The Pathway of Air from the Nostrils to the Alveoli in the Fetal Pig
The nasal passages are separated from each other bt the nasal septum. The curved
turbinate bones in the sinus area increase the surface area of the passageways, creating
eddy currents that , along with hairs, cilia and mucus, help remove dust in the inhaled air
and humidify it.
Air enters the nasopharynx from the posterior end of the nasal passages, then
passes into the pharynx, through the glottis, and into the larynx and ultimately the trachea.
Air then passes through the voice box and over the vocal cords which vibrate when air
passes over them.
The diaphragm is a sheet of muscle that seperates the abdonimal cavity from the
thoracic cavity. The thoracic cavity is divided into three areas by membranes: The right
and left pleural cavities, which surround the lungs, and the pericardial cavity where the
heart is located.
The trachea, when it enters the thorax, divides into two bronchi. These bronchi
divide into progressively smaller bronchioles. which finally end in micrscopic air sacs
called alveoli. In these air sacs, oxygen and carbon dioxide are exchanged between the
blood and the inhaled air.
25-4 Describe how the diaphragm and rib cage function in moving air into and out
of a mammal's lungs.
Air enters the lungs as a result of the combined effects of the contraction of the
diaphragm and 3 sets of muscle: sternocleidomastoid, pectoralis minor and intercostal.
When these muscles contract, the volume of the thoracic cavity increases as the rib cage
elevates and the diaphragm depresses, causing the air pressure in the cavity to decrease.
Air rushes in through the respiratory passageways and expands the alveol...
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...rm progressively larger veins.
Ultimately, the veins converge into two large veins: the inferior vena cava, bringing blood
from the lower half of the body; and the superior vena cava, bringing blood from the upper
half. Both of these two large veins join at the right atrium of the heart.
Because the pressure is dissipated in the arterioles and capillaries, blood in veins
flows back to the heart at very low pressure, often running uphill when a person is
standing. Flow against gravity is made possible by the one-way valves, located several
centimeters apart, in the veins. When surrounding muscles contract, for example in the calf
or arm, the muscles squeeze blood back toward the heart. If the one-way valves work
properly, blood travels only toward the heart and cannot lapse backward. The precapillary
sphincter controls whether blood enters a capillary.
The contraction of the inspiratory muscles increases the volume of the thoracic cavity causing the pressure within the alveoli to decrease and air to flow into the alveoli. During resting inspiration, the diaphragm, the external intercostals and the parasternal intercostals contract to stimulate inspiration. During forced inspiration the scalene and the sternocleidomastoid muscles contract to further expand the thoracic cavity. The pectoralis minor muscles also play a minor role in forced inspiration. During quiet breathing, relaxation of these muscles causes the volume of the thoracic cavity to decrease, resulting in expiration. During a forced expiration, the compression of the chest cavity is increased by contraction of the internal intercostal muscles and various abdominal
The normal Mitral Valve controls blood flow between the upper (left atrium) and lower chamber (left ventricle) of the left side of the heart. The mitral valve allows blood to flow from the left atrium into the left ventricle, but not flow the other way. With each heartbeat, the atria contract and push blood into the ventricles. The flaps of the mitral and tricuspid valves open to let blood through. Then, the ventricles contract to pump the blood out of the heart. The flaps of the mitral and tricuspid valves close and form a tight seal that prevents blood from flowing back into the atria (nhlbi.nih.gov).
The blood circulates through coronary arteries and then to smaller vessels into cardiac muscle (myocardium). The blood flow is influenced by aortic pressure, which increases in systole, and the pumping activity of the ventricles. When the ventricle contracts, in systole, the coronary vessels are compressed by the contracted myocardium and partly blocked by the open aortic valve therefore the blood flow through the myocardium stops.
like a heart, and pumps haemolymph toward the head, thus driving the circulation of the
Healthy lung tissue is predominately soft, elastic connective tissue, designed to slide easily over the thorax with each breath. The lungs are covered with visceral pleura which glide fluidly over the parietal pleura of the thoracic cavity thanks to the serous secretion of pleural fluid (Marieb, 2006, p. 430). During inhalation, the lungs expand with air, similar to filling a balloon. The pliable latex of the balloon allows it to expand, just as the pliability of lungs and their components allows for expansion. During exhalation, the volume of air decrease causing a deflation, similar to letting air out of the balloon. However, unlike a balloon, the paired lungs are not filled with empty spaces; the bronchi enter the lungs and subdivide progressively smaller into bronchioles, a network of conducting passageways leading to the alveoli (Marieb, 2006, p. 433). Alveoli are small air sacs in the respiratory zone. The respiratory zone also consists of bronchioles and alveolar ducts, and is responsible for the exchange of oxygen and carbon dioxide (Marieb, 2006, p. 433).
