HESI A2 Anatomy and Physiology Practice Test

The digestive tract performs all of the above functions except for performing gas exchange, which is a function of the respiratory system. Chemical digestion by the digestive tract enzymatically breaks down food. Nutrients are absorbed into the blood in the small intestine. Then, unabsorbed waste is eliminated from the large intestine through the anus.

Homeostasis refers to how the body maintains a stable internal environment despite changes internally and externally. ‘Homeo’ refers to sameness while and ‘stasis’ refers to equilibrium. The process whereby the body breaks down glucose to make energy to fuel other cellular processes is cellular respiration. The process by which the body minimizes and responses to infection by microorganisms is immunity. The concept describing how the body maintains its genetic composition despite different cells having different functions is phenotypic variation.

The endocrine system of the body manufactures hormones in specific glands. Each gland then secretes specific hormones into the bloodstream where they are disseminated throughout the body. Each hormone stimulates certain cells to perform certain actions. Hormones are signaling molecules. The immune system, specifically the humoral immune response, defends the body through the use of antibodies. The muscular system produces movement by contraction upon nervous stimulation. The cardiovascular system maintains blood flow through the use of the heart muscle.

The term anterior refers to a body part being located toward the front of the body. The term posterior refers to a body part being located toward the back of the body. The term lateral refers to a body part being located away from the body’s midline. The term superior refers to something being located toward the top (head) of the body.

The large intestine within the human digestive system houses bacteria that synthesize vitamin K. The liver, lungs, and gall bladder are not involved in vitamin K production. The liver performs a variety of bodily functions including storing glycogen, detoxifying toxins, and synthesizing bile that is then stored in the gall bladder. The gall bladder then secretes bile into the small intestine when needed to emulsify fats for digestion. The lungs are the site of gas exchange between the body and the air.

While thin in thickness, the skin is considered an organ and is therefore the largest in the body because of its great surface area. The skin is an important part of the integumentary system. The small intestine and stomach are both significant organs of the digestive system, but neither are the largest organ of the body. The small intestine where digestion and nutrient absorption occurs is the longest part of the digestive system, while the large intestine is the largest part of the digestive system. The femur is the largest bone in the body, but is not the largest organ.

Parenchyma is the functional tissue of an organ. The specific type of science that is the study of tissues is histology. Biology is the study of life in general, and histology, anatomy, and physiology are all different subdisciplines within biology. Anatomy is the study of the various structures of the body and their locations. Physiology is the study of how various parts of the body function.

Hemopoiesis refers to blood cell formation, including both red blood cells and white blood cells. Hematopoietic stem cells are found in the bone marrow and ultimately give rise to all types of blood cells. Erythropoiesis specifically refers to the process which produces erythrocytes (red blood cells). The destruction of red blood cell is called hemolysis. The destruction of white blood cells may result from several different causes and doesn’t have one specific name.

Keratin is a fibrous structural protein and is the key structural component of hair, nails, and the outer layer of human skin. It is not found in teeth. Dentin is the main structural component of teeth.

Muscle cells are also called muscle fibers. Each muscle cell contains many myofibrils, each of which are made up of sarcomeres. A sarcomere is a segment of a myofibril that contains actin and myosin that slide across each other, leading to muscle contraction.

The vastus lateralis muscle is a voluntary muscle located on the lateral side of the thigh and is the largest muscle of the quadriceps. A person with a torn vastus lateralis muscle will most likely need a cane or crutches to assist in walking. An arm sling would be appropriate for someone with a shoulder or arm injury. A rib support brace may be appropriate for someone with a chest or abdominal injury. A neck brace may be appropriate for someone with a neck injury.

The diaphysis is the shaft of a long bone while the epiphysis is the part at each end of a long bone where bone growth in length occurs. An osteoclast is a bone cell type that breaks down bone cell tissue, while an osteoblast is a bone cell type that forms new bone tissue.

The medulla oblongata is the lower part of the brain stem and is responsible for regulating basic vital functions, including respiration and heart rate. The cerebellum is responsible for muscular coordination and balance. The cerebrum is responsible for sensory interpretation, thinking, and personality. The thalamus (part of the diencephalon) is responsible for receiving incoming sensory information and routing it to the right part of the cerebrum.

Simple reflexes, known also as spinal reflexes, travel through the spinal cord only, and do not reach the brain.

Estrogen serves to thicken the endometrium in preparation for pregnancy, in addition to other functions. Progesterone also plays a role in endometrium development, counterbalancing the effects of estrogen. Luteinizing hormone triggers the release of the egg from the ovary. Oxytocin stimulates the lactation of breast milk. Fertilization happens when a sperm interacts with an egg (usually in the oviduct) and is not hormonally induced.

The ureters are the structures that allow urine to flow from the kidneys to the bladder. The urethra delivers urine from the bladder to body’s exterior during urination. A proximal tubule and a distal tubule are both components of a nephron. A nephron is the functional unit of the kidney where filtration actually occurs.

The gallbladder’s function is to store bile, but the digestive system continues to produce bile and to digest fat without it. However, one must limit the amount of fat intake at one time). Humans cannot survive without a pancreas, a liver, or lungs.

