Chapter 1

Physiology

science that seeks to explain the physical and chemical mechanisms that are responsible for the origin, development, and progression of life.

Human Physiology

attempts to explain the specific characteristics and mechanisms of the human body that make it a living being.

pathophysiology

study of disordered body function and the basis for clinical medicine

cell

basic living unit of the body

microbiota

Communities of microorganisms that inhabit the body , can cause diseases, but most of the time they live in harmony with

50% to 70%

amount fluid in the adult human body

intracellular fluid

fluid inside the cells

extracellular fluid

fluid outside the cells

extracellular fluid

ions and nutrients needed by the cells to maintain life is in

extracellular fluid

internal environment of the body, or the milieu intérieur

extracellular fluid

contains large amounts of sodium, chloride, and bicarbonate ions plus nutrients for the cells, such as oxygen, glucose, fatty acids, and amino acids

intracellular fluid

contains large amounts of potassium, magnesium, and phosphate ions

homeostasis

maintenance of nearly constant conditions in the internal environment.

disease

often considered to be a state of disrupted homeostasis

transportation of extracellular fluid

1. movement of blood through the body in the blood vessels.

2. movement of fluid between the blood capillaries and the intercellular spaces between the tissue cells

rest

1 circuit

active

6 circuit

alveoli

where blood picks up oxygen in lungs

alveolar membrane

membrane between the alveoli and the lumen of the pulmonary capillaries

carbohydrates, fatty acids, and amino acids

different dissolved nutrients in gastrointestinal tract

liver

changes the chemical compositions of many of these substances to more usable forms, and other tissues of the body; eliminates certain waste products

Musculoskeletal System

provides motility for protection against adverse surroundings,

carbon dioxide

released from the blood into lung alveoli

kidneys

Passage of blood through the ___ removes most of the other substances from the plasma besides carbon dioxide

urea and uric acid

include excesses of ions and water from the food that accumulate in the extracellular fluid.

filter and reabsorb

function of kidneys

detoxification or removal of ingested drugs and chemicals

function of liver

sensory input, central nervous system, motor output

3 parts of nervous system

Sensory receptors

detect the state of the body and its surroundings

central nervous system

composed of the brain and spinal cord

autonomic system

operates at a subconscious level and controls many functions of internal organs, including the level of pumping activity by the heart, movements of the gastrointestinal tract, and secretion by many of the body’s glands.

endocrine glands

organs and tissues that secrete chemical substances called hormones

thyroid hormone

increases the rates of most chemical reactions in all cells, thus helping set the tempo of bodily activity.

Insulin

controls glucose metabolism

adrenocortical hormones

control sodium and potassium ions and protein metabolism

parathyroid hormone

controls bone calcium and phosphate

low oxygen, hemoglobin releases oxygen; high oxygen, hemoglobin will not release oxygen

oxygen-buffering function of hemoglobin; depends on hemoglobin

Carbon dioxide

major end product of oxidative reactions in cells

a higher than normal carbon dioxide concentration in the blood excites the respiratory center

causing a person to breathe rapidly and deeply

baroreceptor system

rapidly acting control mechanism of arterial blood pressure

decrease in co2 ecf concentration because the lungs expire greater amounts of co2 from the body

high concentration of carbon dioxide in the extracellular fluid increases pulmonary ventilation

can cause death

positive feedback leads to instability rather than stability

positive feedback

sometimes known as a “vicious cycle”

death

Extreme dysfunction leads to

sickness

moderate dysfunction leads to