sys health OPT Flashcards
What is the correct order in which inhaled air reaches our lungs?
a- Nasal cavity-> bronchi-> pharynx-> trachea-> larynx-> lungs
b- Nasal cavity-> larynx -> pharynx ->trachea-> bronchi-> lungs
c- Nasal cavity-> pharynx-> bronchi ->larynx-> trachea -> lungs
d- Nasal cavity-> pharynx-> larynx-> trachea-> bronchi-> lungs
e- Nasal cavity-> larynx-> trachea-> pharynx-> bronchi-> lungs
d- Nasal cavity-> pharynx-> larynx-> trachea-> bronchi-> lungs
Inhaled air enters through the nasal or the oral cavity and is then swept down the pharynx. The pharynx, also known as the throat, connects the mouth and the nose to the larynx. The pharynx is also attached to the esophagus. Air then passes through the larynx (also called the voice box). From the larynx, air flows through the trachea which divides into 2 bronchi leading to the right or left lung.
An accumulation of which of the following metabolic wastes is associated with gout?
Urea
Uric acid
Ammonia
Nitric acid
Carbon dioxide
Uric acid
Uric acid is a waste product created when nucleic acids are broken down. If uric acid is not eliminated in the urine, it may accumulate and crystallize in joints, causing gout. Initially, patients who experience gout will often complain of pain in their big toe, knee, or ankle; these are the most common joints to be affected.
Ammonia is formed during the process of deamination, wherein the amino groups are removed from amino acids that contain nitrogen.
Protein metabolism results in the formation of urea in the liver; this is caused by the joining of two ammonia molecules with carbon dioxide. Some urea that is filtered by the kidneys is reabsorbed; the rest of it is eliminated in the urine.
Kidney function is measured by evaluation of blood urea nitrogen. If these levels are found to be elevated, then the culprit is either depressed kidney function, body dehydration, heart failure, or a poor diet.
The body rids itself of the waste product carbon dioxide via exhalation through the lungs.
Cartilage is an important transition tissue during development. The cartilage matrix is composed of which type of cell?
Oligodendrocytes
Osteocytes
Fibroblasts
Chondroblasts
Chondroblasts
Chondroblasts are important for the production of the cartilage matrix. Once mature, chondroblasts become chondrocytes and reside in cavities within the cartilage matrix called lacunae.
Osteocytes are found in the bone matrix in small cavities, lacunae. Osteocytes are derivatives of osteoblasts and are important in bone remodeling. These cells serve an important role in releasing calcium from bones when the body’s calcium level becomes depleted.
Fibroblasts are found in abundance throughout the body and are important in the secretion of ground substance or extracellular matrix (generally proteins and polysaccharides) as well as the secretion of collagen fibers.
Oligodendrocytes are important for the production of the myelin sheath in the central nervous system.
Prostaglandin analogs are effective intraocular pressure-lowering medications that work PRIMARILY via which of the following mechanisms?
Increase aqueous outflow through the trabecular route
Correct answer Increase aqueous outflow through the uveoscleral route
Decrease aqueous production by ultrafiltration
Decrease aqueous production by active secretion
Explanation - There are several mechanisms of action that intraocular pressure (IOP) lowering medications utilize to decrease the pressure in the eye. These include medications that work to decrease the production of aqueous and those that lower pressures by increasing the rate of outflow of aqueous humor. The medications that increase aqueous outflow also have two ways in which they may act: by increasing aqueous outflow through the trabecular meshwork, or by increasing aqueous outflow through the uveoscleral pathway. Prostaglandin analogs specifically affect the uveoscleral route by triggering a cascade of events that leads to degradation of collagen and subsequent opening of intracellular spaces. This allows for greater drainage of aqueous fluid out of the anterior chamber, resulting in lower intraocular pressure.
Cholinergic agonists (such as pilocarpine) have a mechanism of action that works to also increase the outflow of aqueous; however, they specifically act on the trabecular meshwork pathway.
Topical medications that decrease aqueous production include beta-blockers and carbonic anhydrase inhibitors.
It is important to note that alpha-2 agonists have a dual mechanism of action. This class of medication decreases IOP by both increasing uveoscleral outflow and decreasing aqueous production.
The sella turcica is a deep depression in the superior surface of the sphenoid bone that houses which of the following glands?
Hypothalamus
Pituitary gland
Thyroid gland
Pineal gland
Pituitary gland
The sella turcica is a deep, saddle-shaped depression in the sphenoid bone of the skull that holds the pituitary gland. The floor (or seat of the saddle) is known as the hypophyseal fossa in which pituitary gland rests. Due to the configuration of the sella turcica, a tumor of the pituitary gland will typically extend upward into the suprasellar region, which can result in compression of the optic chiasm, causing a bitemporal hemianopic field defect.
A 43 year-old patient is referred to your office for further evaluation of her headaches. She reports that the headaches are moderate-to-severe, they occur almost daily, and are worse in the mornings when she wakes up and generally lessen or abate during the day. She reports that drinking black caffeinated coffee first thing in the morning usually makes her headaches go away. Based upon the case history alone, what is the MOST likely type of headache that she is experiencing?
Hypertension headache
Nasal sinusitis headache
Tension headache
Migraine headaches
Hypertension headache
Hypertension headaches typically occur secondary to poor control of blood pressure. This type of headache is typically described by patients as severe and is worse in the morning. Hypertension headaches are generally present upon awakening and abate at some point during the day. Many patients report that the headaches can be lessened or eliminated by drinking black caffeinated coffee.
