INTRODUCTION TO PHYSIOLOGY AND HOMEOSTATIS
1.1 Intro to Physiology
Physiology: the study of the functions of living things, how the human body works Two approaches explain the events that occur in body
-purpose of the body process
- mechanism in which the process occurs
Physiologists view the body as a machine whose mechanisms of action can explained in terms of cause and effect sequences of physical and chemical processes. Physiology is closely related to anatomy: the study of the structure of the body. The nutrient –absorbing intestinal cells have a multitude of fingerlike projections in contact with the digested food. Based on knowledge of structure –function relationships, explain the functional advantage of this structural feature.
1.2 Levels of organization in the body
All matter is made up of atoms, the smallest building blocks of matter The most common atoms in the body are oxygen, carbon, hydrogen, and nitrogen, making up approximately 96% of the body. The atoms and a few others combine to form the molecules of life, such as proteins carbohydrates, fats and nucleic acids, even DNA
THE CELL: the fundamental unit of both structure and function in a living being is the smallest unit capable of carrying out the processes associated with life. Plasma Membrane: extremely thin, oily barrier that encloses the contents of a cell and controls movement of materials into and out of the cell -the cell’s interior contains a combination of atoms and molecules that differs from the mixture of chemicals in the environment surrounding the cell. Organisms: independent living things, simplest forms of independent life are single-celled organisms Multicellular organisms are more complex organisms, having many kinds of cells, such as muscle cells, nerve cells, and gland cells. During the development of multicellular organisms, each cell differentiates or becomes specialized to carry out a particular function; body is made up of about 200 specialized types of cells.
Basic Cell Functions
-obtaining food (nutrients) and oxygen from the surrounding environment. - performing chemical reactions that use nutrients and oxygen to provide energy - eliminating cells CO2 and wasters into the surrounding environment -synthesizing proteins and to her components needed for cell structure, for growth and carrying out functions -controlling the exchange of materials between the cell and environment -moving materials internally from one part of the cell to another, moving in there surrounding the environment. - sensitive and responsive to outside changes.
- reproducing, muscle and nerve cells lose the capability to reform after they are formed. Enzymes: specialized proteins that speed up a particular chemical reaction in the body
Tissues: formed of group cells of similar structure and specialized function consists of cells of a single specialized type, along with varying amount of extracellular material. Aggregate of various cellular and extracellular components that make up a particular organ. -Muscle Tissue: Contracting, generating tension and producing movement. There are three types:
-Skeletal: moves skeleton – Cardiac: pump blood in heart
- Smooth: controls movement of contents through hollow tubes and organs - Nervous tissue: Initiating and transmitting electrical impulses, sometimes over long distance. Electrical impulses act as signals that relay information throughout the body. (brain spinal cord, nerves) - Epithelial tissue: exchanging materials between the cell and its environment. Anything that enters or leave the body must go through epithelial barrier. Two general types: epithelial sheets, and secretory glands. Lumen: a cavity within a hollow organ or tube. The type and extent of controlled exchange vary depending on the location and function of the epithelial tissue. Glands: epithelial tissue derivatives specialized for secreting, formed by pockets in...
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