Anatomy II Test 2 Part 1

Pulmonary arteries carry blood to the lungs. This is because the pulmonary arteries are responsible for transporting deoxygenated blood from the heart to the lungs, where it can be oxygenated. Once the blood reaches the lungs, it undergoes gas exchange, where carbon dioxide is removed and oxygen is taken in. This oxygenated blood is then returned to the heart via the pulmonary veins and is pumped out to the rest of the body through the systemic circuit. Therefore, the correct answer is "lungs."

The thoracic duct is responsible for returning most of the lymph to the venous circulation. This large lymphatic vessel collects lymph from the lower limbs, abdomen, left side of the thorax, left upper limb, and left side of the head and neck. It then drains into the left subclavian vein, where it merges with the venous circulation. The other options, such as the dural sinus, right lymphatic duct, cisterna chyli, and hepatic portal vein, are not directly involved in returning lymph to the venous circulation.

Carbon dioxide is transported in the blood in various forms, but the majority of it is converted into bicarbonate ions. When carbon dioxide enters the red blood cells, it reacts with water to form carbonic acid, which then dissociates into bicarbonate ions and hydrogen ions. The bicarbonate ions are then transported out of the red blood cells and into the plasma, where they are carried to the lungs to be exhaled. This process helps to maintain the balance of carbon dioxide in the blood and regulate pH levels.

B cells are responsible for humoral immunity. They are a type of white blood cell that produce and secrete antibodies, which are proteins that help to neutralize pathogens and toxins in the body. B cells are activated when they encounter an antigen, and they then differentiate into plasma cells that produce and release antibodies. These antibodies circulate in the blood and lymph, binding to specific antigens and marking them for destruction by other immune cells. B cells are an essential component of the adaptive immune response and play a crucial role in defending against infections.

The bladder is not a component of the digestive tract. The digestive tract consists of organs involved in the digestion and absorption of food, including the stomach, pharynx, esophagus, and colon. The bladder, on the other hand, is part of the urinary system and is responsible for storing and eliminating urine.

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A high level of pyrogens in John's blood indicates that he is running a fever. Pyrogens are substances that can cause the body's temperature to increase, leading to fever. This suggests that John's body is fighting off an infection or illness, as fevers are often a response to infection. The other options, such as sore throat, swollen lymph nodes, T lymphocyte production, or feeling achy, do not directly relate to the presence of pyrogens in the blood.

The trachea is the correct answer because it is the airway that connects the larynx (voice box) to the bronchial tree, which includes the bronchi and bronchioles. The trachea is a tube made of cartilage rings that allows air to pass through and reach the lungs. It is an important part of the respiratory system and plays a crucial role in the process of breathing.

The correct answer is "movement of air into and out the alveoli." Alveolar ventilation refers to the exchange of air between the alveoli and the external environment. This process involves inhaling oxygen-rich air into the alveoli and exhaling carbon dioxide-rich air out of the alveoli. It is an essential mechanism for maintaining proper gas exchange in the lungs, allowing oxygen to enter the bloodstream and carbon dioxide to be eliminated from the body.

Three pairs of salivary glands secrete into the oral cavity. Each pair includes the parotid glands, submandibular glands, and sublingual glands. These glands are responsible for producing saliva, which helps in the digestion process by moistening food and breaking it down chemically. Saliva also contains enzymes that aid in the initial breakdown of carbohydrates.

The primary bronchi are the first branches of the trachea, forming the division between the trachea and the lungs. They are responsible for carrying air into the lungs. The other options listed are not the correct answer because they do not accurately describe the branching pattern of the bronchi from the trachea.

Pepsin is an enzyme that is primarily responsible for breaking down proteins in the stomach. It works by breaking the peptide bonds between amino acids, resulting in the digestion of proteins into smaller peptides. This process is essential for the body to absorb and utilize the amino acids from proteins for various physiological functions. Therefore, the correct answer is proteins.

The pulmonary veins carry oxygenated blood from the lungs back to the heart. This blood is then pumped into the left atrium, which is one of the four chambers of the heart. From the left atrium, the blood flows into the left ventricle and is then pumped out to the rest of the body through the aorta. Therefore, the correct answer is left atrium.

