Vnsg Anatomy & Physiology Study Guide

All of the options listed in the question are organs of the nervous system. The brain, nerves, and spinal cord are all essential components of the nervous system. The brain is the control center of the body, nerves transmit signals throughout the body, and the spinal cord serves as a pathway for these signals. Therefore, all of the options provided are correct and are considered organs of the nervous system.

The word "anatomy" is derived from 2 Greek words meaning "a cutting up." This suggests that anatomy involves the study of the structure and organization of living organisms by dissecting and examining their parts. Physiology is the study of how living organisms function, while homeostasis refers to the body's ability to maintain a stable internal environment. Dissection is the act of cutting apart or separating tissues for examination. Therefore, the correct answer is anatomy.

The immunity that is passed from mother to fetus is an example of natural passive immunity. During pregnancy, antibodies are transferred from the mother to the fetus through the placenta. This provides temporary protection to the newborn against certain diseases. It is considered natural because it occurs naturally during the normal course of pregnancy, and it is passive because the fetus does not actively produce the antibodies but rather receives them from the mother.

The Golgi apparatus is responsible for chemically processing molecules in the cell. It consists of flattened sacs called cisternae, which function to modify, package, and sort proteins and lipids that are synthesized in the endoplasmic reticulum. These processed molecules are then transported to their final destinations within the cell or outside of it. The Golgi apparatus plays a crucial role in cellular secretion and intracellular transport, making it the correct answer in this case.

The primary function of the integumentary system is to protect the underlying structures of the body. This includes protecting the internal organs, muscles, and bones from external factors such as physical trauma, pathogens, and harmful substances. The skin acts as a barrier, preventing these external elements from entering the body and causing damage. Additionally, the integumentary system also helps in maintaining homeostasis by regulating body temperature through processes like sweating and shivering. It also plays a role in the synthesis of vitamin D, which is important for calcium absorption and bone health.

The thymus gland is not located in the skull. It is a part of the lymphatic system and is situated in the upper chest, behind the sternum. The thymus gland plays a crucial role in the development and maturation of T-lymphocytes, which are important for the immune system. It produces hormones that help regulate the immune response, but it is not located in the skull like the other options mentioned.

The average weight of the skin in most adults is about 20 pounds. The skin is the largest organ in the body and serves as a protective barrier. It is composed of several layers and contains various tissues, including fat, muscle, and connective tissue. The weight of the skin can vary depending on factors such as body size, age, and overall health. However, 20 pounds is a commonly accepted estimate for the weight of the skin in adults.

A burn involving both the epidermis and the upper layers of the dermis is called a second-degree burn. This type of burn is characterized by redness, swelling, blisters, and pain. The epidermis and the upper layers of the dermis are affected, but the burn does not extend into the deeper layers of the skin. Healing time for second-degree burns is usually longer than first-degree burns, and scarring may occur. Immediate medical attention and proper treatment are necessary for second-degree burns to prevent infection and promote healing.

The atomic number of an atom is determined by the number of protons it has. In this case, the atom has 16 protons, so the atomic number is 16.

The term "posterior" refers to the back side of the body, while "dorsal" refers to the upper side or back. Since humans walk in an upright position, their back side is also their upper side, making "posterior" and "dorsal" interchangeable terms. Therefore, the correct answer is "posterior and dorsal."

Abduction is the correct answer because it refers to the movement of a body part away from the midline of the body. This movement is typically seen when a limb is moved away from the center of the body, such as when lifting the arm to the side or spreading the legs apart. Adduction, on the other hand, refers to the movement of a body part towards the midline of the body. Rotation refers to the movement of a body part around its axis, and pronation refers to the rotation of the forearm so that the palm faces downwards.

If an atom has 20 protons and 18 electrons, it means that there are more protons than electrons. Since protons have a positive charge and electrons have a negative charge, the atom will have an overall positive charge. The difference between the number of protons and electrons is 2, so the atom will have a plus 2 charge.