Tension headaches, also known as muscular contraction headaches, are most commonly caused by stress and may be also be attributed to poor posture, hunger and fatigue. This type of headache is associated with stiffness of the muscles in the neck region and pain around the occipital region or a vice-like pain in the frontal area. Patients typically report the presence of a throbbing pain. Tension headaches are the most common type of headache.
Migraine headaches are thought to be neurological in nature and can be triggered by several mechanisms such as hormonal changes or neurotransmitter imbalances. A typical presentation of a patient suffering from a migraine headache will include unilateral pain that is pulsating in nature and lasts from 2-72 hours. Patients will typically experience associated symptoms of nausea, vomiting, photophobia, and phonophobia. Up to 30% of patients will perceive an aura immediately preceding the headache that typically involves transient visual disturbances, as well as sensory, language, or motor disruptions. Some migraine attacks can be suspended by the ingestion of strong coffee.
Sinus headaches are commonly associated with a deep and constant pain in the location of the cheekbones, forehead, or bridge of the nose. Pain in these cases is usually associated with other sinus symptoms such as rhinorrhea, feeling of fullness in the ears, fever, facial swelling, and lacrimation. Patients typically report a transient loss of the sense of smell. The majority of patients will note an increase in pain/pressure when bending down.
You see a patient with a subluxated lens; you suspect which of the following conditions?
Grave’s disease
Posner-Schlossman
Marfan’s syndrome
Coloboma
Marfan’s syndrome
Explanation - Marfan’s syndrome is a genetic condition demarcated by height, a high arch palate, and very long fingers. With Marfan’s syndrome there are collagen deficiencies, one of which has lead to the subluxation of the lens. Homocystinuria is another condition that may cause lens subluxation and is associated with very high levels of homocysteine and susceptibility to heart disease.
During respiration, what normally keeps the pleural membranes from rubbing against one another?
The diaphragm
The thoracic wall
Intrapleural fluid
The respiratory bronchioles
Intrapleural fluid
The pleural membranes are separated by an intrapleural space that is filled with intrapleural fluid; the fluid serves to prevent the two membranes from rubbing against one another. Some illnesses like pneumonia can cause inflammation of the pleurae, leading to chafing and painful ventilation called pleurisy.
Which of the following structures of the ear plays a role in hearing?
Utricle
Semicircular canals
Organ of Corti
Saccule
Organ of Corti
The inner ear contains the cochlea. The floor of the cochlear duct houses the basilar membrane, which serves as a bed for the organ of Corti. Hair cells of the organ of Corti protrude upwards onto a membrane called the tectorial membrane. Sound waves cause the fluid in the cochlea to move, which vibrates the basilar membrane. This vibration in turn pushes the hair cells against the tectorial membrane and causes the hair cells to bend. The bent hair cells release a neurotransmitter, resulting in action potentials of the auditory nerve.
The semicircular canals are a part of the vestibular apparatus along with the utricle and saccule. The semicircular canals are positioned at right angles to each other and help to code for acceleration, deceleration, and rotational head movements (angular acceleration). The semicircular canals are filled with fluid (endolymph). At the base of the canals are the ampullae that rest atop specialized hair cells that bend in response to the movement of fluid, allowing for processing by the brain.
The utricle and the saccule are sac-like, filled with fluid, and help to detect linear acceleration. These structures contain small calcium carbonate stones called otoliths. Each sac contains hair cells embedded in a jelly-like mass along with the otoliths. Movements of the mass and the otoliths signal a change in position of the head or body. Movement at constant speed will not be detected by these structures because the otoliths eventually come to equilibrium.
The brown color of human feces is attributable to which of the following components?
Bile pigments
Hydrochloric acid
Ingested food
Shed blood cells
Human feces typically displays a beautiful brown color due to the presence of bile pigments from the liver and gallbladder used in the digestion of fat. Although the food that we ingest can alter the color of fecal matter, it is generally colored brown. If blood is found in the stool it will change the color to black if the bleeding occurs in the stomach or small intestine or red if the bleeding results from rectal tears, hemorrhoids or other problems.
The nerve tract that serves to maintain communication between the cerebral hemispheres is named which of the following?
The corpus callosum
The thalamus
The red nucleus
The ventricles
The corpus callosum
The brain is divided into two hemispheres, both of which are capable of functioning independently. In terms of function, the left hemisphere is thought largely to govern spoken language skills while the right houses the centers for math, music and other nonverbal, abstract thinking. The two hemispheres are connected by a nerve tract called the corpus callosum which facilitates communication between the two sides.
The exact purpose of the red nucleus is still not fully understood but it is widely believed to be involved in motor function.
The thalamus serves as a relay for sensory information; it projects sensory signals to the appropriate destination.
The ventricles total four in number and function to synthesize and secrete cerebrospinal fluid (CSF).
Homocysteine levels can be reduced by which of the following vitamins?
B vitamins
Vitamins A and D
Vitamin C
Vitamin E
B vitamins
The B vitamins, B12, B6, and folic acid (also known as B9) can reduce homocysteine levels. The other vitamins have no impact on homocysteine. Homocysteine is a metabolic product of the metabolism of methionine. It is associated with premature atherosclerosis and thrombotic complications such as thrombophlebitis. There is great excitement in the medical community about the ability of B vitamins to reduce homocysteine levels; they have been found to do so in multiple studies. Unfortunately, a reduction in cardiovascular disease has not occurred as a consequence of the reduction in this risk factor. It is probably appropriate to maintain homocysteine within a healthy range by restricting foods that are high in methionine and by maintaining an adequate supply of these B Vitamins.