Edema is favored when endothelial permeability goes up, capillary hydrostatic pressure is elevated, and the plasma concentration of protein is reduced. These factors contribute to an increase in the movement of fluid from the blood vessels into the surrounding tissues, leading to the accumulation of fluid and the development of edema. Therefore, options a, b, and c are all correct explanations for why edema may occur.

NK cells, also known as natural killer cells, are responsible for immunological surveillance. They play a crucial role in the immune system by identifying and eliminating infected or abnormal cells, such as cancer cells. Unlike other immune cells, NK cells do not require prior activation and can directly recognize and destroy target cells. Therefore, NK cells are the correct answer as they are specifically involved in immunological surveillance.

Boyle's law states that the volume of a gas is inversely proportional to its pressure. This means that as the pressure on a gas increases, its volume decreases, and vice versa. This relationship is described by the equation PV = k, where P is the pressure, V is the volume, and k is a constant. Therefore, the correct answer is "inversely proportional to pressure."

The correct answer is "movement of air into and out the lungs." Pulmonary ventilation is the process of breathing, which involves the movement of air into and out of the lungs. This process allows for the exchange of gases, such as oxygen and carbon dioxide, between the lungs and the external environment.

The lamina propria and mucous epithelium are components of the mucosa. The mucosa is the innermost layer of the gastrointestinal tract and is responsible for the secretion of mucus, absorption of nutrients, and protection of the underlying tissues. The lamina propria is a layer of connective tissue that supports the mucous epithelium and contains blood vessels, lymphatic vessels, and immune cells. The mucous epithelium is a layer of specialized cells that secrete mucus, which helps lubricate and protect the gastrointestinal tract. Therefore, the correct answer is mucosa.

The mesenteries are double sheets of peritoneal membrane that suspend the visceral organs and carry nerves, lymphatics, and blood vessels. They provide support and stability to the organs within the abdominal cavity, allowing them to move and function properly. The mesenteries also play a role in the transport of nutrients and waste products between the organs and the rest of the body.

IgG is the correct answer because it is the most abundant immunoglobulin and plays a crucial role in providing resistance against various viruses, bacteria, and bacterial toxins. IgG antibodies are able to neutralize pathogens, enhance phagocytosis, and activate the complement system, making them highly effective in immune defense. Additionally, IgG is the only immunoglobulin that can cross the placenta, providing passive immunity to newborns.

Passive immunization involves the transfer of pre-formed antibodies from one individual to another. In this case, the rabbit produces antibodies in response to the viral antigen and these antibodies are purified and injected into a human with the same viral disease. This provides immediate protection to the human by providing them with ready-made antibodies to fight against the virus. It is a form of immunization that does not involve the individual's own immune response and is therefore considered passive.

Tuberculosis is a bacterial infection caused by the bacterium Mycobacterium tuberculosis. This bacterium primarily affects the lungs but can also spread to other parts of the body. Vancomycin-resistant streptococcus, Clostridium difficile, and straphyloccus aureus are not associated with tuberculosis. Therefore, the correct answer is Mycobacterium tuberculosis.

The pancreas is an accessory organ of digestion because it produces digestive enzymes that are essential for breaking down carbohydrates, proteins, and fats in the small intestine. These enzymes help in the process of digestion and absorption of nutrients. Additionally, the pancreas also produces insulin and glucagon, which are hormones involved in regulating blood sugar levels.

The fundus is the portion of the stomach that is located above the junction between the stomach and the esophagus. It is the uppermost part of the stomach, located towards the left side of the body. The fundus is responsible for storing and releasing gases that are produced during digestion. It also helps in the digestion of food by secreting certain enzymes and acids. The other options, such as pulorus, antrum, body, and cardia, do not accurately describe the portion of the stomach that is superior to the junction with the esophagus.

Lymphocytes are a type of white blood cell that play a crucial role in the immune system. They are primarily found in lymphoid tissue, such as lymph nodes and the spleen, where they carry out their immune functions. Additionally, lymphocytes have relatively long life spans compared to other blood cells, allowing them to provide long-term immunity. Therefore, the correct answer is "a and b only" as lymphocytes spend most of their time in lymphoid tissue and have relatively long life spans.