An organ is composed of 2 or more kinds of tissues, which means it is made up of different types of cells working together to perform specific functions. Organs are also grouped into systems, such as the respiratory system or digestive system, where they work together to carry out more complex functions necessary for the overall functioning of the body. Therefore, all of the given statements are true and accurately describe an organ.

The thoracic duct is responsible for returning lymph to the blood. It is the largest lymphatic vessel in the body and drains lymph from the lower body, left side of the head and neck, and the left arm. The thoracic duct then empties into the left subclavian vein, which is connected to the superior vena cava. This allows the lymph, which contains waste products and immune cells, to be returned to the bloodstream for circulation throughout the body. The aorta and inferior vena cava are not involved in the return of lymph to the blood.

Lymph vessels are not a part of the cardiovascular system. The cardiovascular system consists of the heart and blood vessels, which are responsible for the circulation of blood throughout the body. Lymph vessels, on the other hand, are a part of the lymphatic system, which is a separate system that helps in the transportation of lymph fluid and immune cells.

The cell membrane acts as an "identification tag" for the cell by containing specific molecules, such as proteins and carbohydrates, that can be recognized by other cells and molecules in the body. This allows for cell recognition and communication, as well as the ability to distinguish between self and non-self cells. The cell membrane also plays a role in cell signaling and transport of molecules in and out of the cell.

Urine is produced in the kidneys and then travels through the ureters, which are tubes that connect the kidneys to the bladder. From the bladder, urine is then expelled through the urethra. Therefore, the correct sequence is kidney, ureter, bladder, urethra.

The muscle attachment to the more movable bone is called the insertion. This is because the insertion refers to the point where the muscle attaches to the bone that experiences the greatest movement when the muscle contracts. The origin, on the other hand, refers to the point where the muscle attaches to the less movable bone. Tendon is the fibrous tissue that connects muscle to bone, and bursae are small fluid-filled sacs that reduce friction between tissues.

Electrons are subatomic particles that are found in orbitals around the nucleus of an atom. They have a negative charge and are responsible for the chemical behavior of atoms. Neutrons and protons are also found in the nucleus of an atom, but they do not exist in orbitals like electrons do. Therefore, the correct answer is electron.

The muscle attachment to the more stationary bone is called the origin. This is because the origin is the point where the muscle attaches to the bone that remains relatively fixed during movement. The origin provides stability and a starting point for muscle contraction, allowing the muscle to generate force and move the more movable bone.

Ribosomes are the organelles responsible for protein synthesis in the cell. They are composed of RNA and proteins and are found either floating freely in the cytoplasm or attached to the endoplasmic reticulum. Ribosomes read the genetic information in the form of messenger RNA (mRNA) and use it to assemble amino acids into proteins through a process called translation. Therefore, ribosomes are considered the "protein factories" of the cell. Mitochondria are responsible for energy production, Golgi apparatus for protein modification and packaging, and centrioles for cell division, so they are not the primary organelles involved in protein synthesis.

An antigen can be a toxin, a protein on a cancer cell membrane, or a protein on a bacterial cell membrane. This means that all of these options are correct and can be considered as antigens. Antigens are substances that stimulate an immune response in the body, leading to the production of antibodies. Toxins, as well as proteins on cancer and bacterial cell membranes, can trigger an immune response and be recognized as antigens by the immune system. Therefore, all of the given options are valid examples of antigens.

A proton is a subatomic particle that carries a positive electrical charge. It is located in the nucleus of an atom and contributes to the atom's atomic number and atomic mass. However, it does not carry a negative electrical charge.

The pulse can be felt only in arteries because arteries carry oxygenated blood away from the heart to the rest of the body. When the heart beats, it creates a pressure wave that travels through the arteries, causing them to expand and contract. This expansion and contraction can be felt as a pulse in certain areas of the body, such as the wrist, neck, or groin, where arteries are close to the surface. Veins, on the other hand, carry deoxygenated blood back to the heart and do not have the same strong pulsation as arteries.

Voluntary movement refers to the conscious control and coordination of muscle contractions to produce purposeful movement. Skeletal muscles are the only muscles in the body that are under voluntary control. Cardiac muscles are found in the heart and are responsible for its involuntary contractions, while smooth muscles are found in various organs and perform involuntary movements. Therefore, the correct answer is skeletal muscle contracts, as voluntary movement occurs when skeletal muscles contract.

