Organization of the body

 

 

 

 

Anatomy and physiology is the study of the human body. They are closely connected in that the structure of an organ suits its function.

á      Anatomy is concerned with the structure of a part. 

á      Physiology is concerned with the function of the part.

The structure of the body can be studied at different levels of organization. All substances are composed of chemicals made up of submicroscopic particles called atoms. Atoms join to form molecules, which can in turn join to form macromolecules. Macromolecules are found in call fells, the basic units of all living things.  Within cells are organelles, tiny structures that perform cellular functions. A tissue is composed of similar types of cells and performs a specific function. An organ is composed of several types of tissues and performs a particular function within an organ system.  All of the body systems together make up the organism- such as a human being.

 

 

Anatomical Terms

There are various terms used to describe the location and region of the body that an organ is in.  These terms refer to the body when it is in the anatomical position. The anatomical position is standing erect, with face forward, arms at the side, and palms and toes directed forward.

á      The terms superior/inferior are above/below another body part.

á      Anterior/posterior are toward the front of the body or the back of the body.

á      Medial/lateral are nearer to the middle or farther away from the middle.

á      Proximal/distal are closer to the point of attachment or farther away.

á      Superficial/deep are located nearer the surface or farther away.

 

 

Planes of the Body

There are three planes in our body.  A plane is an imaginary flat surface passing through the body.

 

 

 

 

 

 

 

Sagittal plane- extends lengthwise and divides the body into right and left positions.

Transverse plane- perpendicular to the bodyÕs long axis and therefore divides the body horizontally to produce a cross section.

Frontal plane- extends lengthwise and divides the body into anterior and posterior planes.

 

 

Quadrants of the Body

There are four abdominal quadrants and they are:

 

 

 

 

Systems of the Body

There are 11 major systems of the body.

Integumentary System: protects the body from infection and loss of water.  The main part of this system is skin.

 

Nervous System: this system helps us to respond to outside environments. The main organs of this system are the brain and the spinal cord.

 

Circulatory System: carries blood throughout the body. The main organ of the circulatory system is the heart.

 

Endocrine System: secretes chemicals that serve as messengers between body parts. The main part of this system is hormonal glands.

 

Skeletal System: protects body parts.  The skull is the main part of the skeletal system.

 

Lymphatic System: protects the body from disease.  One of the main parts of this system is the spleen.

 

Muscular System: gives us the ability to move.  A major part of the muscular system is biceps.

 

Respiratory System: brings oxygen to the lungs and take carbon dioxide out.  A main organ in this system is the lung.

 

Digestive System: breaks down foods.  The main organs of the digestive system are the intestines.

 

Urinary System: gets rid of wastes.  The bladder is the main organ of this system.

 

Reproductive System: gives us the ability to reproduce.  Testes and ovaries are the main organs of this system.

 

 

 

Homeostasis

Homeostasis is the relative consistency of the bodyÕs internal environment.  Body temperature and blood flow are examples of this.

 

 

Negative Feedback

Keeps a variable close to a particular value or set point.

 

Disease

When homeostasis fails and the body no longer functions properly.

 

Local vs. Systemic: 

Local is restricted to a specific part of the body and systemic affects the entire body or involves certain organ systems.

 

Acute vs. Chronic:

Acute occurs suddenly and usually lasts a short time, chronic is less severe, develops slow, and is long term.

 

 

 

Organ Transplants

There have been two major breakthroughs that have allowed doctors to organ transplants. One is they have made solutions to preserve donor organs for several hours. Another is immunosuppressive drugs so your body doesnÕt reject the organs.