Today we are going to continue with the lymphatic system and the respiratory system.
The Lymphatic System maintains the fluid balance in tissues, absorbs fats from the small intestine, and defends against microorganisms and foreign substances. It consists of lymph, lymph nodes, lymphocytes, lymphatic vessels, spleen, tonsils, and thymus.
Lymphatic vessels carry lymph (3 L of fluid that enters the lymphatic capillaries) away from tissues. Valves in the vessels ensure the one-way flow of lymph. Skeletal muscle contraction, contraction of of lymphatic vessel smooth muscle, and thoracic pressure changes move the lymph through the vessels. The thoracic duct and right lymphatic duct empty lymph into the blood.
The Lymphatic System maintains the fluid balance in tissues, absorbs fats from the small intestine, and defends against microorganisms and foreign substances. It consists of lymph, lymph nodes, lymphocytes, lymphatic vessels, spleen, tonsils, and thymus.
Lymphatic vessels carry lymph (3 L of fluid that enters the lymphatic capillaries) away from tissues. Valves in the vessels ensure the one-way flow of lymph. Skeletal muscle contraction, contraction of of lymphatic vessel smooth muscle, and thoracic pressure changes move the lymph through the vessels. The thoracic duct and right lymphatic duct empty lymph into the blood.
Lymphatic tissue produces lymphocytes when exposed to foreign substances, and it filters lymph and blood.
The tonsils protect the openings between the nasal and oral cavities and the pharynx. There are three groups of tonsils: palatine (usually referred to as "the tonsils", found on each side of the posterior opening of the oral cavity), pharyngeal (found near the internal opening of nasal cavity, commonly called adenoid when enlarged), and lingual (posterior surface of the tongue).
The tonsils protect the openings between the nasal and oral cavities and the pharynx. There are three groups of tonsils: palatine (usually referred to as "the tonsils", found on each side of the posterior opening of the oral cavity), pharyngeal (found near the internal opening of nasal cavity, commonly called adenoid when enlarged), and lingual (posterior surface of the tongue).
Lymph nodes are located along the lymphatic vessels. They filter lymph.
The white pulp of the spleen responds to foreign substances in the blood, whereas the red pulp phagocytizes foreign substances and worn-out red blood cells. The spleen is also the blood reservoir.
The thymus processes lymphocytes that move to other lymphatic tissue to respond to foreign substances.
Here is an overview of the Lymphatic System.
Immunity is the ability to resist the harmful effects of microorganisms and other foreign substances. It is classified as innate or adaptive.
There are four ways to acquire adaptive immunity:
- Innate Immunity is accomplished by physical barriers, chemical mediators, white blood cells, and the inflammatory response.
- Adaptive Immunity is stimulated by molecules called antigens. B cells are responsible for anti-body mediated immunity; T cells are involved with cell-mediated immunity.
There are four ways to acquire adaptive immunity:
- Active natural immunity results from everyday exposure to an antigen against which the person's own immune system mounts a response.
- Active artificial immunity results from deliberate exposure to an antigen (vaccine) to which the person's own immune system responds.
- Passive natural immunity is the transfer of antibodies from a mother to her fetus during gestation or to her baby during breastfeeding.
- Passive artificial immunity is the transfer of antibodies from an animal or another person to a person requiring immunity.
Immune Interactions
Innate immunity, antibody-mediated immunity, and cell-mediated immunity can function together to eliminate an antigen.
Innate immunity, antibody-mediated immunity, and cell-mediated immunity can function together to eliminate an antigen.
Immunotherapy stimulates or inhibits the immune system to treat diseases.
Some disease and disorders associated with the lymphatic system.
Some disease and disorders associated with the lymphatic system.
Next up is the respiratory system.
The Respiratory System exchanges oxygen and carbon dioxide between the air and the blood, regulates blood pH, helps produce sounds, moves air over the sensory receptors that detect smell, and protects against some microorganisms.
Respiration includes ventilation (breathing), which is the movement of air into and out of the lungs, the exchange of oxygen and carbon dioxide between the air in the lungs and the blood, the transport of oxygen and carbon dioxide in the blood, and the exchange of oxygen and carbon dioxide between blood and tissues.
The Anatomy of the Respiratory System.
The Respiratory System exchanges oxygen and carbon dioxide between the air and the blood, regulates blood pH, helps produce sounds, moves air over the sensory receptors that detect smell, and protects against some microorganisms.
Respiration includes ventilation (breathing), which is the movement of air into and out of the lungs, the exchange of oxygen and carbon dioxide between the air in the lungs and the blood, the transport of oxygen and carbon dioxide in the blood, and the exchange of oxygen and carbon dioxide between blood and tissues.
The Anatomy of the Respiratory System.
Ventilation (breathing) is the process of moving air into and out of the lungs. It has two phases:
Changing Thoracic Volume
Inspiration occurs when the diaphragm contracts and the external intercostal muscles lift the rib cage, thus increasing the volume of the thoracic cavity. During labored breathing, additional muscles of inspiration increase rib movement.
Expiration can be passive or active. Passive expiration during quiet breathing occurs when the muscle of inspiration relax. Active expiration during labored breathing occurs when the diaphragm relaxes and the internal intercostal and abdominal muscles depress the rib cage to forcefully decrease the volume of the thoracic cavity.