The correct answer is dorsal and ventral. The body is divided into two major cavities: the dorsal cavity, which is located along the posterior side of the body and contains the cranial and spinal cavities, and the ventral cavity, which is located along the anterior side of the body and contains the thoracic and abdominal cavities. These two cavities are important for protecting and housing vital organs and systems within the body.

Enamel is the hard, outermost layer of the tooth that covers the crown, which is the visible part of the tooth above the gum line. It is the hardest substance in the human body and protects the underlying dentin and pulp of the tooth. Enamel is not found in the root or neck of the tooth, making the correct answer "crown of the tooth."

Salivary glands are not part of the endocrine system because they do not secrete hormones directly into the bloodstream. Instead, they secrete saliva into the mouth through ducts. The endocrine system consists of glands that release hormones directly into the bloodstream to regulate various bodily functions. The pituitary gland, thyroid gland, and hypothalamus are all examples of endocrine glands that secrete hormones.

Epithelial membranes are composed of epithelial tissue and connective tissue. They line body cavities and cover the body's external surface. Cutaneous, serous, and mucous membranes are all examples of epithelial membranes. However, synovial membranes are not considered epithelial membranes. Synovial membranes are found in joints and are composed of connective tissue. They secrete synovial fluid, which lubricates the joints and reduces friction.

Ionic bonds are formed between atoms of opposite charge, resulting in the production of ions. These ions are able to dissolve easily in water due to the polar nature of water molecules. Therefore, all of the given options are correct explanations for ionic bonds.

The lymphatic system includes lymph nodes. Lymph nodes are small, bean-shaped structures that are part of the immune system. They are responsible for filtering lymph fluid and trapping harmful substances such as bacteria and viruses. Lymph nodes contain white blood cells called lymphocytes, which help fight off infections and diseases. Therefore, the correct answer is lymph nodes.

The liver is not part of the lymphatic system because it does not produce or store lymphocytes, which are the white blood cells responsible for immune responses. The liver's main functions include detoxification, metabolism, and production of bile. In contrast, the spleen, thymus, and tonsils are all organs that play important roles in the lymphatic system. The spleen filters blood and helps fight infections, the thymus produces and matures T-cells, and the tonsils help trap and kill bacteria and other pathogens.

Cholesterol molecules stabilize the cell membrane and prevent it from breaking easily. Cholesterol is a lipid molecule that is interspersed between the phospholipids in the cell membrane. It helps to maintain the fluidity and flexibility of the membrane, making it less prone to rupture. Additionally, cholesterol molecules also play a role in regulating the permeability of the cell membrane, ensuring that only certain molecules can pass through. Therefore, all of the above options, including phospholipid molecules and protein molecules, contribute to stabilizing the cell membrane, but cholesterol molecules specifically play a crucial role in this process.

The stomach is an organ that is part of the gastrointestinal tract. It is responsible for breaking down food through the secretion of digestive enzymes and acids. It plays a crucial role in the digestion and absorption of nutrients. The liver and pancreas are also part of the gastrointestinal tract, but they are not the correct answer to this question. The liver produces bile, which aids in the digestion and absorption of fats, while the pancreas produces digestive enzymes and hormones that regulate blood sugar levels.

Smooth muscle is found in the walls of blood vessels and the digestive tract, and its contraction helps in maintaining blood pressure and moving food through the digestive system. However, smooth muscle is not responsible for the movement of bones in the skeletal system. Therefore, when smooth muscle contracts, the bones of the skeletal system do not move.

The salivary gland is an accessory organ of the digestive system because it produces saliva, which aids in the digestion of food. Saliva contains enzymes that break down carbohydrates and lubricates food to facilitate swallowing. While the stomach and small intestine are also important organs in the digestive system, they are not considered accessory organs as they play a more direct role in the digestion and absorption of nutrients.

