Physiology Chapter 1 PDF

**Physiology** -- science that explains the physical and chemical mechanisms that are responsible for the origin, development, and progression of life. **Human Physiology** -- explains the specific characteristics and mechanisms of the human body that make it a living being **Pathophysiology** --...

**Physiology** -- science that explains the physical and chemical mechanisms that are responsible for the origin, development, and progression of life. **Human Physiology** -- explains the specific characteristics and mechanisms of the human body that make it a living being **Pathophysiology** -- study of disordered body function and the basis of clinical medicine **CELLS ARE THE LVINING UNITS OF THE BODY** **Cell** -- the basic unit of life **Similar Characteristics of a Cell** - Utilize O^2^ and marcomolecules - Mechanism of energy production - By products of chemical reactions are delivered to the surrounding fluid - Ability to reproduce ***Microorganisms living in the body outnumber human cells*** - **Microbiota** -- communities of microorganisms *50% - 70% of the adult human body is made up if fluid* **Intracellular fluid** -- fluid INSIDE the cell - Found in the cytoplasm, vacuoles - 2/3 of the fluid - contains **POTASSIUM**, magnesium, phosphates **Extracellular fluid** -- fluid OUTSIDE the cell - In the blood plasma inside blood vessels - 1/3 of the fluid - Contains **SODIUM**, chloride, bicarbonate - Considered as the "internal environment" - Carries waste products -- carbon dioxide and metabolic waste **HOMEOSTASIS** -- maintenance of nearly constant conditions in the internal environment. - All organs/tissues perform functions to maintain homeostasis - Levels of ions nutrients or wastes are regulated within a narrow range - Powerful control systems maintain concentrations of substances at levels that allow normal body function despite wide variations affected by the environmental changed, injury & disease - Trade-offs are necessary but can cause abnormalities in the long run 1. Intravascular -- movement of blood within vessels 2. Intracellular -- movement between blood cells **THE DISSOLVED NUTRIENTS & THEIR ORIGIN** 1. Oxygen -- Respiratory system 2. Macromolecules (carbohydrates, fatty acids, amino acids) -- obtained from food; Gastrointestinal System **REMOVAL OF METOBOLIC END PRODUCTS** 1. Lungs -- removes CO^2^ in exchange for O^2^; done through exhaled air 2. Kidneys -- filters blood; removes waste through urine 3. Gastrointestinal system -- eliminates undigested food via feces 4. Liver -- detoxifies ingested drugs & chemicals; secretes additional waste through bile **REGULATION OF BODY FUNCTIONS** 1. Nervous System - Sensory System -- includes sensory organs & receptors which detect the state of the body & surroundings - Central nervous system -- includes the brain & spinal cord; stores information & determines how the body responds - Motor system -- includes nerves that control the muscle and reflexes; responsible of execution of plans & responses to stimuli - Autonomic system -- includes the sympathetic & parasynthetic systems; subconscious control of the functions of internal organs 2. Endocrine System - Secretes hormones that are transported via blood to other organs **SYSTEMS FOR PROTECTION OF THE BODY** 1. Immune Systems -- Includes spleen, thymus, lymph nodes & white blood cells Highly-specialized mode of protection: a. Able to identify harmful cells b. Destroy foreign invaders through cell-mediated killing or antibodies 2. Integumentary System -- includes the skin & appendages c. Cover, cushion & protect deep tissue & organs d. Boundary between inside and outside of the cell e. Temperature regulation & excretion of wastes f. Sensory receptors 3. Reproductive System g. Generates new beings in place for those who have died **CONTROL SYSTEMS OF THE BODY** - Genetic control systems regulate intracellular & extracellular functions - Organs regulate their own functions or control interrelationships between organs **Regulation of Oxygen Levels** - Hemoglobin combines with oxygen in the lungs & travels to different organs - If O^2^ is low -\> O is released - If O^2^ is adequate -\> Hgb does not let go of O^2^ **Regulation of Carbon Dioxide Levels** - Co^2^ is the major end product of cell metabolism - Harmful if high levels - If CO^2^ is high -\> rapid breathing - Deep and rapid breathing releases & removes the excess CO^2^ **REGULATION OF ARTERIAL BLOOD PRESSURE** 1. Baroreceptor system -- Pressure detector system 2. Vasomotor System -- reduces heart rate and relaxes blood vessel well If high BP, Up stretch of baroreceptors \--\> vasomotor center becomes stimulated = Lower pumping of the heart + relaxation of vessel wall \--\> BP lowers back to normal If low BP, down stretch of baroreceptors \--\> vasomotor center is not stimulated = increase pumping of the heart + constriction of vessel wall \--\> BP increases back to normal **FEEDBACK CONTROL SYSTEM** 1. Negative Feedback -- refers to the inhibition of a process in the presence of excessive by product 2. Positive Feedback -- stimulation process in the presence of deficiency a. Considered a vicious cycle that leads to further harm & possible death 3. Feed forward control (Adaptive control) -- delayed negative feedback; tells the brain if a movement is done correctly - Age - Sex - Race/ Ethnicity - Lifestyle - Hormones