The auditory tubes, also known as the Eustachian tubes, connect the middle ear to the nasopharynx. These tubes help equalize pressure between the middle ear and the atmosphere. When we swallow or yawn, the auditory tubes open, allowing air to flow in and out of the middle ear. The nasopharynx is the upper part of the throat that lies behind the nose and above the soft palate. Therefore, the correct answer is nasopharynx.

A tracheostomy is the placement of a tube directly into the trachea to bypass the larynx. This procedure is performed to create an alternate airway for patients who have difficulty breathing or require long-term ventilation. Intubation, catheterization, tunnelization, and trachectomy are not the correct terms for this procedure.

Secondary bronchi supply air to the lobes of the lungs. The bronchi are the main airways that branch off from the trachea and enter the lungs. The secondary bronchi are the branches that supply air to each lobe of the lungs. The lobes of the lungs are distinct sections that make up the lungs, with the right lung having three lobes and the left lung having two lobes. Therefore, the secondary bronchi are responsible for delivering air to each lobe of the lungs.

The blood colloid osmotic pressure is primarily determined by the concentration of plasma proteins. These proteins, such as albumin, exert an osmotic force that helps to maintain fluid balance within the blood vessels. When the concentration of plasma proteins is low, as in conditions like liver disease or malnutrition, the blood colloid osmotic pressure decreases, leading to fluid accumulation in the tissues and causing edema. Therefore, the concentration of plasma proteins plays a crucial role in regulating the blood colloid osmotic pressure.

Cystic fibrosis is the most common lethal inherited disease among individuals of Northern European descent. This genetic disorder primarily affects the lungs and digestive system, causing thick and sticky mucus to build up in these organs. This can lead to severe respiratory and gastrointestinal complications, making it a life-threatening condition. The prevalence of cystic fibrosis is higher in individuals of Northern European descent due to the higher frequency of the gene mutation that causes the disease in this population.

Metabolites exchange by diffusion with tissue cells in capillaries. Capillaries are the smallest blood vessels with thin walls, allowing for efficient exchange of nutrients, gases, and waste products between the blood and surrounding tissues. This exchange occurs through the process of diffusion, where molecules move from an area of high concentration (blood) to an area of low concentration (tissue cells). Capillaries have a large surface area and slow blood flow, facilitating this exchange process. Therefore, capillaries are the primary location for metabolite exchange with tissue cells.

After passing the first rib, the subclavian artery continues its course and becomes the axillary artery. The axillary artery is a major blood vessel that supplies blood to the upper limb. It begins at the lateral border of the first rib and extends to the lower border of the teres major muscle. It is responsible for providing oxygenated blood to the shoulder, chest wall, and upper arm.

The correct answer is A+B. In IgG, the antigen binding site is formed by the variable segment of the heavy chain (A) and the variable segment of the light chain (B). The variable segments of both the heavy and light chains contain hypervariable regions that are responsible for recognizing and binding to specific antigens. This allows IgG to effectively target and neutralize foreign substances in the body.

The correct answer is jejunum. The small intestine is divided into three segments: duodenum, jejunum, and ileum. The jejunum is the middle segment, located between the duodenum and the ileum. It is responsible for the majority of nutrient absorption in the small intestine. The duodenum is the first segment of the small intestine, the ileum is the last segment, and the pylorus is the opening that connects the stomach to the small intestine. The cecum is the beginning of the large intestine.

IgM antibodies are the first antibodies to be produced in response to an infection. They are made up of five subunits and are involved in the primary immune response. IgM antibodies are produced by B cells and are effective at neutralizing pathogens and activating other components of the immune system. They are typically found in higher levels during the early stages of an infection and then decrease as other antibodies, such as IgG, are produced.

The release of renin is not expected to lead to a decrease in blood pressure. Renin is an enzyme that is released by the kidneys when there is a decrease in blood flow or a decrease in sodium levels. Its primary function is to initiate the renin-angiotensin-aldosterone system, which ultimately leads to an increase in blood pressure. Therefore, the release of renin would actually cause an increase in blood pressure, making it the exception among the given options.

