An Introduction to A&P
- gtaylormsa
- Jul 23, 2015
- 4 min read
A&P is the shortened term I like to use to describe anatomy and physiology. The two are almost always referred to in a pair, because they share similarities as far as context and relationships. Strictly speaking, anatomy is the study of the body's structures, while physiology is the study of the body's functions. I went back to my online coursework at 3:45 PM that same day to continue study on the big ideas of physiology.
1. Living organisms are casual mechanisms with functions applicable to the laws of physics and chemistry.
2. The cell is the basic unit of life.
3. Life requires information flow between cells, and between the organism and its environment.
4. Matter and energy must be transformed and transferred to build an organism and perform work.
5. Homeostasis maintains the internal environment to be compatible with life.
6. The behavior of an organism can be understood through structure and function.
7. Organisms carry out functions at different levels of organization (more about that in a bit).
8. All life exists within an ecosystem.
9. Evolution explains the histroy of life on Earth.
As far as human physiology goes, our bodies perform several vital functions that we could not live without. Exchange with the environment happens through breathing and eating. Transport within the body occurs in the form of water and oxygen. Bones and muscles support structure and movement, and the brain handles control and regulation of the entire organism.
Levels of Organization
Elements --> molecules --> cells --> tissues --> organs --> organ systems --> organism
Next the courseware introduced me to body planes. The transverse plane divides the body into top and bottom horizontally. The coronal plane is a vertical plane which divides the body into front and back sections. The sagittal plane is a vertical plane which divides the body into left and right sections. Other terms used to pinpoint anatomical location include:
Superior or cephalic - towards the head; above
Inferior or caudal - towards the tail; below
Posterior or dorsal - towards the back
Anterior or ventral - towards the belly
Medial - towards the mid-sagittal plane, alone the coronal plane
Lateral - away from the mid-sagittal plane, along the coronal plane
Intermediate - between medial and lateral
Proximal - towards the core/origin of the body in extremities
Distal - away from the core/origin of the body in extremities
Superficial - towards the outside of the body; moving externally
Deep - away from the outside of the body; moving internally
After that I was introduced to systems. An organ system is an integrated collection of organs in the body that work together to perform a vital function. The major organ systems grouped by primary function are listed below:
Exchange with the environment
- Digestive system
- Respiratory system
Fluid transport within the body
- Cardiovascular system
- Lymphatic system (deals with immunity)
- Urinary system
Structure, support, protection, and movement
- Integumentary system
- Skeletal system
- Muscular system
Control and regulation
- Nervous system
- Endocrine system
The purpose of the digestive system, or gastrointestinal system, is to break down eaten material into nutrient molecules, absorb water and ions, and eliminate undigested residue. It is made up of a continuous tube called the digestive tract or alimentary canal. The mouth is where food is chewed and mixed with saliva to become bolus. The salivary glands produce saliva containing amylase, an enzyme which breaks down carbohydrates. The bolus then travels through the pharynx, a part of the throat, to the esophagus. In the stomach, chewed food is mixed with acids and enzymes to further break it down. The pancreas secrete a variety of enzymes as well as bicarbonate ions to neutralize stomach acids. The liver produces bile, which aids in fat digestion/absorption. The gall bladder stores and concentrates bile before secreting it into the small intestine. The small intestine then absorbs nutrients from broken down food and the large intestine absorbs water and minerals before feces are excreted through the anus.
The respiratory system allows the body to obtain oxygen needed for metabolic processes, and eliminate carbon dioxide to maintain pH homeostasis. Its organs include the nose and mouth, where air enters the body and is humidified and filtered, the pharynx (shared with the digestive system), the larynx, the trachea, and the lungs of course.
The cardiovascular system serves to transport nutrients, oxygen, ions, proteins, hormones, and other signaling molecules from one part of the body to another. The most plentiful organ of this system is blood, made up of plasma containing water, electolytes, glucose, proteins, and metabolic wastes, along with blood cells. Red blood cells transport oxygen and carbon dioxide. White blood cells fight infection. Platelets maintain hemostasis: our bodies' ability to stop bleeding after vascular injury. Other organs include the heart, arteries of the systemic circuit which travel from the heart to the rest of the body, and the pulmonary artery and veins which travel from the heart to the lungs.
I ended my research for the day at 5:30 PM.
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