulates liver and muscle cells to remove sugar from the blood. These cells store the glucose as glycogen or fat. When blood glucose is low, the pancreas secretes another hormone.

The hormone glucagon stimulates the release of glucose from the liver. Blood Sugar The hormone glucagon stimulates the release of glucose from the liver. The inability to maintain blood sugar levels results in diabetes.

Body Systems The nervous system maintains homeostasis by monitoring conditions inside and outside of the body and responding to changes. The digestive system helps maintain homeostasis by breaking down materials needed by the body.

The immune system keeps foreign organisms out. The circulatory system delivers essential nutrients and oxygen to body cells and carries wastes away. The respiratory system ensures cells have enough oxygen and removes carbon dioxide.

The excretory system makes sure that the body eliminates wastes and keeps the good stuff. Hormones also play a key role in maintaining homeostasis.

Cell Specialization Notes

I can define cell specialization/differentiation. I can explain what a stem cell is. I can explain how a cell becomes specialized.

How many cells did you start out as? What are stem cells?

Every cell in the human body developed from a single, fertilized cells. The cells that form after the first few divisions after fertilization can potentially become any type of cell.

A cell that is not specialized for a specific job is called a stem cell. Stem cells can potentially become any type of cell. All cells contain the exact same DNA, but each has a specific job.

Once a stem cell has been assigned a job, can it become a new type of cell?

When a cells is assigned a job, it becomes specialized. Another name for a specialized cell is a differentiated cell. During development and before birth, most cells become specialized.

Once a cell becomes a muscle cell, it will always be a muscle cell. Even though a muscle cell contains the same DNA as a heart cell, it cannot become a heart cell. Before a cell is differentiated, it can become any type of cell.

However, after a cell differentiates, it can no longer become any type of cell. Cell differentiation is the result of two things.

First, differentiation is the result of signals inside the cell by genetic control. Secondly, differentiation is the result of external influences in the cell’s environment.