The spleen is the largest single collection of lymphoid tissue in the adult body. It plays a crucial role in the immune system by filtering the blood and removing old or damaged red blood cells. It also helps in the production of white blood cells and antibodies, which are essential for fighting off infections and diseases. The spleen acts as a reservoir for blood, storing and releasing it when needed. Additionally, it helps in the destruction of bacteria and other foreign substances. Therefore, the spleen is the correct answer as it houses the largest amount of lymphoid tissue in the adult body.

The human immunodeficiency virus (HIV) selectively infects helper T cells. Helper T cells play a crucial role in the immune response by coordinating the actions of other immune cells. HIV specifically targets these cells because they have a protein called CD4 on their surface, which acts as a receptor for the virus. By infecting and killing helper T cells, HIV weakens the immune system and leads to the development of AIDS.

The correct answer is cerebral arterial circle. The cerebral arterial circle, also known as the Circle of Willis, is an anastomosis of blood vessels located at the base of the brain. It connects the internal carotid arteries and the basilar artery, allowing for collateral circulation and equal distribution of blood flow to the brain. This circle of blood vessels helps to ensure that even if one of the major arteries supplying the brain becomes blocked or damaged, blood can still reach all areas of the brain through alternative routes.

The correct answer is celiac trunk. The celiac trunk is a major branch of the abdominal aorta that supplies blood to the upper abdominal organs, including the stomach, liver, spleen, and pancreas. It is located just below the diaphragm and is responsible for delivering oxygenated blood to these organs.

The correct answer is axillary. The axillary vein is located in the armpit region and is responsible for draining blood from the upper limb. It is a continuation of the basilic vein and becomes the subclavian vein as it travels towards the heart. The brachial, median cubital, basilic, and cephalic veins are also present in the upper limb, but they are not labeled as vein number 9.

The classic pathway of complement activation begins when the protein C1 binds to an antibody attached to an antigen. This is because C1 recognizes and binds to the Fc region of the antibody, which is attached to the antigen. This binding triggers a cascade of reactions that leads to the activation of other complement proteins and the formation of the membrane attack complex, ultimately resulting in the destruction of the target cell.

The oral cavity is responsible for several functions related to food processing and digestion. It is involved in the analysis of material, digestion of carbohydrates, mechanical processing of food, and lubrication. However, absorption of monosaccharides does not occur in the oral cavity. Absorption of nutrients, including monosaccharides, primarily takes place in the small intestine. Therefore, absorption of monosaccharides is not a function of the oral cavity.

Cementum is the correct answer because it is the outer layer of the root of the tooth. It covers and protects the root, providing support and anchoring the tooth to the surrounding bone. Cementum is a hard, calcified tissue similar to bone, but it is not as hard as enamel. The pulp is the soft, innermost part of the tooth that contains nerves and blood vessels. Dentin is the layer beneath the enamel and cementum, while the root canal is the space inside the root of the tooth that contains the pulp.

The internal jugular vein is responsible for carrying blood from the brain back to the heart. It is a major vein located in the neck that runs alongside the carotid artery. The other options listed, such as the azygos, external jugular, vertebral, and innominate veins, are not directly involved in the drainage of blood from the brain to the heart.

Lymphadenopathy refers to a chronic or excessive enlargement of lymph nodes. This condition can occur due to various reasons such as infection, inflammation, or malignancy. When lymph nodes become enlarged, it usually indicates an immune response to an underlying problem in the body. The enlargement can be felt as lumps or bumps in certain areas of the body, such as the neck, armpits, or groin. It is important to identify the cause of lymphadenopathy to determine the appropriate treatment.

The complement system is a group of proteins that work together to enhance the immune response. Plasma contains various complement proteins, and the question is asking for the number of special complement proteins present in plasma. The correct answer is 11, indicating that there are 11 special complement proteins in plasma.

The correct answer is ulnar because it is a vein located in the forearm. It runs parallel to the ulna bone and is responsible for carrying deoxygenated blood back to the heart. The other options, such as axiallary, brachial, radial, and basilic, are not veins in the forearm.

The correct answer is "naturally acquired passive" because this type of immunity refers to the transfer of antibodies from a mother to her fetus through the placenta. This transfer occurs naturally and provides temporary protection to the newborn, as the antibodies are acquired from the mother rather than being produced by the baby's own immune system.