The upper respiratory tract consists of the nose, pharynx, and larynx. The trachea, on the other hand, is part of the lower respiratory tract. It is the tube that connects the larynx to the bronchi, allowing air to pass into the lungs. Therefore, the trachea is not included in the upper respiratory tract.

The correct answer is ureter. The ureter is a tube that carries urine from the kidney to the bladder. It is responsible for transporting the urine, which is produced in the kidney, to the bladder for storage and eventual elimination from the body. The urethra, on the other hand, is the tube that carries urine from the bladder to the outside of the body. Bronchioles are small air passages in the lungs, not involved in the transportation of urine. Therefore, the correct answer is ureter.

The second energy level of an atom has four orbitals, which means it can accommodate a maximum of eight electrons. This is because each orbital can hold a maximum of two electrons. Additionally, the second energy level is actually a higher energy level than the first energy level, so the correct answer is "both a and b above".

The formula for oxygen gas, O2, indicates that it is made up of two atoms of oxygen. This implies that it is a molecule, as molecules are formed when two or more atoms chemically bond together. Therefore, the correct answer is both a and b above, as oxygen gas is both made up of two atoms of oxygen and is a molecule.

The vas deferens is an accessory organ of the male reproductive system. It is a tube that carries sperm from the testes to the urethra during ejaculation. The penis is the external genitalia that is involved in sexual intercourse and urination. The testes are the primary reproductive organs that produce sperm and testosterone. The scrotum is a sac-like structure that houses the testes and helps regulate their temperature. Therefore, the vas deferens is the correct answer as it specifically refers to an accessory organ involved in the transportation of sperm.

The correct answer is "ductless glands." The glands in the endocrine system are referred to as ductless glands because they do not have ducts or tubes to transport their secretions. Instead, they release hormones directly into the bloodstream, which then carry the hormones to target cells or organs throughout the body. This is in contrast to exocrine glands, which have ducts to transport their secretions to specific locations, such as sweat glands or salivary glands. The term "hormones" refers to the chemical messengers produced by the endocrine glands, rather than the glands themselves.

The thymus gland is not located in the neck. It is a small gland located in the upper chest, behind the sternum. The thymus gland plays a crucial role in the development and maturation of T-cells, which are important for the immune system. Unlike the thyroid gland and parathyroid glands, which are located in the neck, the thymus gland is situated in the chest region.

The lymphatic system is not involved in the movement of liquid waste to the kidney. The lymphatic system primarily functions in the transportation of lymph, a fluid containing white blood cells, throughout the body. It helps in the functioning of the immune system by filtering out harmful substances and producing immune cells. The movement of fat-related materials from the digestive system to the blood is also facilitated by the lymphatic system. However, the lymphatic system does not play a role in the movement of liquid waste to the kidney, which is primarily carried out by the urinary system.

This is an example of artificial passive immunity because the person is being given pre-formed antibodies (gamma globulin) to protect against hepatitis, rather than producing their own antibodies through active immune response.

An electron contributes to the atom's atomic number because the atomic number of an atom is determined by the number of protons in its nucleus, and electrons balance out the positive charge of the protons. Therefore, the number of electrons in an atom directly affects its atomic number.

The apical beat refers to the pulsation of the apex of the heart, which can be felt during a physical examination. The correct answer states that the apical beat can be heard in the space between the fifth and sixth rib, as well as on a line even with the midpoint of the left clavicle. This means that the pulsation can be detected in both locations, indicating that both options B and C are correct.

The tricuspid valve is located between the right atrium and right ventricle. This valve ensures that blood flows in only one direction, preventing backflow from the ventricle to the atrium. When the right atrium contracts, the tricuspid valve opens, allowing blood to flow into the right ventricle. When the right ventricle contracts, the valve closes, preventing blood from flowing back into the atrium. The blood then exits the right ventricle through the pulmonary artery, which carries it to the lungs for oxygenation.

The main function of the respiratory system is the exchange of oxygen and carbon dioxide. This exchange occurs in the alveoli, which are tiny air sacs located in the lungs. Oxygen from the inhaled air enters the bloodstream through the thin walls of the alveoli, while carbon dioxide, a waste product, is removed from the bloodstream and exhaled through the alveoli. The alveoli provide a large surface area for efficient gas exchange due to their numerous and small size, making them the correct answer.

