Anatomy Final Exam 3 Review

Excess secretion of growth hormone prior to puberty will cause gigantism. This is because growth hormone stimulates the growth of bones and tissues. When there is an overproduction of growth hormone, it leads to excessive growth and development of the body, resulting in gigantism. This condition is characterized by abnormally tall stature and enlarged body parts. It is important to note that gigantism occurs before the closure of the growth plates in the long bones, which happens during puberty.

The autonomic nervous system directly affects heart function by changing the heart rate and heart contractility. These changes are controlled by the sympathetic and parasympathetic branches of the autonomic nervous system. The sympathetic branch increases heart rate and contractility, while the parasympathetic branch decreases heart rate. Venous return, on the other hand, is not directly affected by the autonomic nervous system. Therefore, the correct answer is A and B but not C.

The hypothalamus is responsible for controlling the function of the anterior pituitary gland by releasing hormones. It acts as a bridge between the nervous and endocrine systems, regulating various bodily functions such as body temperature, hunger, thirst, and hormone production. The hypothalamus releases hormones that either stimulate or inhibit the release of specific hormones from the anterior pituitary gland, ultimately regulating the activity of other endocrine glands in the body.

The SA (sinoatrial) node is known as the primary pacemaker of the heart because it initiates the electrical impulses that regulate the heart's rhythm. Located in the right atrium, the SA node generates electrical signals that cause the atria to contract and send blood to the ventricles. These signals then travel to the AV (atrioventricular) node, which acts as a relay station, directing the impulses to the ventricles and causing them to contract. The other options, such as the medulla oblongata, pons, and thalamus, are not directly involved in the heart's pacemaker function.

B cells are responsible for humoral immunity. They are a type of white blood cell that produces and secretes antibodies, which are proteins that help in the immune response against pathogens. B cells are activated when they encounter an antigen, and they differentiate into plasma cells that produce large quantities of antibodies specific to that antigen. These antibodies then circulate in the body, binding to and neutralizing the pathogens. B cells also play a role in memory response, allowing for a quicker and more effective immune response upon subsequent exposure to the same antigen.

Iodine is often added to table salt to help the body make sufficient amounts of thyroxin. Thyroxin is a hormone produced by the thyroid gland that is essential for regulating metabolism and growth. Iodine is a necessary component for the synthesis of thyroxin, and without sufficient iodine, the body cannot produce enough thyroxin. Therefore, adding iodine to table salt ensures that individuals receive an adequate amount of iodine, which is crucial for the production of thyroxin.

In order for a lymphocyte to respond to an antigen, the antigen must bind to specific receptors on the lymphocyte membrane. This is because lymphocytes have specific receptors on their membrane called antigen receptors, which are responsible for recognizing and binding to specific antigens. Once the antigen binds to the receptor, it triggers a series of signaling events within the lymphocyte, leading to its activation and subsequent immune response against the antigen.

T cells are a type of white blood cell that play a crucial role in the immune system. The stem cells that give rise to T cells undergo maturation and differentiation in the thymus gland. The thymus is a specialized organ located in the chest, just above the heart. It is responsible for the development and education of T cells, ensuring that they can recognize and respond to specific pathogens while avoiding attacking the body's own cells. Therefore, the correct answer is the thymus.

When the vessel diameter decreases, it will result in vasoconstriction, which will reduce the blood flow to the tissue. Therefore, this change will not lead to increased blood flow to a tissue, making it the exception among the given options.

Protruding eyeballs, also known as exophthalmos, is a common symptom of hyperthyroidism. Hyperthyroidism is a condition where the thyroid gland produces an excess amount of thyroid hormones. This hormonal imbalance can cause various symptoms, including bulging eyes. The excessive production of thyroid hormones can cause inflammation and swelling of the tissues behind the eyes, leading to the appearance of protruding eyeballs. Therefore, hyperthyroidism is the likely indicator for protruding eye balls.

