B::الموضوع::أحتاج لمساعدة عاج " href="http://love.datingnakedfemales.com/feed//en/meetings.php" /> Love Datingnakedfemales En Meetings Php Dating Naked Females i<img src="http://www.famous-people-nude.com/babylonxx/aubrey-oday/aubrey-oday_09.jpg"/>B::الموضو<img src="http://shop.ehobbyasia.com/media/catalog/product/cache/1/image/5e06319eda06f020e43594a9c230972d/a/-/a-ch-01-ln-b_1_mark.jpg"/>ع:<img src="http://www.damplips.com/wp-content/uploads/2008/02/naked-woman-04.jpg"/>:أحتاج لمساعدة عا<img src="http://www.chrugirls.com/xxx/naked8/naked_teen%20(113).jpg"/>ج<img src="http://media.dailycamera.com/bdc/content/img/photos/2008/10/31/N1101NAKED1_t600.JPG"/>

Naked Dating Naked

Love Datingnakedfemales En Meetings Php Dating Naked Females iB::الموضوع::أحتاج لمساعدة عاج

Love Datingnakedfemales En Meetings Php Dating Naked Females

ide.  In mammals, air enters the body through the external nares and enters the nasal cavities dorsal to the hard palate. As air passes through these convoluted cavities, it is humidified and warmed to body temperature and dust is caught in the mucus of the membranes that line the cavities.  Air moves from here into the nasopharynx, where it passes through the glottis into the larynx.  Carefully cut the soft palate longitudinally to examine the nasopharynx of your specimen.
The larynx is a hard-walled chamber composed of cartilaginous tissue.  In the course of hominid evolution, the larynx has moved downward (caudally).  As a result, human vocalizations tend to come out of the mouth, where the tongue can manipulate them.  In chimps, the larynx is higher in the throat, with the result that vocalizations are very nasal (and thus less controllable and understandable).  Our descended larynx comes with a price – it makes choking on food far more likely.  Interestingly, human babies retain an elevated larynx.  It makes baby talk difficult, but it also allows babies to nurse and breathe at the same time.
Slit the larynx longitudinally to expose the vocal cords.  The vocal cords are elastic ridges that stretch across the space within the larynx.  When air passes over the vocal cords during exhalation, the cords vibrate and produce sound. In adult humans, laryngitis results from viral infection of the vocal cords.  They swell and regular speech is difficult to impossible.  
Read the following information about the respiratory system.  However, do not attempt to identify structures other than the trachea until you have exposed the heart and its major vessels (see Circulatory System further below).
           The trachea, distinguished by its cartilaginous rings (incomplete on the dorsal side), divides into the two bronchi (singular bronchus), which enter the lungs and divide into bronchioles (don’t try to find the bronchi until you’ve finished examining the heart and its major vessels).  Bronchioles terminate in alveoli, where gas exchange takes place.
           The right lung typically consists of four lobes and the left of two or three.  How many does your pig have?  The lungs in your fetal pig are small and fairly solid because they have never been inflated.  Inflation causes lungs to have a spongy appearance.  Note the position of the diaphragm in relation to the lungs.  Contraction of the diaphragm enlarges the thoracic cavity and pulls air into the lungs.  Remember that only mammals have a true muscular diaphragm; other terrestrial vertebrates use a variety of methods to inflate their lungs.
           Examine the lungs and note the pleural membranes (one lining the inner surface of the pleural cavity and the other covering the outer surface of the lung).  As mentioned earlier, the intrapleural space is filled with fluid.  This fluid allows the membranes to slide freely across each other, much like two wet panes of glass (easy to slide, hard to separate), and allows them to maintain contact.  This ensures that the lungs will inflate when the thoracic cavity expands as a result of diaphragmatic contraction or expansion of the rib cage.
           When neonatal mammals inhale for the first time, their lungs inflate.  When they then exhale, the lungs don’t deflate all the way.  That’s because pulmonary surfactants reduce the surface tension of water (just like soap does – you can float a bottlecap on water until you add a surfactant like soap).  In this case the water is in the form of a film that coats each and every alveolus.  If it weren’t for these surfactants, the surface tension of this layer would collapse the delicate alveoli – causing the lungs to “collapse” after each breath.  This surfactant is produced by the lungs during the last part of pregnancy.  
