Functions

Manufacture - blood proteins - albumen, clotting proteins , urea - nitrogenous waste from amino acid metabolism , bile - excretory for the bile pigments, emulsification of fats by bile salts

Storage - glycogen , iron - as hemosiderin and ferritin , fat soluble vitamins A, D, E, K

Detoxification -alcohol , drugs and medicines , environmental toxins

Protein metabolism -

• transamination - removing the amine from one amino acid and using it to produce a different amino acid. The body can produce all but the essential amino acids; these must be included in the diet.
• deamination - removal of the amine group in order to catabolize the remaining keto acid. The amine group enters the blood as urea which is excreted through the kidneys.

Glycemic Regulation - the management of blood glucose.

• glycogenesis - the conversion of glucose into glycogen.
• glycogenolysis - the breakdown of glycogen into glucose.

gluconeogenesis - the manufacture of glucose from non carbohydrate sources, mostly protein

Cardiac Control: The Cardiac Center in the medulla.

Outputs:

The cardioacceleratory center sends impulses through the sympathetic nervous system in the cardiac nerves. These fibers innervate the SA node and AV node and the ventricular myocardium. Effects on the SA and AV nodes are an increase in depolarization rate by reducing the resting membrane polarization. Effect on the myocardium is to increase contractility thus increasing force and therefore volume of contraction. Sympathetic stimulation increases both rate and volume of the heart.

The cardioinhibitory center sends impulses through the parasympathetic division, the vagus nerve, to the SA and AV nodes, but only sparingly to the atrial myocardium, and not at all to ventricular myocardium. Its effect is to slow the rate of depolarization by increasing the resting potential, i.e. hyperpolarization.

The parasympathetic division controls the heart at rest, keeping its rhythm slow and regular. This is referred to as normal vagal tone. Parasympathetic effects are inhibited and the sympathetic division exerts its effects during stress, i.e. exercise, emotions, "fight or flight" response, and temperature.

Inputs to the Cardiac Center:

Baroreceptors in the aortic and carotid sinuses. The baroreceptor reflex is responsible for the moment to moment maintenance of normal blood pressure.

Higher brain (hypothalamus): stimulates the center in response to exercise, emotions, "fight or flight", temperature.

Intrinsic Controls of the Heart:

Right Heart Reflex - Pressoreceptors (stretch receptors) in the right atrium respond to stretch due to increased venous return. The reflex acts through a short neural circuit to stimulate the sympathetic nervous system resulting in increased rate and force of contraction. This regulates output to input

The Frank-Starling Law - (Starling's Law of the Heart) - Like skeletal muscle the myocardium has a length tension curve which results in an optimum level of stretch producing the maximum force of contraction. A healthy heart normally operates at a stretch less than this optimum level and when exercise causes increased venous return and increased stretch of the myocardium, the result is increased force of contraction to automatically pump the increased volume out of the heart. I.e. the heart automatically compensates its output to its input.

An important relationship in cardiac output is this one:

Blood Flow =  D Pressure / Resistance to Blood Flow      

1) Storage - the stomach allows a meal to be consumed and the materials released incrementally into the duodenum for digestion. It may take up to four hours for food from a complete meal to clear the stomach. 
2) Chemical digestion - pepsin begins the process of protein digestion cleaving large polypeptides into shorter chains . 
3) Mechanical digestion - the churning action of the muscularis causes liquefaction and mixing of the contents to produce acid chyme. 
4) Some absorption - water, electrolytes, monosaccharides, and fat soluble molecules including alcohol are all absorbed in the stomach to some degree.

Cells, cytoplasm, and organelles:

• Cytoplasm consists of a gelatinous solution and contains microtubules (which serve as a cell's cytoskeleton) and organelles

• Cells also contain a nucleus within which is found DNA (deoxyribonucleic acid) in the form of chromosomes plus nucleoli (within which ribosomes are formed)

• Organelles include:

1. Endoplasmic reticulum : 2 forms: smooth and rough; the surface of rough ER is coated with ribosomes; the surface of smooth ER is not , Functions include: mechanical support, synthesis (especially proteins by rough ER), and transport
2. Golgi complex consists of a series of flattened sacs (or cisternae) functions include: synthesis (of substances likes phospholipids), packaging of materials for transport (in vesicles), and production of lysosomes
3. Lysosome : membrane-enclosed spheres that contain powerful digestive enzymes , functions include destruction of damaged cells & digestion of phagocytosed materials
4.  Mitochondria : have double-membrane: outer membrane & highly convoluted inner membrane
   1. inner membrane has folds or shelf-like structures called cristae that contain elementary particles; these particles contain enzymes important in ATP production
   2. primary function is production of adenosine triphosphate (ATP)
5. Ribosome-:composed of rRNA (ribosomal RNA) & protein , primary function is to produce proteins
6. Centrioles :paired cylindrical structures located near the nucleas , play an important role in cell division
7. Flagella & cilia - hair-like projections from some human cells
   1. cilia are relatively short & numerous (e.g., those lining trachea)
   2. a flagellum is relatively long and there's typically just one (e.g., sperm)

• • Villi  Projections of cell membrane that serve to increase surface area of a cell (which is important, for example, for cells that line the intestine)

The defecation reflex:

As a result of the mass movements, pressure is exerted on the rectum and on the internal anal sphincter, which is smooth muscle, resulting in its involuntary relaxation. Afferent impulses are sent to the brain indicating the need to defecate. The external sphincter is voluntary muscle and is controlled by the voluntary nervous system. This sphincter is relaxed along with contraction of the rectal and abdominal muscles in the defecation reflex

Basic Properties of Gases

A.    Dalton's Law of Partial Pressures

1.    partial pressure - the "part" of the total air pressure caused by one component of a gas 

     Gas            Percent            Partial Pressure (P)
    ALL AIR        100.0%                760 mm Hg
    Nitrogen       78.6%                   597 mm Hg    (0.79 X 760)
    Oxygen          20.9%                l59 mm Hg    (0.21 X 760)
    CO₂              0.04%                  0.3 mm Hg    (0.0004 X 760) 

2.    altitude - air pressure @ 10,000 ft = 563 mm Hg
3.    scuba diving - air pressure @ 100 ft = 3000 mm Hg

B.    Henry's Law of Gas Diffusion into Liquid

1.    Henry's Law - a certain gas will diffuse INTO or OUT OF a liquid down its concentration gradient in proportion to its partial pressure

2.    solubility - the ease with which a certain gas will "dissolve" into a liquid (like blood plasma)

HIGHest solubility in plasma            Carbon Dioxide
                                                      Oxygen
                                        
LOWest solubility in plasma             Nitrogen

C.    Hyperbaric (Above normal pressure) Conditions

1.    Creates HIGH gradient for gas entry into the body

2.    therapeutic - oxygen forced into blood during: carbon monoxide poisoning, circulatory shock, asphyxiation, gangrene, tetanus, etc.

3.    harmful - SCUBA divers may suffer the "bends" when they rise too quickly and Nitrogen gas "comes out of solution" and forms bubbles in the blood