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I just compiled everything I found concerning this assignment:
a. Starting with the clavicle bones, then from there we go into the shoulder bones known as the scapulas. After comes the upper arms which is made up of the humerus bone. Then to the lower arms which is broken down into the ulna and radius bones.The wrist comes next and is well known overall as the carpal bones which is broken down into several other bones known as hamate, pisiform, triquetral, lunate, trapezoid, trapezum, scaphold and the capitate. Then we move to the palm ofthe hand which is known as the metacarpals bones. Lastly we move into the fingers broken down into the phalanges, ditsals, middle and proximal bones. All the fingers were bent in some way, but the primary to fingers doing the work were the thumb which is broken down into distal phalanx, proximal phlanex and metacarpal bones. Both fingers were used in the process of holding the drawer knob.
b. The joints that are used in the upper extremities of this exercise are the following:
Shoulder joint which is the joint between the clavicle, humerus and scapula bones is known as the acromioclavicular joint. The action of this joint is extension. Next we have the proximal radioulnar joint which is at the top of the ulna and radius bones joining the humerus bone. It is also has an extension action. Lastly we have the distal radioulnar joint that joins the ulna and radius bones to the wrist bones. This is also has an action of extension. However, I believe that both flexion and extension were shown for each of these joints since they “extended” out to reach for the drawer but then flexion occurred once the drawer was being opened.
c. The primary muscles that were used in the following exercise while focusing on the upper extremities were the following: Starting with the shoulders, the deltoid,infraspinatus and the teres major muscles. Going to the arms starting from the top and working our way down, the triceps braachii, brachialis, brachioradilis, extensor carpi radialis jangus, extensor carpi ulnaris, extensor digitorum, and the flexor carpi radialis. Lastly we go to the hands which is made up of the thenar muscles.
d. When Jessie reaches for the cup, receptors, or nerve endings, detect a threat or an event that requires the body?39;s immediate attention which in this case is the hot cup. After the nerve endings have detected the heat from the cup, nerves, or neurons, carry the receptor?39;s information to the central nervous system or (CNS). The integration center in the CNS determines what Jessie’s body?39;s response will be. Then motor neurons carry the integrating center?39;s instruction to the appropriate part of Jessie’s body. An effector makes a necessary change to what?39;s going on in Jessie’s body causing him to jerk his hand away from the cup.
e. The reflex used is known as the crossed-extensor reflex. It is commonly described as the bodies reflex to pull away from hot or cold objects or when your body moves or jerks after feeling something sharp.
f. Vitamin C is believed to help gum disease because vitamin C is an antioxidant and is needed to repair connective tissue and accelerate bone regeneration.
g. After vitamin C is ingested, it is absorbed by the intestines using a sodium-ion dependent channel. It is transported through the intestine via both glucose-sensitive and glucose-insensitive mechanisms. The presence of large quantities of sugar either in the intestines or in the blood can slow absorption. As soon as it enters the blood, it becomes a water soluble antioxidant. Because it is in the water soluble state, vitamin C can directly affect the free radicals in the body. To excrete vitamin C. The excess Vitamin C is excreted by our body through urination. Vitamin C is excreted by glomerular filtration and is resorbed by the tubules. There is a maximum rate at which the tubules can reabsorb, so it is real economy to keep the urine alkaline.
h. Absorption and Bioavailability
Transport of vitamin C is a saturable and dose dependent process that occurs by active transport. At the intestine and cells AA is oxidized to DHAA, which is more quickly transported across the cell membrane. Once inside the tissue or intestinal epithelium the vitamin is reduced back to AA. | The degree of intestinal absorption decreases as intake of AA increases. Intakes of 1 to 1.5 grams results in 50% absorption, but at intakes over 12 grams only 16% of the vitamin is absorbed. In contrast, an intake of less than 20 mg, has a 98% absorption rate (13). Absorption of vitamin C is greater when several individual doses of vitamin C,in quantities less than one gram, are taken throughout the day rather than one megadose (17). Eighty to ninety-five percent of the vitamin C found in foods is absorbed (13). Furthermore, the bioavailability of synthetic and "natural" forms of the vitamin differ very little despite the claims made by manufacturers (13,17).Vitamin C absorption can be impaired by a number of factors. A single large dose saturates the enzyme kinetics for vitamin C, leading to excess AA in theintestinal lumen, which causes numerous gastrointestinal problems. Pectin and zinc also inhibit AA absorption, but this mechanism is not well understood. A high iron concentration in the gastrointestinal tract may cause oxidative destruction and in turn impair uptake (13).
Transport
Active transport is the main mechanism of vitamin C distribution within the body. Simple diffusion may occur in the mouth and stomach but accounts for only a very small percentage of uptake (13). Sodium-independent transport systems shuttle vitamin C across the basolateral membrane of the intestinal cells. In the plasma absorbed ascorbic and dehydroascorbate (DHAA) can either be transported freely or be bound to albumin. Ascorbate can also move into body cells and tissues (13). As previously mentioned DHAA is the primary form of vitamin C that crosses cellular membranes. The adrenal and pituitary glands, red blood cells, lymphocytes, and neutrophils all receive vitamin C in the form of DHAA (13,17).
Storage
Vitamin C is stored throughout body tissues and blood. Ascorbic acid content of blood components, fluid, and tissue varies widely on an individual basis. Tissue concentrations exceed those found in the plasma by three to ten times. Energy-driven transport pumps are responsible for the higher tissue concentrations ofvitamin C versus the plasma. Both tissue and plasma levels of vitamin C are correlated to intake up to 90 mg / day (13). The total body pool of vitamin C has been estimated, using radiolabeled isotopes, to a maximum of 20 mg/kg body weight. This corresponds to a plasma AA concentration of 57 umol/L. Alternate techniques ofmeasurement have estimated maximum total body AA stores to be 22 mg/kg (17). The pituitary glands, adrenal glands, and lens of the eye contain the highestvitamin C content (at least140umol/ 100 g wet weight) within the body (13,17). In contrast the saliva and plasma have the lowest AA content (17). Vitamin C content of cardiac tissue is between 28 and 85 ml/100g wet weight, while that in skeletal muscle is approximately 17 ml/100g wet weight (16). Other tissues withintermediate levels of vitamin C include the kidneys, brain, liver, lungs, and thyroid. The water-soluble properties of vitamin C prevent it from being stored in the adipose tissue of the body.
Excretion
The average half-life of AA is believed to be between 16 and 20 days (17). Its half-life is inversely related to intake. The water-soluble properties of vitamin C lead to urinary excretion of the vitamin. Metabolites of vitamin C including dehydroascorbate (DHAA), oxalic acid, 2-O-methyl ascorbate, and 2-ketoascorbitol are also excreted from the body via the urinary system (13,17). The kidneys play a major role in vitamin C excretion and retention. DHAA and AA can be reabsorbed by the kidney tubules as long as body pool levels are equal to or less than 1500 mg. Levels within the body that are 1500 mg or less will result in no urinary excretion ofvitamin C (13). As levels increase above 1500 mg the reabsorption efficiency of the kidneys decreases. Thus, body pool levels from 1500 to 3000 mg relate to tissue saturation of the vitamin (13). Plasma ascorbate levels between 0.8 and 1.4 mg/dl are considered the renal threshold. Above these levels, vitamin C will be excreted rather than reabsorbed by the kidneys (13).
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