- Inspiration (inhalation) is the movement of air into the lungs
- Expiration (exhalation) is the movement of air out of the lungs
Changing Thoracic Volume
Inspiration occurs when the diaphragm contracts and the external intercostal muscles lift the rib cage, thus increasing the volume of the thoracic cavity. During labored breathing, additional muscles of inspiration increase rib movement.
Expiration can be passive or active. Passive expiration during quiet breathing occurs when the muscle of inspiration relax. Active expiration during labored breathing occurs when the diaphragm relaxes and the internal intercostal and abdominal muscles depress the rib cage to forcefully decrease the volume of the thoracic cavity.
Pressure Changes and Airflow
Respiratory muscles cause changes in thoracic volume, which in turn cause changes in alveolar volume and pressure. During inspiration, air flows into the alveoli because atmospheric pressure is greater than alveolar pressure while during expiration, air flows out the of the alveoli because alveolar pressure is greater than the atmospheric pressure.
Respiratory muscles cause changes in thoracic volume, which in turn cause changes in alveolar volume and pressure. During inspiration, air flows into the alveoli because atmospheric pressure is greater than alveolar pressure while during expiration, air flows out the of the alveoli because alveolar pressure is greater than the atmospheric pressure.
Lung Recoil
The lungs tend to collapse because of the elastic recoil of the connective tissue and the surface tension of the fluid lining the alveoli. The lungs don’t normally collapse because the surfactant reduces the surface tension of the fluid lining the alveoli, and pleural pressure is lower than alveolar pressure.
Changing Alveolar Volume
Increasing thoracic volume results in decreased pleural pressure, increased alveolar volume, decreased alveolar pressure, and air movement into the lungs. Decreasing thoracic volume results in increased pleural pressure, decreased alveolar volume, increased alveolar pressure, and air movement out of the lungs.
Respiratory Volumes and Capacities
There are four measurements of respiratory volume: tidal, inspiratory reserve, expiratory reserve, and residual. Respiratory capacities are the sum of two or more respiratory volumes; they include vital capacity and total lung capacity. The forced expiratory vital capacity measures the rate at which air can be expelled from the lungs.
The lungs tend to collapse because of the elastic recoil of the connective tissue and the surface tension of the fluid lining the alveoli. The lungs don’t normally collapse because the surfactant reduces the surface tension of the fluid lining the alveoli, and pleural pressure is lower than alveolar pressure.
Changing Alveolar Volume
Increasing thoracic volume results in decreased pleural pressure, increased alveolar volume, decreased alveolar pressure, and air movement into the lungs. Decreasing thoracic volume results in increased pleural pressure, decreased alveolar volume, increased alveolar pressure, and air movement out of the lungs.
Respiratory Volumes and Capacities
There are four measurements of respiratory volume: tidal, inspiratory reserve, expiratory reserve, and residual. Respiratory capacities are the sum of two or more respiratory volumes; they include vital capacity and total lung capacity. The forced expiratory vital capacity measures the rate at which air can be expelled from the lungs.
Gas Exchange
Gas exchange between air and the blood occurs in the respiratory membrane. The parts of the respiratory passageways where gas exchange between air and blood does not occur constitute the dead space. The exchange of gases across the respiratory membrane is influenced by:
Gas exchange between air and the blood occurs in the respiratory membrane. The parts of the respiratory passageways where gas exchange between air and blood does not occur constitute the dead space. The exchange of gases across the respiratory membrane is influenced by:
- Respiratory Membrane Thickness
- Surface Area
- Partial Pressure
Gas Transport in the Blood
In Oxygen Transport, most oxygen (98.5%) is transported bound to hemoglobin. Some (1.5%) are transported dissolved in plasma. Oxygen is released from hemoglobin in tissues when the partial pressure for oxygen is low, the partial pressure for carbon dioxide is high, pH is low, and temperature is high.
In Carbon Dioxide Transport, carbon dioxide is transported in solution as plasma (7%), in combination with blood proteins (23%), and as bicarbonate ions (70%). In tissue capillaries, carbon dioxide combines with water inside the red blood cells to form carbonic acid that dissociates to form HCO₃- and H+. This reaction promotes the transport of carbon dioxide. In lung capillaries, HCO₃- combines with H+ to form carbonic acid that dissociates to form carbon dioxide, which diffuses out of the red blood cells.
In Oxygen Transport, most oxygen (98.5%) is transported bound to hemoglobin. Some (1.5%) are transported dissolved in plasma. Oxygen is released from hemoglobin in tissues when the partial pressure for oxygen is low, the partial pressure for carbon dioxide is high, pH is low, and temperature is high.
In Carbon Dioxide Transport, carbon dioxide is transported in solution as plasma (7%), in combination with blood proteins (23%), and as bicarbonate ions (70%). In tissue capillaries, carbon dioxide combines with water inside the red blood cells to form carbonic acid that dissociates to form HCO₃- and H+. This reaction promotes the transport of carbon dioxide. In lung capillaries, HCO₃- combines with H+ to form carbonic acid that dissociates to form carbon dioxide, which diffuses out of the red blood cells.
As blood carbon dioxide levels increase, blood pH decreases and while blood carbon dioxide levels decrease, blood pH increases. Changes in breathing change blood carbon dioxide levels and pH.
Some disease and disorders associated with the respiratory system.
Some disease and disorders associated with the respiratory system.
That's it for this post. We are nearing the end of the subject matter. Please do return so you could complete all the systems in the body. Again, be sure to leave your comments and suggestions.