|Life Science||Living Systems 7D3.00||Unifying Concepts of Science||Form and Function 2.2 a|
CONTENT STANDARD: Life Science
CONTENT TOPIC: Living Systems
CONCEPT: The human body is composed of different biological systems that are interrelated and dependent upon one another.
CONTENT OBJECTIVE: 7D3.00 To understand the structure and function of body systems and their inter-relationships
INSTRUCTIONAL OBJECTIVES: The learner will:
TN COMPONENT OF SCIENCE: Unifying Concepts of Science
BENCHMARK: Specialized structures perform specific functions.
The skeletal system and the muscular system work together to cause movement and locomotion. The purposes of the skeletal system are:
1. support and protect internal organs.
2. a place for muscles to attach for movement.
The joints in the skeletal system allow the system to bend and rotate. This use of joints allows free and quick movement. (Have students try to walk and sit without bending joints-IMPOSSIBLE!!)
Ligaments are tough tissues within the system that hold the bones to bones. The part of the skeleton that will give under pressure is called cartilage. (Have students push or bend nose and ears )
(Demonstrate - Use of bicycle air pump to show how a diaphragm pumps air in and out of lungs.)
(Have students draw and label the human respiratory system.)
The skin must be kept clean because bacteria live off of perspiration. If these bacteria are allowed to build up on the body they produce a waste known as body odor. The dirt and grime of skin can also add to the teenage problem of blackheads and acne.
The digestive system is the human body system that digests food into a soluble form. This form can be used by body cells as energy. The human body has a very "sophisticated" system developed to do this chemical process. Several organs that are not a part of the actual food tube contribute to the process. The formula for digestion is:
Food + H20 + Digestive Enzymes---> Soluble food + Enzymes
The enzymes involved in the digestion process are produced in glands. The salivary glands of the mouth start digestion. The glands lining the stomach secrete enzymes also, the pancreas and liver secrete enzymes into the stomach. The glands of the small intestine produce enzymes that help to finish the process. In the small intestines are thousands of villi that contain capillaries. Here is where soluble food diffuses out of villi into the blood stream. It then circulates to all body cells. Any undigested food collects in the large intestine, another excretory organ. The solid waste in the large intestine is eliminated from the body.
The nervous system is considered to be THE body controller. Actually this system work with the endocrine system to control and regulate body activities. The nervous system consists of several branches or systems working together for control.
The central nervous system is composed of the brain and the spinal cord. These two organs control the voluntary and involuntary actions of the body.
There are three parts to the brain. The cerebrum, which is the largest part of the brain. It controls things such as thinking, being aware, memory, learning, some voluntary movements and the five senses. The cerebrum is so well developed in humans that it causes man to be superior to all other animals. The cerebellum, maintains balance and muscle coordination . It is not as well developed in humans as in other animals.
The autonomic nervous system involves nerve cords on each side of the nervous system. This portion of the system regulates such involuntary actions as heartbeat, the release of hormones from glands and the action of smooth muscles in the digestive system.
The endocrine system is composed of ductless glands which produces hormones. These hormones are secreted directly into the blood streams and travel to all body parts. The main controller is a gland located in the base of the brain, the pituitary gland . It controls the other endocrine glands plus makes and secretes growth and reproductive glands. The thyroid gland is located in the throat. It regulates body metabolism. The parathyroid gland is located on the thyroid gland and regulates the calcium and phosphorus levels in the body.
The pancreas located in the abdomen contains cells called Islands of Langerhans that secrete the hormone insulin. This hormone regulates the level of sugar in the blood. Damage to these cells results in the disease called diabetes.
Circulation, or the circulatory system, is related to all of the other systems because this system is the body's way of getting materials to and from all body parts. This system works 24 hours a day throughout a person's lifetime.
The purposes of the circulatory system are to transport:
1. oxygen from lungs to cells
2. soluble food from small intestines to cells
3. carbon dioxide from cells to lungs
4. water from cell to kidney
5. hormones and antibodies to all cells
The heart is the pump for this system. It is composed of cardiac muscle. The path of blood through the heart is connected to the lungs where oxygen is picked up and carbon dioxide is released. The tubes carrying blood away from the heart to the body parts are called arteries. These arteries are connected to microscopic tubes called capillaries. These microscopic tubes come in direct contact with body cells where the exchange of materials occurs. The blood then travels back through veins to the heart to start the cycle again. As the blood flows through the various organs mentioned it either picks up or releases the products involved with each organ.
The blood is composed of plasma, the liquid part of the blood, and three main types of cells. Red blood cells are the largest and most numerous. They carry the oxygen picked up in the lungs and carry CO2 picked up from cells. The white blood cells are small and not as numerous as red blood cells. These are the cells that help fight off invaders (germs) that enter the body. The platelets are the blood cells that help blood clots form when an injury occurs. These platelets work with calcium, vitamin K and a protein called fibrinogen.
The types of helpful clots are scabs and bruises to stop the flow of blood. Some clots can do damage, such as those that cause heart attacks and strokes.
(Have students find their pulse. Do not use thumb, it is easy to find in the neck or temple. At their desk have students take pulse for 1 minute and write it down. Have students stand up and jog for one minute. When they are finished jogging, have them find and count their pulse again. Compare blood flow while resting and while exercising. Also, discuss the energy or calorie increase needed by the body during exercise.)
artery - blood vessel carrying blood away from the heart
autonomic nervous system - nerves associated with spinal nerves
capillaries - microscopic blood vessels that are in direct contact with body cells
cardiac muscle - muscle of the heart
cerebellum - part of brain for balance and muscle coordination
cerebrum- largest part of human brain
cranial nerves - nerves in face and head
ductless glands - glands that secrete their product directly into the blood stream
human anatomy - study of the structure of the body
joints - where two bones meet
ligaments - holds bone to bone at a joint
malfunction - does not function correctly
medulla - stem of the brain, controls many involuntary actions such as the secretion of glands, connects the brain to the spinal cord
metabolism - rate at which cells use food
ossification - process of depositing calcium around bone cells for strength
peripheral nerves - nerves connecting the spinal cord to body parts
perspiration - excretion from skin to cool the body, commonly called sweat
smooth muscle - involuntary in organs
soluble - form of food that is small enough to diffuse through a cell membrane
striated muscle - voluntary muscles
urea - waste filtered from the blood by the kidneys
urine - a combination of urea, water and salt filtered from the blood
veins - blood vessels that carry blood back toward the heart
villi - tiny finger-like projections in the walls of the small intestine
This is the time this file has been accessed since 04/02/98.
The University of Tennessee at Martin is not responsible for the information or views expressed here.
Seventh Grade Science Home Page