The nervous system is responsible for integrating and controlling body functions. It coordinates the activities of different body systems and helps maintain homeostasis. However, the regulation of the immune response is not a function of the nervous system. The immune system is a separate system that is responsible for defending the body against pathogens and foreign substances. While the nervous system can influence the immune response through neurotransmitters and hormones, it does not directly regulate it.

The mediastinum is a part of the ventral cavity. The ventral cavity is located in the front of the body and is divided into two main sections: the thoracic cavity and the abdominopelvic cavity. The mediastinum is a central compartment within the thoracic cavity, which contains various structures such as the heart, major blood vessels, esophagus, and trachea. Therefore, the correct answer is ventral cavity.

Blood and lymph capillaries share several common characteristics, such as being microscopic and having a layer of endothelium. However, the statement that they have tight-fitting cells in the endothelial layer is not true for both blood and lymph capillaries. This characteristic is specific to blood capillaries, as they have tight junctions between endothelial cells that restrict the passage of substances. In contrast, lymph capillaries have looser junctions between endothelial cells, allowing for the entry of larger molecules and cells. Therefore, the correct answer is that tight-fitting cells in the endothelial layer is not a common characteristic shared by blood and lymph capillaries.

Receiving a flu shot is an example of artificial active immunity because it involves the administration of a vaccine that contains weakened or inactivated flu viruses. This stimulates the immune system to produce an immune response, including the production of antibodies, without causing the actual disease. The individual's immune system then "remembers" the specific antigens from the vaccine, allowing it to mount a rapid and effective immune response if exposed to the actual flu virus in the future.

The endoplasmic reticulum is the correct answer because it consists of a network of canals that wind through the cytoplasm. These canals, also known as cisternae, are interconnected and form a complex network throughout the cell. The endoplasmic reticulum plays a crucial role in various cellular processes, including protein synthesis, lipid metabolism, and calcium storage. It is involved in the transport of molecules within the cell and provides a large surface area for chemical reactions to occur.

The correct answer is transportation of material. The cardiovascular system is responsible for transporting oxygen, nutrients, hormones, and waste products throughout the body. It consists of the heart, blood vessels, and blood, which work together to ensure that essential substances are delivered to cells and waste products are removed. This system plays a crucial role in maintaining homeostasis and supporting the overall function of the body.

The subcutaneous layer of skin, also known as the hypodermis, is responsible for storing fat that can be used for food, protecting the underlying tissue by acting as a "shock absorber," and helping the body in temperature regulation. However, it does not produce melanin to protect the skin from the ultraviolet rays of the sun. Melanin is produced by cells called melanocytes, which are located in the epidermis, the outermost layer of the skin. The subcutaneous layer is located beneath the dermis and serves primarily as an insulating layer.

The plasma membrane of a cell is composed of phospholipid molecules, cholesterol molecules, and protein molecules. Phospholipids make up the majority of the membrane structure and form a lipid bilayer, providing a barrier that controls the movement of substances in and out of the cell. Cholesterol molecules are interspersed within the phospholipids, contributing to the fluidity and stability of the membrane. Proteins are embedded in the phospholipid bilayer and have various functions, including transport of molecules, cell signaling, and structural support. Therefore, all of these components are essential for the structure and function of the plasma membrane.

The plasma membrane contains protein molecules that serve as receptors for other molecules. These receptors play a crucial role in cell signaling and communication by binding to specific molecules and initiating a cellular response. Phospholipid molecules and cholesterol molecules are also components of the plasma membrane, but they do not serve as receptors for other molecules. Therefore, the correct answer is protein molecules.

The skeletal system is composed of bones, cartilage, and ligaments, which all play a crucial role in supporting and protecting the body. Tendons, however, are not part of the skeletal system. Tendons are tough bands of fibrous connective tissue that connect muscles to bones, allowing for movement and transmitting the force generated by the muscles to the bones. While tendons are closely related to the skeletal system, they are not considered part of it.