In Figure 22-1, the area labeled "6" is dominated by B cells. This can be inferred from the fact that B cells are a type of white blood cell that plays a crucial role in the immune response by producing antibodies. The other options, erythrocytes (red blood cells), T cells, and platelets, do not have the same function as B cells in the immune system. Therefore, B cells are the dominant cell type in the area labeled "6".

The palatine tonsils are located in the oropharynx. The oropharynx is the part of the throat that is located behind the mouth and above the laryngopharynx. It is responsible for conducting both food and air, and it plays a role in both digestion and respiration. The palatine tonsils are a pair of lymphoid tissue masses located on either side of the oropharynx, near the back of the throat. They play a role in the immune system by helping to defend against infections.

Carbon dioxide is the most important chemical regulator of respiration because it plays a crucial role in maintaining the pH balance of the blood. When carbon dioxide levels increase, it reacts with water to form carbonic acid, which lowers the pH of the blood. This change in pH is detected by chemoreceptors in the brain, which then signal the respiratory system to increase the rate and depth of breathing, allowing more carbon dioxide to be expelled from the body. Therefore, carbon dioxide acts as a powerful regulator of respiration, ensuring that the body maintains appropriate levels of this gas.

The villi are tiny finger-like projections in the small intestine that increase the surface area for absorption of nutrients. The jejunum is the middle part of the small intestine, located between the duodenum and ileum. It is the primary site for nutrient absorption and has the highest concentration of villi. Therefore, the jejunum is the most developed section of the small intestine in terms of villi.

Autoantibodies are produced by activated T cells. This is incorrect. Autoantibodies are actually produced by B cells, not T cells. Autoantibodies are directed against the body's own antigens, meaning they target and attack the body's own cells and tissues. This can lead to autoimmune diseases. Autoantibodies are not the first step in immunological competence, nor are they produced during an allergic reaction. They can, however, be important in tissue rejection reactions, as they can target and attack transplanted organs or tissues.

The correct answer is thyroid. The question is asking for the location to place a tracheostomy tube, and the tracheostomy tube is commonly placed through the ligament that connects the cricoid cartilage to the thyroid cartilage. The other options (epiglottic, cuneiform, vestibular, corniculate) are not directly involved in the placement of a tracheostomy tube.

When arterioles dilate, it means that the smooth muscles in the walls of the arterioles relax, allowing them to widen. This widening increases the diameter of the arterioles, which in turn increases blood flow to the tissue. This is because the increased diameter of the arterioles reduces resistance to blood flow, allowing more blood to reach the tissue. Therefore, the correct answer is arterioles dilate.

The term "blood pressure" clinically refers to the pressure exerted by the blood against the walls of the arteries. This is commonly measured using a sphygmomanometer and is expressed as systolic pressure over diastolic pressure. Arterial pressure specifically refers to the pressure within the arteries, which is an important indicator of cardiovascular health and can help diagnose conditions such as hypertension.

B cells are primarily activated by helper T cells. Helper T cells play a crucial role in the immune response by recognizing antigens presented by antigen-presenting cells (such as macrophages) and activating B cells. Once activated, B cells differentiate into plasma cells, which produce antibodies. Therefore, while antibodies and antigens are important components of the immune response, they do not directly activate B cells. Macrophages also contribute to the immune response, but they do not directly activate B cells.

The dominant cell type in the area labeled "4" is T cells.

The glottis refers to the opening to the larynx. It is the space between the vocal cords, which allows air to pass through when breathing or speaking. The glottis plays a crucial role in producing sound and controlling the flow of air into the respiratory system. It is not the opening to the pharynx, part of the hard palate, a flap of elastic cartilage, or the soft tissue that hangs off the end of the soft palate.

Class II MHC proteins are present in antigen-presenting cells and lymphocytes. These proteins play a crucial role in the immune response by presenting antigens to helper T cells. Antigen-presenting cells, such as macrophages, dendritic cells, and B cells, capture and process antigens, then display them on their surface using Class II MHC proteins. Lymphocytes, including helper T cells and B cells, also express Class II MHC proteins to recognize and respond to antigens. This allows for the activation of the immune system and the coordination of an effective immune response against infections or other foreign substances.

