Part 1 The Cell and the Cellular Environment

Transcription

1 1 Chapter 3 Anatomy and Physiology Part 1 The Cell and the Cellular Environment 2 The Human Cell The is the fundamental unit of the human body. Cells contain all the necessary for life functions. 3 Cell Structure The cell membrane is the outer covering that encircles and protects the cell. It is semipermeable. is the thick, viscous fluid that fills and gives shape to the cell. are structures that perform specific functions within a cell. 4 Organelles : Contains the DNA Endoplasmic reticulum: synthesis functions Golgi apparatus: synthesis and secretion functions : energy factories Lysosomes: contains digestive enzymes : neutralize toxins 5 The Normal Cell 6 Cell Function All human cells have the same general structure and material. Differentiation causes cells to become. There are major functions of cells. 7 Major Functions of Cells (muscle cells) Conductivity (nerve cells) Metabolic absorption (intestines and kidneys) (produces hormones, mucus, sweat, saliva) Excretion (all cells break down nutrients) Respiration (take in oxygen) (enlarge, divide, and reproduce themselves) 8 Tissues Tissue refers to a of cells that perform a similar function. 9 Tissue Types 1

2 10 Epithelial Tissue Lines internal and body surfaces and protects the body. Some forms perform specialized functions: -Secretion -Absorption - -Filtration, mucous membranes, lining of intestinal tract. 11 Muscle Tissue Has the capability of contraction when stimulated. Muscle Muscle Muscle 12 Connective Tissue Most tissue in the body. Provides support, connection, and insulation. Examples include, cartilage, and fat. is classified as connective tissue. 13 Nerve Tissue Specialized tissue that transmits impulses throughout the body. Examples include the, spinal cord, and peripheral nerves. 14 Organs, Organ Systems, and the Organism An organ is a group of functioning together. A group of organs working together is an organ. The sum of all cells, tissues, organs, and organ systems makes up an organism. 15 Organ Systems 1 Cardiovascular Gastrointestinal Genitourinary Reproductive 2 Endocrine Muscular 2

3 16 System Integration 17 Homeostasis Homeostasis is the term for the body s natural tendency to keep the internal environment and metabolism and normal. A significant amount of is required to maintain the anatomy and physiology of the body. 18 Metabolism Metabolism is the term used to refer to the building up ( ) and breaking down ( ) of biochemical substances to produce energy. 19 The body s cells interact and intercommunicate with substances secreted by various body. If these messages are interrupted, a disease can develop or advance 20 Endocrine Glands Sometimes called glands. Secrete directly into the circulatory system. Some endocrine glands include: pituitary,, parathyroid, adrenal glands, Islets of Langerhans in the pancreas, testes, and ovaries. 21 Exocrine Glands 22 Water Secrete substances such as, saliva, tears, mucus,and digestive juices onto the epithelial surfaces via ducts. 23 Total Body Water (TBW) Water is the most substance in the human body Total Body Water (TBW): The total amount of water in the body at a given time. Average adult weighing 70kg, TBW is about liters (11 gallons) 24 Fluids Intracellular fluid (ICF): the fluid the cells Extracellular fluid (ECF): the fluid the body cells 25 Extracellular Fluid Two types of ECF: fluid: fluid within the circulatory system (blood plasma) fluid: fluid within body tissues that is outside the cells and outside the vascular system Synovial fluid, aqueous humor, secretions such as saliva, tears, etc. 3

4 26 Body Fluid Compartments Intracellular fluids make up % of total body water Liters in a 70kg person Extracellular fluid make up % of total body water 10.5 Liters in a 70kg person Interstitial fluids % of TBW Intravascular fluids % of TBW 27 Dehydration The body requires a proper balance of input and % to function properly Dehydration is an abnormal % in body fluids 28 Causes of Dehydration losses vomiting, diarrhea Increased loss: through normal mechanisms sweat, water vapor from lungs, saliva Increased 29 Causes of Dehydration losses (3 rd space): losses into fluid compartments peritonitus, pancreatitis, bowel obstruction losses burns, surgical drains, open wounds 30 S/S of Dehydration Dry mucous membranes Poor skin Excessive If severe, S/S of hypovolemic shock Treatment is fluid replacement Positive Test 10% increase in rate OR 10% decrease in BP between lying and sitting 31 Overhydration Overhydration is the presence of an abnormally high amount of body May indicate presence of heart Treatment is of excess fluids 32 Electrolytes 33 Electrolytes Substances that, in water, separate into electrically particles called ions : charged particles 4

5 34 Cations have a positive charge. have a negative charge. 35 Sodium (Na + ) Most prevalent cation in fluid. follows sodium. Important in transmission of nervous impulses. Hypernatremia is an abnormal increase in sodium. is an abnormal decrease in sodium. 36 Potassium (K + ) Most prevalent cation in the fluid. Important in transmission of electrical impulses. is an abnormally high potassium level. Hypokalemia is an abnormally potassium level. 37 Calcium (Ca ++ ) Plays a major role in contraction as well as nervous impulse transmission. Hypercalcemia is an abnormally increased calcium level. is an abnormally low calcium level. 38 Magnesium (Mg ++ ) 39 Anions Necessary for several biochemical processes. Closely associated with. is an abnormally increased level of magnesium. Hypomagnesemia is an abnormally decreased level of magnesium. 40 Chloride (Cl - ) charge balances the positive charge of cations. Major role in fluid balance and function. Associated with. 41 Bicarbonate (HCO 3 - ) Principle of the body. Buffer: preserves or restores normal acid-base Neutralizes the ion and other organic acids. 42 Phosphate (HPO 4 - ) Important in body storage Closely associated with magnesium in 5