The nervous system controls motor impulses. The other choices are all roles of cortisol, a hormone released during stress from the adrenal cortex.

Thirty one pairs of spinal nerves exit the spinal cord. There are 7 cervical vertebrae and 12 thoracic vertebrae. In an adult, there are 24 individual vertebrae in addition to the sacrum and the coccyx, each of which are composed of multiple fused vertebrae.

Cilia are hair-like extensions that move substances over a cell’s surface. Each Golgi apparatus packages proteins from the rough endoplasmic reticulum into vesicles for transport to other parts of the cell or for secretion. The centriole is the organelle in a eukaryotic cell that organizes and guides chromosomal movement during cellular reproduction. Mitochondria are where ATP is made by cellular respiration.

Cyclic adenosine monophosphate (cAMP) serves as a secondary messenger inside of a cell. It is made from ATP by the enzyme adenylate cyclase, which is located on the inner side of the cell membrane. Adenylate cyclase activity is controlled by hormonal signaling. Thus, a hormone is secreted by an endocrine gland and binds to a receptor on a target cell. This binding influences adenylate cyclase activity, which then influences cAMP levels inside the cell. The change in cAMP levels inside the cell affect the activity of specific enzymes. Thus, cAMP is not part of the cell membrane, does not provide energy for the cell, nor is it an endocrine hormone.

The dendrites receive signals and transmit them toward the cell body of the neuron while an axon transmits signals away from the cell body. Typically, each neuron has multiple dendrites, one cell body, and one axon. Filaments are part of muscle cells, not neurons.

The pectoralis major muscle is located in the chest area. Some muscles in the back include the trapezius, the rhomboids (major and minor) and the latissimus dorsi. Some muscles in the feet include the dorsal muscles (extensor digitorum brevis and the extensor hallucis brevis) and various plantar muscles (flexor digitorum brevis and quadratus plantae) The buttocks muscles include the gluteus maximus, the gluteus minimus, and the gluteus medius.

Estrogen is a steroid hormone. Insulin and calcitonin are peptide hormones. Adrenaline is an amine hormone.

Blood calcium homeostasis is regulated by parathyroid hormone (made by the parathyroid) and calcitonin (made by the thyroid). Parathyroid hormone works to increase blood calcium levels when low, while calcitonin works to decrease blood calcium levels when high. Thyroid hormone regulates metabolism but is not involved in blood calcium homeostasis. Insulin and glucagon work to regulate blood glucose homeostasis. Adrenaline and noradrenaline both intensify the sympathetic nervous system response during the “fight-or-flight” response.

Both mechanical and chemical digestion occur in the stomach. Mechanical digestion includes churning, while chemical digestion includes the release of HCl and pepsin to degrade ingested proteins. The esophagus is not a site of digestion. The small intestine is a significant site of chemical digestion and nutrient absorption, but not mechanical digestion. The large intestine is a site of water reabsorption and storage of undigested food in preparation for elimination, but is not a site of mechanical or chemical digestion.

Day 1 of the menstrual cycle is the first day of menstrual bleeding. Ovulation usually occurs around day 14 in a normal 28 day cycle. This is when a surge of luteinizing hormone (LH) is released by the anterior pituitary gland, which stimulates ovulation and the conversion of the follicle into the corpus luteum.

Sperm are produced in the seminiferous tubules of each testis. Sperm are then stored in the epididymis to mature. The scrotal sac is located at the base of the penis and contains the testes, the epididymis, the external spermatic fascia, and the spermatic cord. The seminal vesicles secrete many components of semen. The Cowper’s glands produce pre-ejaculatory fluid upon arousal.

The kidneys regulate the body’s internal environment by filtering and processing blood. The kidney recycles minerals and resources still needed in the body while also excreting waste products. As a result, it is most like a wastewater treatment plant. The hypothalamus is the control center of the body, coordinating both endocrine and nervous system responses to information. One might consider the sites of B cell (bone marrow or lymph nodes) and T cell (thymus) maturation to be soldier training facilities in the body.

The eccrine sweat gland is the most widely distributed type of sweat gland. They are found in the skin throughout the body’s surface and are important in thermoregulation. Apocrine glands are sweat glands primarily located in the groin and armpits. Sweat glands are exocrine glands, not endocrine glands. Submucosal glands are those that secrete mucus, not sweat.

Superior means “above”, which correctly describes the first child’s position when reaching the top of the castle compared to the second child’s position who remains on the ground. Inferior means “below”, while anterior means “front” and posterior means “back.”

Extending an arm straight out to the side of the body would be described as a lateral movement, while returning it to the side of the body is a medial movement. Distal refers to being farther away from where the body part attaches to the trunk while proximal refers to being closer towards where the body part attaches to the trunk. Posterior refers to being toward the back of the body while anterior refers to being toward the front of the body. Inferior refers to being toward the lower part of the body while superior refers to being toward the upper part of the body.

A midsagittal plane divides the body into equal left and right sides and divides your face in half down the middle. A transverse (horizontal) plane divides the body into upper and lower sections. An oblique plane divides the body into sections at an angle, neither perfectly horizontally nor perfectly vertically. A frontal (coronal) plane divides the body into front and back sections.