When a tissue generates high levels of carbon dioxide, it indicates that the tissue is metabolically active and in need of more oxygen. In response to this, the body increases blood flow to the tissue to deliver more oxygen and remove the excess carbon dioxide. Therefore, the correct answer is that more blood is delivered to the tissue.

If you have a hematocrit value of 30, it means that the percentage of red blood cells in your blood is lower than the normal range. A normal hematocrit value for men is typically between 38.8% and 50%, and for women, it is usually between 34.9% and 44.5%. Anemia refers to a condition where there is a decrease in the number of red blood cells or a decrease in the amount of hemoglobin in the blood. Therefore, having a hematocrit value of 30 indicates that you are anemic.

The blind spot in the retina occurs where the optic nerve attaches to the retina. This is because there are no photoreceptor cells (rods and cones) in this area, which are responsible for detecting light and creating visual signals. The optic nerve carries these signals from the retina to the brain for processing, so where it attaches to the retina, there is no visual information being transmitted, resulting in a blind spot.

Plasma cells are the cells responsible for the production of circulating antibodies. These cells are derived from B cells and are specialized to produce and secrete large amounts of antibodies. Plasma cells are crucial for the immune response as they help in neutralizing pathogens and toxins by producing specific antibodies that can recognize and bind to these foreign substances. This enables the immune system to eliminate the invaders and protect the body from infections.

The anterior pituitary is responsible for releasing HGH (human growth hormone). HGH plays a crucial role in growth, cell regeneration, and maintaining healthy body composition. It stimulates growth in children and adolescents and helps regulate metabolism in adults. The other options listed (posterior pituitary, thyroid, thymus, and adrenal gland) are not directly involved in the release of HGH.

Injecting EPO (erythropoietin) into a healthy body would be expected to result in polycythemia. EPO is a hormone that stimulates the production of red blood cells in the bone marrow. When injected, it increases the number of red blood cells in the body, leading to an increase in hematocrit and hemoglobin levels. This condition is known as polycythemia, which can cause thickening of the blood and potential complications such as blood clots.

The precapillary sphincter is responsible for regulating blood flow through a capillary. It is a ring of smooth muscle located at the entrance of a capillary bed. When the sphincter is relaxed, blood flows freely through the capillary bed. However, when the sphincter contracts, it constricts the entrance of the capillary bed, reducing blood flow. This allows for precise control of blood distribution to different tissues and organs based on their metabolic needs.

The P wave of the ECG corresponds to atrial depolarization. Depolarization refers to the electrical activation of the heart muscle cells, causing them to contract. In this case, the P wave represents the depolarization of the atria, which is the contraction of the atrial muscle. This is an important event in the cardiac cycle as it precedes the contraction of the ventricles and the pumping of blood into the rest of the body. Therefore, the correct answer is atrial depolarization.

During ventricular systole, the contraction of the ventricles causes an increase in pressure, which leads to the opening of the aortic valves. This allows the oxygenated blood to be pumped out of the left ventricle and into the aorta, which is then distributed to the rest of the body. The opening of the aortic valves is an important event during ventricular systole as it ensures the proper flow of blood and facilitates the circulation process.

When viewing an object close to you, your lens should be more rounded. This is because the lens needs to increase its curvature in order to focus the incoming light rays onto the retina, which is necessary for clear vision of nearby objects. A rounded lens helps to refract the light more effectively, allowing for sharper focus and better visual acuity.

The long-lasting plateau of the cardiac action potential is due to a prolonged calcium ion entry. Calcium ions play a crucial role in the contraction of cardiac muscle cells. During the plateau phase, the influx of calcium ions into the cells prolongs the depolarization, allowing for sustained contraction of the heart muscle. This prolonged calcium entry helps to maintain the plateau phase and ensures efficient pumping of blood by the heart.

Ganglion cells are the neuron type in the human retina that extends its axons toward the brain. These cells receive input from bipolar cells and amacrine cells, and their axons form the optic nerve, which transmits visual information from the retina to the brain. Horizontal cells, amacrine cells, bipolar cells, and photoreceptor cells (cones and rods) are all involved in the processing of visual information within the retina, but only ganglion cells are responsible for transmitting this information to the brain.