Neutrons do not contribute to an atom's atomic number because atomic number is determined by the number of protons in the nucleus. Neutrons, on the other hand, contribute to the atom's atomic mass because they have mass but no electrical charge. Neutrons are located in the nucleus of the atom along with protons.

Cardiac output refers to the volume of blood pumped per minute. It can be measured either as the volume of blood pumped from both ventricles or from one ventricle per minute. Additionally, the average cardiac output in an adult is approximately 5 liters. Therefore, the correct answer is both b and c above.

The membrane covering the lungs is called the visceral pleura. The term "visceral" refers to the organs, in this case, the lungs, and "pleura" refers to the serous membrane that lines the thoracic cavity and covers the lungs. The visceral pleura is in direct contact with the lungs, providing a protective covering and allowing for smooth movement during breathing. The other options, visceral peritoneum, parietal pleura, and parietal peritoneum, refer to different membranes that cover other organs or line different body cavities.

The atomic number of an atom is equal to the number of protons. This is because the atomic number represents the unique identity of an element, and the number of protons determines the element's identity. Electrons can vary in number and are found in the electron cloud surrounding the nucleus, while neutrons contribute to the mass of the atom but do not affect its identity.

The urethra is the correct answer because it is a structure that is present in both the reproductive and urinary systems. In males, the urethra functions as a passageway for both urine and semen, while in females, it serves as a passage for urine only. Therefore, the urethra is the only option that is part of both systems, making it the correct answer.

The thyroid is not part of the lymphatic system. The lymphatic system is a network of vessels, organs, and lymph nodes that helps to remove waste, toxins, and other substances from the body. The thymus, spleen, and lymph nodes are all part of the lymphatic system and play important roles in immune function and the production of white blood cells. However, the thyroid is a gland located in the neck that produces hormones and is not directly involved in the lymphatic system.

The correct answer is visceral peritoneum. The peritoneum is a membrane that lines the abdominal cavity and covers the organs within it. The visceral peritoneum specifically refers to the portion of the peritoneum that covers the organs directly. The parietal peritoneum, on the other hand, lines the abdominal cavity itself. The options "visceral pleura" and "parietal pleura" are incorrect because they refer to the membranes that cover the lungs, not the organs of the abdomen.

Covalent bonds are formed when electrons are shared between atoms. In a covalent bond, two atoms share one or more pairs of electrons, resulting in a stable arrangement of electrons for both atoms. This sharing of electrons allows the atoms to achieve a full outer electron shell, similar to the noble gases. Covalent bonds are typically found between nonmetal atoms and are strong and stable. They do not dissociate in water, as they are not ionic bonds that involve the complete transfer of electrons between atoms. The statement "both a and c above" is incorrect because covalent bonds do not involve atoms of opposite charge.

The correct answer is "all of the above glands are located in the abdomen." This means that all three options mentioned in the question (adrenal gland, pancreas, and ovaries) are located in the abdomen.

The "rule of nines" is a method of determining the severity of burns. It consists of 11 areas of the body, each covering about 9% of the body. This method is used to estimate the extent of burns and helps in determining the amount of fluids needed for resuscitation and the urgency of medical intervention.

This statement describes natural active immunity, which occurs when a person's immune system develops a response to a pathogen after being exposed to it. In the case of measles, once a person has had the infection, their immune system produces antibodies that protect them from getting the measles again in the future.

The urinary system is responsible for filtering waste products from the blood, such as urea and excess water, and excreting them in the form of urine. However, it does not clean the blood of digestive waste products. These waste products are processed and eliminated by the digestive system, specifically through the process of digestion and absorption in the gastrointestinal tract. Therefore, the urinary system is not involved in cleaning the blood of digestive waste products.

The ventricles are actually called discharging chambers and pump blood into the arteries. However, they do not have thinner walls than the atria. The atria have thinner walls compared to the ventricles.