The airway includes the nose, mouth, pharynx, larynx, trachea, bronchi, and bronchioles. It carries air between the lungs and the outside elements that surround the body. The lungs are the functional units of the respiratory system and they act as such. They pass oxygen into the body and remove carbon dioxide from the body. Then there are the muscles of respiration. These muscles include the diaphragm and intercostal muscles. They work simultaneously as a pump, pushing air into and out of the lungs during breathing.
Once the atrium contracts, blood cannot flow back into or enter the atria because the openings of the great veins have been narrowed by pressure. The ventricles are now filled with blood, accomplishing end-diastolic volume, which is another term for how much blood your ventricles can contain while your body is at rest. The next phase is early ventricular systole. Now that all the blood is in your ventricles, it must continue onward to the arterial trunk.
The nose is divided into the right and left cavities and is lined with tiny hairs and mucous membrane, which secretes a sticky fluid, called mucus, which helps prevent dust and bacteria from entering the lungs. The nose moistens, warms and filters the air and is an organ, which senses smell. The naso-pharynx is the upper part of the nasal cavity behind the nose, and is lined with mucous membrane. The naso-pharynx continues to filter, warm and moisten the incoming air.
When breathing occurs, air enter through the mouth or/and nose and passes through the pharynx, larynx, and trachea. At this point in the body, the trachea splits off into the right and left bronchi....
Every cell in the human body requires oxygen to function, and the lungs make that oxygen available. With every breath we take, air travels to the lungs through a series of tubes and airways. After passing through the mouth and throat, air moves through the larynx, commonly known as the voice box, and then through the trachea, or windpipe. The trachea divides into two branches, called the right bronchus and the left bronchus, that connect directly to the lungs. Air continues through the bronchi, which divide into smaller and smaller air passages in the lungs, called bronchioles. The bronchioles end in clusters of tiny air sacs, called alveoli, which are surrounded by tiny, thin-walled blood vessels called capillaries.
Through performing dissections, the interrelationships between functioning systems can be further understood. In the dissection of the fetal pig, three interrelationships can be defined: cardiovascular and respiratory, digestive and excretory, and digestive and cardiovascular.
The heart is two sided and has four chambers and is mostly made up of muscle. The heart’s muscles are different from other muscles in the body because the heart’s muscles cannot become tired, so the muscle is always expanding and contacting. The heart usually beats between 60 and 100 beats per minute. In the right side of the heart, there is low pressure and its job is to send red blood cells. Blood enters the right heart through a chamber which is called right atrium. The right atrium is another word for entry room. Since the atrium is located above the right ventricle, a mixture of gravity and a squeeze pushes tricuspid valve into the right ventricle. The tricuspid is made up of three things that allow blood to travel from top to bottom in the heart but closes to prevent the blood from backing up in the right atrium.
When you breathe in, air containing carbon dioxide (CO2) and oxygen (O2) it moves down your trachea; a tunnel containing cartilage and smooth tissue. Air then travels through two hollow tubes called bronchi; narrow branches lined with smooth muscle, mucosal and ringed cartilage to support the structure. The bronchi divide out into smaller tunnels called bronchioles; are small branches 0.5-1mm, lined with muscular walls to help dilate and constrict the airway. At the end of the bronchioles are little air sacs called alveoli; which assist in gas exchange of O2 and CO2. (Eldridge, 2016) Towards the end of alveoli are small blood vessel capillaries. O2 is moved through the blood stream through theses small blood vessels (capillaries) at the end of the alveoli and the CO2 is then exhaled. (RolandMedically,
the aortic valve, between the left ventricle and the aorta. heart_chambers.jpg Each valve has a set of "flaps" (also called leaflets or cusps). The mitral valve normally has two flaps; the others have three flaps. Dark bluish blood, low in oxygen, flows back to the heart after circulating through the body. It returns to the heart through veins and enters the right atrium.
There are two articulators that combine in the production of a consonant : an active organ (articulator) which is a movable one that moves towards the second organ (articulator) which is a passive one (or unmovable one) to form a blockage in the passage of the airstream and cause an audible friction. This blockage may be complete or partial (Omar, 1997:132-135). Since, there is a complete blockage at some points in the vocal tract i.e. , the oral cavity, nasal articulation requires a free passage of airstream which is the nose (i.e., the nasal cavity) (Robins, 2014: 84). Consonants are articulated either with a total obstruction of the air passage or with a narrow oral passage so that the air 43 escapes with friction. Consonants are classified depending on the state of the glottis (the vocal cords) during their articulation, the place of articulation and the manner in which a sound is articulated (Al-Hattimi, 2010: 272 and Todd, 1987:14).