When the blood osmotic pressure at the capillary decreases, it means that there is a decrease in the concentration of proteins in the blood. Osmotic pressure is the force that draws fluid into the capillaries from the surrounding tissues. Proteins in the blood, such as albumin, play a crucial role in maintaining the osmotic pressure. When the concentration of proteins decreases, the osmotic pressure decreases as well, leading to a decrease in fluid reabsorption from the tissues into the capillaries. This can result in the accumulation of fluid in the tissues, causing edema.

The correct answer is B and C but not A. Lymph nodes act as a check station for cancer cells and monitor the contents of lymph by removing debris and pathogens. However, they do not produce antibodies from specialized T cells.

A capillary containing substantially fewer proteins than normal will have more water leaving the capillary. Proteins in the blood help to maintain the osmotic pressure, which prevents excessive water from leaving the capillaries. When there are fewer proteins, the osmotic pressure decreases, allowing more water to leave the capillary. This results in a higher hydrostatic pressure inside the capillary, less water entering the lymphatics, more ions leaving the capillary, and a lower hydrostatic pressure outside the capillary.

Steroid hormones are unable to diffuse through the cell membrane, so they bind to intracellular receptors instead. This allows them to initiate a signaling cascade within the cell, functioning by activating cAMP (cyclic adenosine monophosphate). By binding to intracellular receptors, steroid hormones are able to regulate gene expression and influence various cellular processes.

If peripheral resistance does not change, causing higher blood pressure will cause greater blood flow. This is because blood pressure is directly related to the force with which blood is pumped through the blood vessels. When blood pressure increases, it creates a greater force that pushes blood through the vessels, resulting in a higher blood flow.

According to Starling's law of the heart, the cardiac output is directly related to the venous return. This means that as the amount of blood returning to the heart from the veins increases, the heart will pump out a greater volume of blood. This relationship is important for maintaining proper blood flow and ensuring that the body's tissues receive an adequate supply of oxygen and nutrients.

When the stereocilia are bent towards the tallest ones, it causes the opening of ion channels in the hair cell. This allows positive ions to flow into the cell, leading to a change in the cell's electrical charge. This change in charge is known as depolarization, which is the correct answer.

The ciliary muscle helps to control the shape of the lens. When the ciliary muscle contracts, it causes the lens to become more rounded, allowing the eye to focus on near objects. When the ciliary muscle relaxes, the lens becomes flatter, enabling the eye to focus on distant objects. By adjusting the shape of the lens, the ciliary muscle plays a crucial role in the eye's ability to focus and maintain clear vision at varying distances.

The question states that the heart rate increases and stroke volume decreases. Normally, an increase in heart rate would lead to an increase in cardiac output, while a decrease in stroke volume would lead to a decrease in cardiac output. However, since both variables are changing in opposite directions, it is uncertain how they would affect the overall cardiac output. Therefore, the change in cardiac output in this scenario is uncertain.

The organ of Corti is the structure that separates the cochlear duct from the tympanic duct. It is located in the cochlea of the inner ear and contains sensory hair cells that are responsible for converting sound vibrations into electrical signals that can be interpreted by the brain. The tectorial membrane, tympanic membrane, vestibular duct, and basilar membrane are all important components of the inner ear, but they do not specifically separate the cochlear duct from the tympanic duct like the organ of Corti does.

When a patient has conjunctivitis, the infection primarily affects the superficial epithelium of the eye. The superficial epithelium is the outermost layer of cells on the surface of the eye. Conjunctivitis, also known as pink eye, is an inflammation of the conjunctiva, which is the thin, transparent layer that covers the white part of the eye and the inner surface of the eyelids. The infection can cause redness, itching, discharge, and swelling of the eye. Therefore, the superficial epithelium is the correct answer as it is the part of the eye that is primarily infected in conjunctivitis.