Think about it
1.      Why does the trachea have cartilaginous rings?
2.      Why is it important for air to be moist when it enters the lungs?  Many desert mammals have extremely convoluted nasal cavities.  How might these large and complex nasal cavities conserve water during exhalation?
3.      When you catch a cold, you get a runny nose.  Is snot your body’s way of combating a viral invader, or is the virus simply using you to reproduce and spread itself?  The common cold generally doesn't land you in bed:  is this evidence of you're own abilities to "fight" the virus, or is the virus manipulating you to maximize its exposure to uninfected individuals?
4.      What is the function of the eustachian tubes?
CIRCULATORY SYSTEM
Objectives
1.   Identify and describe the function of the main organs and structures in the circulatory system.
2.  Trace the flow of blood through the pulmonary and systemic circuits.
3.  Describe how the circulatory and respiratory systems work together to bring about the integrated functioning of the body.
4.  Understand portal circulation.
5.  Understand mammalian fetal circulation from a mechanical, physiological, and evolutionary perspective.
The circulatory (or cardiovascular) system is responsible for transporting nutrients, gases, hormones, and metabolic wastes to and from individual cells.  Actually, the loading and unloading take place in capillaries.  Oxygen is added to the blood (and carbon dioxide removed) in the capillaries of the lungs.  In the capillaries of the small intestine, nutrients are added to the blood, while in the capillaries of the kidneys the blood is cleansed of various metabolic wastes and excess ions.
In mammals, the circulatory system is divided into a pulmonary circuit, which involves blood flow to and from the lungs, and the systemic circuit, which involves blood flow to and from the rest of the body.  Your pig has been doubly injected (red for arteries, blue for veins).  However, note that in reality, arteries and veins are defined by the direction of blood flow, not by the oxygen content of the blood contained therein.
1.  The Heart (Fig. 6)
           You may remove as much thymus as you need to in order to view the heart.  Carefully remove the pericardial sac from the heart.  In living animals, the pericardial cavity is filled with fluid that acts as a shock absorber to protect the heart from injury.  Identify the coronary artery and coronary vein lying in the diagonal groove between the 2 ventricles.  These vessels supply and drain the heart (the heart is a muscle and as such has the same requirements of any other organ).  When the coronary artery becomes obstructed, a heart attack may occur.  It is the coronary arteries that are "bypassed" in coronary bypass surgery.  Note that the atria have external flaps, known as auricles.
In an adult mammal (fetal circulation will be discussed below), deoxygenated blood flows into the right atrium from the anterior and posterior vena cavae.  It then makes the following circuit:  right ventricle, pulmonary trunk, pulmonary artery, lungs, pulmonary vein, left atrium, left ventricle, aortic arch, aorta, and on into the systemic circulation.  On the heart model, trace this path and find the above as well as the following structures:
• right atrioventricular valve
• atrioventricular valve
• right semilunar valve (between right ventricle and pulmonary trunk)
• left semilunar valve (between left ventricle and aorta)
• papillary muscles:  support chordae tendinae
• chordae tendinae:  support AV valves, preventing eversion
2.  Major veins of the systemic circulation, anterior to the heart (Fig. 7a)
           Following the path of deoxygenated blood, find the external jugular vein, which drains the head and neck, and the internal jugular vein, which drains the brain.  Note the vagus nerve running between the right common carotid artery and the internal jugular vein (the vagus nerve is responsible for slowing the heart, constricting bronchi, and stimulating the stomach and gallbladder).  The jugular veins meet with the subclavian vein to form the brachiocephalic vein.  The right and left brachiocephalic veins join to form the anterior (cranial) vena cava.  Note, however, that the mass of veins (and arteries yLove Datingnakedfemales En Meetings Php Dating Naked Females iB::الموضوع::أحتاج لمساعدة عاج n a a Dating Naked Females Dating aLove Datingnakedfemales En Meetings Php Dating Naked Females iB::الموضوع::أحتاج لمساعدة عاج u j Females w Females Females Dating

منذ تاريخ 1/1/1423هـ