A vein that measures 5 mm would be considered a medium vein because it falls in the middle range of vein sizes. Veins can vary in size, with smaller ones called venules and larger ones called large veins. The given measurement of 5 mm indicates that it is not a smaller venule or a larger vein, but rather falls in the middle range, making it a medium vein.

The roof of the oral cavity is formed by the hard palate and the soft palate. The hard palate is the bony structure located at the front part of the roof, while the soft palate is the muscular structure located at the back part of the roof. Together, these structures create the roof of the oral cavity. Option A, the vestibule, is incorrect as it refers to the space between the lips or cheeks and the teeth or gums, not the roof of the oral cavity.

The artery labeled 1 is the brachiocephalic artery.

The correct answer is inferior vena cava. The inferior vena cava is a large vein that carries deoxygenated blood from the lower body back to the heart. It is located on the right side of the body and enters the right atrium of the heart.

The correct answer is the inferior vena cava. The two common iliac veins merge to form the inferior vena cava, which is a large vein that carries deoxygenated blood from the lower body to the right atrium of the heart. The inferior vena cava is an essential component of the circulatory system, playing a crucial role in returning blood to the heart for oxygenation.

When mast cells release histamine and heparin, it triggers an inflammatory response. Histamine is responsible for causing vasodilation, which increases blood flow to the affected area. This results in redness and warmth at the site of inflammation. Heparin helps to prevent blood clotting, allowing immune cells to move freely and fight off any pathogens present. Together, histamine and heparin play a crucial role in initiating and regulating the inflammatory response.

The conchae are structures in the nasal cavity that help create turbulence in the air we breathe. This turbulence serves to slow down and redirect the airflow, allowing particulate matter such as dust and pollen to be trapped in the mucus lining the nasal cavity. This helps to filter and clean the air before it reaches the lungs. Therefore, the conchae create turbulence in the air to trap particulate matter in mucus.

Hypercapnia refers to a condition where there is an elevated level of carbon dioxide (P02) in the blood. This can occur due to the cessation of breathing or labored breathing. Therefore, the correct answer is "all of the above" as hypercapnia can result from any of these situations.

A stratified squamous epithelial lining is a type of tissue that is found in areas of the body that experience a lot of wear and tear, such as the oral cavity, esophagus, oropharynx, and anal canal. However, the stomach is lined with a different type of tissue called simple columnar epithelium, which is better suited for its functions of secreting digestive juices and absorbing nutrients. Therefore, the correct answer is stomach.

When renin is released from the kidney, it initiates a cascade of reactions that ultimately lead to the conversion of angiotensinogen into angiotensin I. This conversion is an important step in the renin-angiotensin-aldosterone system (RAAS) pathway. Angiotensin I is then further converted to angiotensin II, which is a potent vasoconstrictor. Angiotensin II causes blood vessels to constrict, leading to an increase in blood pressure. Therefore, the correct answer is that angiotensinogen is converted into angiotensin I when renin is released from the kidney.

ADH (antidiuretic hormone) and aldosterone secretion are part of the body's long-term compensation for a serious hemorrhage. When a significant amount of blood is lost due to hemorrhage, the body responds by increasing the secretion of ADH and aldosterone. ADH helps to increase water reabsorption in the kidneys, reducing urine output and conserving water in the body. Aldosterone promotes the reabsorption of sodium and water in the kidneys, further helping to retain fluids. These compensatory mechanisms aim to maintain blood volume and blood pressure, which are significantly affected by hemorrhage.

The question is asking for the hormone of the immune system that is not included in the given list. The options provided are thymosins, interleukins, natriuretic factor, interferons, and tumor necrosis factor. The correct answer is tumor necrosis factor because it is not a hormone of the immune system. Tumor necrosis factor is a protein produced by immune cells and is involved in the regulation of inflammation and cell death, but it is not classified as a hormone.

The bulk of each tooth consists of a mineralized matrix similar to that of bone called dentin. Dentin is a hard, dense tissue that forms the majority of the tooth structure. It is located beneath the enamel, which is the outermost layer of the tooth, and surrounds the pulp, which contains the nerves and blood vessels. Dentin provides support and protection to the inner structures of the tooth and helps to transmit sensations such as temperature and pressure.