6 function. Acts as a, primarily in the intracellular space. 43 Osmosis and Diffusion 44 Osmosis Osmosis is the passage of a solvent through a membrane; movement of solvent in a solution from an area of solute concentration to an area of concentration : a liquid substance that is capable of dissolving other substance : a dissolved substance 45 Osmosis 46 Diffusion Diffusion the movement of molecules through a semipermeable membrane from an area of concentration to an area of concentration Usually an Requires no energy 47 Diffusion 48 Types of Solutions (1 of 2) solutions on opposite sides of a membrane are equal in concentration. Results in fluid shift LR, NS the concentration of a given solute is greater on one side of a membrane than the other. Results in of fluids D50W, D25W 49 Types of Solutions (2 of 2) the concentration of a given solute is less on one side of a membrane than the other. Fluid will to a higher concentration D5W 50 Active Transport The movement of a substance across the cell membrane against the osmotic (toward the side that already has more of the substance). Opposite to the normal direction of diffusion Faster than diffusion. Requires. 51 Facilitated Diffusion 6

7 Certain molecules can move across the cell membrane with the assistance of helper. is one example. Depending on the substance, this movement may or may not require. 52 Osmotic vs. Oncotic Osmotic pressure exerted by the concentration of solutes on one side of a semipermeable membrane. force (colloid osmotic pressure): osmotic pressure exerted by large protein particles (colloids) 53 Acid-Base Balance 54 Acid-Base Balance Acid-base balance is a dynamic relationship that reflects the relative concentration of ions in the body. Hydrogen ions are acidic and the concentration of those in the body must be maintained within fairly strict limits. Any adversely affects the body Changes from to second 55 The ph Scale ph=potential of The ph scale is inversely related to hydrogen ion concentration The greater the hydrogen concentration, the lower the ph The ph scale ranges from to Normal body ph is to ph below 7.35= ph above 7.45= Variance of can be lethal 56 Regulation of Acid-Base Balance The body is constantly producing hydrogen ions (acids) through and other biochemical processes To maintain the correct acid-base balance, these hydrogen ions must be 57 3 Mechanisms to Remove Hydrogen system (bicarbonate buffer system) function 58 Buffer System (Bicarbonate Buffer System) The mechanism. Two components of this system are bicarbonate ion (HCO 3 - ) and carbonic (H 2 CO 3 ) and are normally in equilibrium with hydrogen (H + ). 7

8 59 H + + HCO 3 - H 2 CO 3 Hydrogen may combine with to produce carbonic acid. In other circumstances carbonic acid will into bicarbonate and hydrogen. Normally, for every molecule of carbonic acid, there are molecules of bicarbonate ion. (Ratio of 20:1) 60 H + + HCO 3 - H 2 CO 3 An increase in hydrogen ion ( ) is corrected as the excess hydrogen ions combine with bicarbonate ions to form carbonic acid Increase in hydrogen ion leads to an increase in acid A decrease in hydrogen ions ( ) will cause carbonic acid to dissociate into bicarbonate ion and hydrogen ion 61 H + + HCO 3 - H 2 CO 3 Acid: H + + HCO 3 - H 2 CO 3 Acid: H + + HCO 3 - H 2 CO 3 62 Acid-base Relations Relevant to ph 63 Respiratory and Kidney Mechanisms Increased respirations cause increased elimination of which causes a decrease in hydrogen ions and an increase in ph. The kidneys regulate the ph by altering the concentration of ions in the blood. 64 Acid Base Balance Disorders Respiratory Respiratory Metabolic Metabolic 65 The Respiratory Component of Acid-Base Balance Decreased ventilations lead to PaCO 2 and carbonic acid which lowers the ph ventilations = PaCO 2 + H 2 CO 3 = Respiratory Increased ventilations lead to PaCO 2 and carbonic acid which increases the ph ventilations = PaCO 2 + H 2 CO 3 = Respiratory 66 The Respiratory Component of Acid-Base Balance 67 Respiratory Acidosis CO 2 + H 2 0 H 2 CO 3 H + + HCO 3 8

9 Simplified: CO 2 H + As CO 2, ph should decrease producing acidosis Commonly seen on patients in respiratory or breathing very slowly 68 Respiratory Alkalosis CO 2 + H 2 0 H 2 CO 3 H + + HCO 3 Simplified: CO 2 H + As CO 2 decreases, ph should producing alkalosis Caused by 69 Normal Values ph: to PaCO 2 : to torr PO 2 : to torr 70 Abnormal Values Respiratory : ph and CO 2 Respiratory : ph and CO 2 71 Example: ph = 7.25 PaCO 2 = 60 What is the acid/base imbalance? 72 Example: A patient is found unconscious and breathing 6 times per minute Should the PaCO 2 be high or low? Should the ph be high or low? What is the respiratory ph imbalance? 73 Example: A patient is found hyperventilating and breathing 46 times per minute Should the PaCO 2 be high or low? Should the ph be high or low? What is the respiratory ph imbalance? 9

10 74 Example: ph = 7.60 PaCO 2 = 20 What is the acid/base imbalance? 75 Simplifying Acid/Base Imbalances Look at the ph If it is below 7.35 then it is If it is above 7.45 then it is Look at the PaCO 2 If it is below torr or above torr, then it is respiratory If the PaCO 2 is within torr, then the imbalance is 76 Simplifying Acid/Base Imbalances There can be combination of metabolic and respiratory Respiratory problems will normally affect changes Metabolic problems will normally affect changes Metabolic imbalances will be discussed later 10