The axial skeleton includes the bones of the skull (including the temporal bone), the vertebral column, the ribs, and the sternum. The appendicular skeleton includes the bones composing the shoulder (including the scapula) and hip girdles and the extremities, including the bones of the arm (where the ulna is found) and the leg (where the fibula is found).

The trachea, lungs, and bronchi are part of the lower respiratory system while the nose, pharynx, and larynx are part of the upper respiratory system.

The superior vena cava returns blood from the upper part of the systemic circuit to the heart. The coronary sinus is where blood from the myocardium returns to the right atrium of the heart. The aorta received freshly oxygenated blood from the heart to begin the systemic circuit. The pulmonary vein returns freshly oxygenated blood to the heart from the lungs in the pulmonary circuit.

These types of hormones are known as tropic hormones. Tropic hormones act on other endocrine glands. Organs with secondary endocrine function are those that have other primary functions but also have endocrine functions; such organs include the heart, kidneys, and intestines. None of the hormones listed are secreted by an organ with secondary endocrine function. None of the hormones listed are steroid hormones. And none of the hormones listed are secreted by the adrenal glands (the adrenal cortex and the adrenal medulla).

Mastication (chewing) in the mouth increases the food's surface area and promotes easier digestion by allowing enzymes more access to all of the food molecules. Mastication is a form of mechanical digestion. Mastication has nothing to do with protein absorption, and it aids in digestion (it does not prevent it). Bicarbonate from pancreatic juices helps to buffer acidic chyme entering the small intestine from the stomach; mastication has no effect on this.

The hypothalamus produces gonadotropin-releasing hormone (GnRH), which in turn prompts the anterior pituitary gland to release luteinizing hormone (LH). LH stimulates the interstitial cells of the testicles, also known as Leydig cells, to produce testosterone. Estrogen in males is important for regulating spermatogenesis, libido, and erectile function. Follicle-stimulating hormone in males regulates sperm production. Growth hormone stimulates growth in all organs and is not associated with the production of testosterone in males.

During inhalation, the diaphragm and external intercostal muscles between the ribs contract, increasing the size of the thorax. This decreases the air pressure in the lungs. Because air moves from an area of higher pressure to an area of lower pressure, air is drawn into the lungs. Upon exhalation, the diaphragm and external intercostal muscles relax, the thorax decreases in size, and the air pressure in the lungs increases, pushing air out of the lungs.

The patella is a sesamoid bone. Flat bones include the sternum, the ribs, the pelvic bones, and the bones of the skull. Long bones include various bones of the limbs including the femur and humerus. Irregular bones include the vertebrae and sacrum.

While most arteries in the body carry oxygenated blood away from the heart and most veins in the body return deoxygenated blood to the heart, the pulmonary arteries and veins are exceptions. Each pulmonary artery carries deoxygenated blood, just returned to the heart, to the lungs for gas exchange. And each pulmonary vein carries oxygenated blood from the lungs back to the heart.

The stratum basale (also known as the stratum germinativum) layer is the deepest layer of the epidermis and is the one that contains cells that undergo mitosis. Then, from deepest to most superficial, the layers are the stratum spinosum, the stratum granulosum, the stratum lucidum, and the stratum corneum.

There are two major body cavities: the dorsal cavity and the ventral cavity. The ventral cavity includes the thoracic and abdominopelvic cavities. The dorsal cavity includes the cranial and spinal cavities.

The process that reduces the number of chromosomes in a cell in half is called meiosis. This is important for gamete formation. When two gametes meet, fertilization. Both binary fission (prokaryotes) and mitosis (eukaryotes) result in the daughter cells having the same number of chromosomes as the parent cell.

Adipose tissue is located in the hypodermis (also known as the subcutaneous layer) of the skin. Both the stratum corneum and the stratum granulosum are found within the epidermis and neither have adipose tissue. The dermis also lacks adipose tissue.

The thoracic section of the vertebral column has 12 vertebrae, more than any other section. The cervical section has 7 vertebrae, and the lumbar and sacral sections each have 5 vertebrae (although the sacral vertebrae fuse to form the sacrum).

The pancreas secretes glucagon when blood glucose levels are low to increase blood glucose levels. The adrenal medulla (not the adrenal cortex) secretes adrenaline. The anterior pituitary (not the thyroid) secretes thyroid stimulating hormone. The thyroid (not the parathyroid) secretes calcitonin.

Platelets are cell fragments derived from thrombocytes. Collectively, erythrocytes, leukocytes, and erythrocytes compose the formed elements (cells and cell fragments) within blood. Erythrocytes are red blood cells while leukocytes are white blood cells. Lymphocytes are a type of leukocyte.

The chemical digestion of proteins occurs primarily in the stomach and the small intestine. The chemical digestion that occurs in the mouth is primarily that of carbohydrates by salivary amylase. Chemical digestion does not occur in the esophagus or the large intestine. In the stomach, the action of HCl secretion and pepsin chemically digests proteins. Pancreatic enzymes that are secreted into the small intestine, in addition to enzymes secreted by the small intestine itself, further chemically digest proteins in the small intestine.