Lysosomes are the organelles that act as the "digestive bags" of the cell. They contain digestive enzymes that break down waste materials, cellular debris, and foreign substances. This process, known as autophagy, helps in recycling and eliminating unwanted components within the cell. Lysosomes also play a crucial role in the digestion of macromolecules such as proteins, lipids, and carbohydrates. They are responsible for maintaining cellular homeostasis and are essential for overall cell function and health.

The correct answer is "they contain continually circulating fluid." This is because blood vessels contain blood, which circulates throughout the body, while lymph vessels contain lymph, which flows in only one direction towards the heart. Therefore, the statement that blood and lymph vessels contain continually circulating fluid is not accurate.

The lining of the blood vessels is not a mucous membrane because mucous membranes are moist and secrete mucus to protect and lubricate the surfaces they line. The lining of the blood vessels, known as the endothelium, does not secrete mucus and does not have the same protective functions as mucous membranes.

Organic compounds must contain carbon atoms. Oxygen, carbon-oxygen bonds, and hydrogen-oxygen bonds are not exclusive requirements for organic compounds. While many organic compounds do contain oxygen and/or carbon-oxygen or hydrogen-oxygen bonds, it is not necessary for all organic compounds to have these elements or bonds. Therefore, the correct answer is "none of the above."

Smooth muscles, also known as visceral muscles, are found in the walls of organs and structures such as the digestive tract, blood vessels, and respiratory system. Unlike skeletal muscles, smooth muscles are not under voluntary control. Cardiac muscles are a specific type of muscle found in the heart, while voluntary muscles refer to skeletal muscles that are under conscious control. Therefore, the correct alternative name for smooth muscles is visceral muscle.

Dentin is a hard, calcified tissue that forms the majority of the tooth structure. It is found in the root, crown, and neck of the tooth. The neck of the tooth is the area where the crown and root meet. Therefore, the correct answer is "all of the above" because dentin is present in all these regions of the tooth.

The respiratory membrane refers to the lining of the alveoli, which are the tiny air sacs in the lungs where gas exchange occurs. It is made up of a thin layer of cells that allow for the diffusion of oxygen into the bloodstream and the removal of carbon dioxide from the bloodstream. The term "respiratory mucosa" is another way to describe this lining. Therefore, the correct answer is that the respiratory membrane is another term for the respiratory mucosa.

Both the neutron and the proton are subatomic particles found in the nucleus of an atom. The neutron has no charge, while the proton has a positive charge. Therefore, the correct answer is both b and c above, as both the neutron and the proton are present in the nucleus of an atom.

The respiratory mucosa lines most of the air distribution tubes in the respiratory system. This includes the nasal cavity, trachea, bronchi, and bronchioles. The mucosa is made up of a layer of epithelial cells that help to moisten and protect the airways. It also contains mucus-producing cells and cilia, which help to trap and remove foreign particles and microorganisms. By lining the air distribution tubes, the respiratory mucosa plays a crucial role in maintaining the health and functionality of the respiratory system.

The correct answer is parietal pleura. The parietal pleura is the membrane that lines the interior of the thoracic cavity. It covers the walls of the chest and diaphragm, and it plays a crucial role in protecting and lubricating the lungs during respiration. The visceral pleura, on the other hand, covers the surface of the lungs, while the visceral peritoneum lines the abdominal organs, and the parietal peritoneum lines the abdominal cavity.

The ovaries are the primary reproductive organs in females, responsible for producing eggs and releasing hormones such as estrogen and progesterone. They play a crucial role in the menstrual cycle and fertility. The fallopian tubes are responsible for transporting eggs from the ovaries to the uterus. The uterus is where a fertilized egg implants and develops into a fetus. Mammary glands are accessory organs involved in the production and secretion of milk after childbirth. Therefore, the structure that is not an accessory organ of the female reproductive system is the ovaries.

The integumentary system is made up of various accessory structures that support its functions. These structures include hair, nails, and glands, but the skin itself is not considered an accessory structure. The skin is the main organ of the integumentary system and serves as a protective barrier, regulating body temperature, and housing sensory receptors. Therefore, the correct answer is skin.

The statement "receive blood from arteries returning to the heart" is not true of the atria. The atria receive blood from veins, not arteries.