Incisors are blade-shaped teeth that are located at the front of the mouth. They have a sharp, thin edge that allows them to cut and slice through food. Incisors are primarily used for biting and cutting, making them essential for tasks such as tearing into meat or biting into an apple. They are typically the first teeth to erupt in a person's mouth and are responsible for creating a straight edge when the mouth is closed.

During a primary humoral response to antigens, several events occur. B cells may differentiate into plasma cells immediately, and they may also undergo several rounds of mitosis before producing plasma cells and memory cells. The first immunoglobulins to appear in circulation are of the IgM type. Antibody levels do not peak until 1 to 2 weeks after the initial exposure. However, neutrophils invading the surrounding areas and releasing chemotactic substances is not a part of the primary humoral response to antigens.

In response to hemorrhage, there is peripheral vasoconstriction and mobilization of the venous reserve. This means that the blood vessels in the peripheral parts of the body constrict, which helps to redirect blood flow to vital organs. Additionally, the body mobilizes the venous reserve, which refers to the extra blood that is stored in the veins and can be released to increase blood volume. Increased parasympathetic stimulation of the heart is not a response to hemorrhage.

Veins are blood vessels that carry deoxygenated blood back to the heart. They have a larger diameter and thinner walls compared to arteries, allowing them to hold a larger percentage of the blood supply. Arteries carry oxygenated blood away from the heart, capillaries are the smallest blood vessels where exchange of nutrients and waste occurs, venules are small veins that receive blood from capillaries, and arterioles are small arteries that regulate blood flow. Therefore, veins are the correct answer as they have the capacity to hold the largest percentage of the blood supply.

The artery labeled 9 is the common carotid artery. The common carotid artery is a major blood vessel located in the neck that supplies oxygenated blood to the head and neck region. It branches off into the internal carotid artery, which supplies blood to the brain, and the external carotid artery, which supplies blood to the face and neck muscles.

Stress can affect the immune response in several ways, including inhibiting interleukin secretion, increasing the level of glucocorticoids, depressing the inflammatory response, and reducing the number of phagocytes. However, it does not directly inhibit glucocorticoid release. Glucocorticoids are stress hormones that play a crucial role in regulating the immune system. They help to reduce inflammation and suppress immune responses. While stress can indirectly affect the release of glucocorticoids by activating the hypothalamic-pituitary-adrenal (HPA) axis, it does not directly inhibit their release.

Stimulation of the aortic baroreceptors reflex results in increased activity by the parasympathetic nervous system. Aortic baroreceptors are specialized nerve endings located in the aortic arch, which detect changes in blood pressure. When blood pressure increases, the baroreceptors send signals to the brain, specifically to the cardiovascular control center, which then activates the parasympathetic nervous system. The parasympathetic nervous system helps to decrease heart rate and blood pressure, promoting relaxation and reducing stress on the cardiovascular system. Therefore, increased activity by the parasympathetic nervous system is the correct answer.

The correct answer is the common iliac artery. The common iliac artery is a major blood vessel that branches off from the abdominal aorta and supplies blood to the pelvic organs and lower limbs. It divides into the internal iliac artery, which supplies the pelvic organs, and the external iliac artery, which continues down the leg as the femoral artery. Therefore, option 6, common iliac artery, is the correct identification for the labeled artery.

The structure labeled "3" in this question is the capsule. The capsule is the outermost layer of the kidney, which surrounds and protects the organ. It is a tough, fibrous membrane that helps maintain the shape and integrity of the kidney.

At a PO2 of 70mm Hg and normal temperature and pH, hemoglobin is more than 90 percent saturated. This means that more than 90 percent of the hemoglobin molecules are bound to oxygen.

The uvula is a structure that hangs down from the soft palate in the back of the mouth. It helps prevent food from entering the pharynx prematurely by blocking the opening between the oral cavity and the pharynx. When swallowing, the uvula moves upward and seals off the nasopharynx, preventing food and liquid from entering the nasal cavity. Therefore, the uvula plays a crucial role in preventing food from entering the pharynx too soon and ensures that it goes down the esophagus instead.