THE HUMAN BODY PLAN

IMPORTANT CONCEPTS 1. There are 4 types of tissues that make up the

human body 2. Tissues work together to make up an organ,

organs work together to make up an organ system 3. Each organ system has a specific function in

the body 4. All of the organ systems depend on each other

to maintain human body functions. 5. All animals need to maintain steady internal

conditions (homeostasis) to survive.

4 TYPES OF TISSUE

MUSCLE TISSUE Composed of cells that can contract in

a coordinated way Cardiac muscle in your heart and pumps blood Skeletal muscle moves your bones Smooth muscle in charge of functions you cannot control

(ex: food going through esophagus)

NERVOUS TISSUE Contains cells that receive and transmit

messages in the form of electrical impulses

Makes up brain, spinal cord, nerves

NEURONS

EPITHELIAL TISSUE

Contain cells that line or cover all internal and external body surfaces.

Cells are tightly bound together creating a protective barrier.

CONNECTIVE TISSUE

BLOOD

BONE

CARTILAGE

FAT TENDONS

• Binds, supports and protects structures in the body

ORGANIZATION

ORGAN SYSTEMS

http://www.proprofs.com/flashcards/tableview.php?title=mcb-organ-systems

BODY CAVITIES Each cavity contains 1 or more organs

BRAIN

SPINAL CORD

HEART, ESOPHAGUS, ORGANS OF RESPIRATORY SYSTEM

ORGANS OF DIGESTIVE SYSTEMORGANS OF REPRODUCTIVE AND EXCRETORY SYSTEMS

INTERDEPENDENCE Nutrients from the digestive system are

distributed by the circulatory system. Circulatory system depends on oxygen

from the respiratory system. Every system relies on the nervous

system to sense changes in the environment and respond accordingly.

EXAMPLE Each day, your body’s cells, tissues, and organs work together to keep you

responsive to the environment. Consider the example of eating your lunch. The lunch buzzer sounds just as your stomach is making some rumbling noises. Your brain records the information that the buzzer and time of the day mean you should eat. You proceed down the hall and enter the school cafeteria. In the cafeteria, your eyes see a poster advertising the daily specials, and your nose senses the odour of freshly made pizza. The message is sent to your brain, and you decide that you should eat pizza for lunch. While in the line, you decide to reach out and select a slice of pizza from the warming oven. The muscles in your hand and arm contract and relax, which enables you to pick up the slice of pizza without dropping it. Once in your seat, you chew and swallow a bite of pizza using your teeth and tongue (Figure 2.33). As the muscles in your digestive system push the food along, a variety of glands add juices to assist in breaking down the food into the necessary nutrients. In several hours, the nutrients in the pizza are absorbed into your bloodstream and carried through your body to the cells. In this example, several organ systems, including the circulatory, digestive, and nervous systems, interact to enable you to obtain, digest, and transport essential nutrients from the pizza to all cells of your body.

HOMEOSTASIS- KEEPING INTERNAL CONDITIONS STABLE

A specific responseamplifies until a properlevel is reached, and theresponse is stopped(designed to push levels out of normal ranges. )

The end point of a specific processregulates the beginning of that sameprocess. (maintain or regulate physiological functions )

HOMEOSTASIS- KEEPING INTERNAL CONDITIONS STABLE

Positive feedback loops

Negative feedback loops

During childbirth, pressure on mother’sUterus causes secretion of hormone oxytocin

This stimulates contractions, putting Pressure on the fetus

Pressure from the fetus further stimulatesThe hormone to be released.

Blood calcium must be at proper level formuscles to function.

If too low, parathyroid gland releases ahormone that pulls calcium from the bones and releases it into the bloodstream.

Once at proper level, the gland stopsreleasing the hormone.