Anatomy and Physiology

Anatomy and physiology

The five structural levels of organization in the body are as follows:

1. Cells are the smallest living units in our body, yet they are very complex.

2. Tissues are more complex than cells. Tissues are an organization of many cells that act together to perform a function. The cells are held together and surrounded with nonliving, glue-like intercellular substances.

3. Organs are more complex than tissues. An organ can have several kinds of tissue that works together as a unit, to perform a special function.

4. Systems are the most complex units in our body. A system is an organization of varying numbers and kinds of organs arranged so they can work together to perform complex functions of the body.

5. The body as a whole is the atoms, cells, tissues, organs, and systems. The body is a unified complex structure that works together to make the body function.

77. The five main parts of a cell are listed below.

1.Cytoplasm is a specialized living material made of cells. Cytoplasm is in between the plasma membrane and the nucleus. As a group, these structures, made up most of the cytoplasm, are called organelles.

2.The plasma membrane is a membrane that encloses the cytoplasm and forms the outer layer of the cell. It is quite small at 3/10,000,000 of an inch. It has an orderly structure.

3.Interstitial fluid is located in the spaces in between the cells. It bathes the cells in every part of the body.

4.Organelles are specialized structures and are contained within the cytoplasm of each cell. They are described are little organs, because they function like organs function in the body.

5.The nucleus is double-membraned, spherical, and envelops the DNA strands. It controls protein synthesis, playing an important role in other cells activities such as active transport, metabolism, growth and heredity.




The eleven major organ systems in the body are listed below, along with a description of each systems main function.

The Integumentary system’s main functions include protection, regulation of body temperature, synthesis of chemicals, and sense organs.

The Skeletal system’s main functions include support, movement (with joints and muscles), storage of minerals, and blood cell formation.

The Muscular system helps with movement, maintenance of body posture, and production of heat.

The Nervous system’s main functions are to help with communication, integration, control (control is fast and short), and recognition of sensory stimuli.

The Endocrine system’s main function is the secretion of hormones directly into the blood, which helps with communication, integration, and control. However, control is slow and long in duration.

The Cardiovascular system is responsible for transportation, regulation of body temperature, and immunity.

The Lymphatic system is responsible for transportation, and immunity.

The Respiratory system’s main functions include the exchange of waste gas for oxygen in the lungs and the filtration of irritants from inspired air. It also regulates acid-based balance.

The Digestive system is responsible for the mechanical and chemical breakdown of food. It absorbs nutrients, and eliminates waste products.

The Urinary system has the function of cleaning the blood of waste products. It helps with electrolyte balance and acid-base balance.

11.The Reproductive system has the function of producing sex cells, transfer and fertilization of sex cells, development and birth of offspring, and nourishment of offspring. This will encourage the survival of species.






The two divisions of the human skeleton are described below.

The Axial skeleton is the bones that make up the center of the body. This includes the skull, spine, and chest.

The appendicular skeleton consists of the bones of the upper and lower extremities.

80. a. the function of the autonomic nervous system is to regulate parts of the nervous system that are involuntary functions.

b. The two divisions of the autonomic system are the sympathetic nervous system and the parasympathetic nervous system. The function of the sympathetic nervous system is that it works as an emergency system. It works automatically mainly for survival. The parasympathetic nervous system functions to dominate control of many visceral effects under normal, everyday conditions.

c. The fight of flight syndrome is the changes produced by increased sympathetic impulses allowing the body to deal with any type of stress.