Physiology Review Flashcards
Which pairing of an intravenously administered fluid and its effect on both intravascular fluid volume (IV) and extracellular fluid volume (ECV) would be correct in a normal patient?
Tonicity is given relative to normal plasma. Assume a simple 2-compartment model (vascular space [blood/plasma] and extracellular fluid space).
Isotonic (normal) saline; increase in IV; no change in ECV
A 55-year-old man with a longstanding history of alcoholism is found in a coma following ingestion of an unknown substance. Lab results show BUN of 11 mg/dL, serum sodium of 110 mEq/L, and blood glucose of 70 mg/dL, but serum osmolality of 450 mOsm/L. What finding is most expected?
Coma resulted from ingesting a high osmolarity substance
What substance readily diffuses across the cell membrane without facilitation?
Carbon dioxide
What differentiates osmosis from diffusion?
Osmosis seeks to equalize the concentration of solvent
What substance uses osmosis to cross the cell membrane?
Water
What is the primary function of active transporters in the cytosol of a cell?
Regulate cytosolic pH
How does an uncharged molecule move through a membrane during passive transport?
Concentration gradient
Active transport requires energy to move substances against a concentration or electrical gradient. What is the primary source of energy for primary active transport?
Adenosine triphosphate
Primary active transport involves an ATP-powered pump and what other molecules?
Sodium and potassium
What is an example of secondary active transport?
Sodium-calcium antiporter
Diffusion is a mechanism by which molecules are transported across the cell membrane. Several factors can affect the rate of diffusion. Which description accurately explains one of these factors?
Higher temperature increases the rate of diffusion
What is the most common extracellular cation in the human body?
Sodium
When a neuron begins the process of depolarization, what ion’s concentration begins to rapidly increase within the neuron cell membrane?
Sodium (Na++)
What substance is most often transported through the cell membrane via active transport?
Potassium
What electrical signal unique to muscle and nerve cells is created by a change in voltage across the cell membrane?
Action potential
How does a severely low serum potassium affect the cardiac action potential?
Repolarization time is prolonged
Which process triggers an action potential?
Depolarization of the membrane
Action potentials occur in excitable cells (neurons, muscle cells), allowing charged particles to pass through a channel into the cell membrane. What type of ion channel is primarily associated with somatosensation?
Mechanically-gated channel
What structure in the cell membrane contributes most to the hydrophilic outer aspect and hydrophobic inner aspect of the membrane?
Phospholipids
What type of integral protein in the cell membrane is used to pass ions from one side of the cell membrane to the other?
Channel protein
What component of the phospholipid layer is most responsible for the hydrophilicity of the molecule?
Phosphate
If the nervous system is suddenly stimulated by a perceived threat, what change causes an increase in arterial pressure?
Blood volume becomes increased in all chambers
A patient has a systolic blood pressure of 120 mm Hg and a diastolic blood pressure of 70 mm Hg. What is this patient’s pulse pressure?
50 mm Hg (pulse pressure is difference between systolic and diastolic; 120 mm Hg - 70 mm Hg = 50 mm Hg)
Arteriosclerosis, a leading cause of hypertension, affects which variable that influences blood pressure and blood flow?
Compliance
Which vessel is the first to branch off of the aorta, carrying oxygenated blood into systemic circulation?
Coronary artery
What component of the circulatory system carries oxygenated blood from the lungs into the heart?
Pulmonary vein
The vessels in the body are divided into two divisions according to the type of blood they carry. How do arteries differ from veins?
Arteries have thicker and more elastic walls
Unlike most arteries, the pulmonary arteries do not carry oxygenated blood from the heart to the tissues. What other artery shares this characteristic?
Umbilical arteries
What hormone secreted in response to low blood pressure maintains fluid balance in the body by opening aquaporin channels, increasing the water uptake by the kidneys?
Vasopressin
A patient with liver disease presents with ascites. What is the primary mechanism related to edema occurring with liver disease?
Decreased oncotic pressure
A patient presents with lower extremity edema and is found to have a serum albumin level of 2 g/dL (normal: >3.5d/dL) secondary to liver failure.
What force is responsible for the development of this patient’s edema?
Decreased intravascular oncotic pressure
What set of tissues composes human blood?
Plasma, platelets, red blood cells, and white blood cells
What is the main role of neutrophils in the blood?
Destroy bacteria through phagocytosis
What type of blood cell grows from a lymphoid precursor cell?
Natural killer cell
What type of leukocyte is activated in parasitic worm infections and is a marker for this type of infection?
Eosinophil
In an emergency situation, blood from a universal donor can be given. What blood type is reflected in a “universal donor” status?
O-negative
Why is type O negative blood considered a universal donor?
It has no antigens on the outside of the red blood cells
What type of blood type most contributes to the development of erythroblastosis fetalis in pregnancy?
Rh factor incompatibility
ABO/Rh classification of blood indicates the different antigens that are possibly present on the red blood cell (RBC) surface. In a scenario where emergency blood or plasma transfusion is necessary, which blood type would be a universal donor of RBCs and which blood type would be a universal donor of plasma, respectively?
O-, AB+
A 25-year-old healthy Rh-negative woman is pregnant with an estimated gestational age of 3 months (end of the first trimester). An amniocentesis reveals that her fetus is Rh-positive. Her past medical history is significant for a single prior pregnancy, which she remembers was Rh-negative, was carried to term, and was delivered at home. She remembers only that the baby was healthy and can recall no further details.
What is most appropriate in the care of this patient?
Continue routine prenatal care, Rh immune globulin after delivery
What molecule is a naturally occurring anticoagulant?
Antithrombin
Hemostasis is the physiological response that stops bleeding at the site of an injury. What is the function of insoluble fibrin?
Stabilize the blood clot
During trauma or injury, the body initiates the repair of the damaged tissue. What cells are responsible for developing a mesh-like clot to prevent further loss of blood?
Platelets
Factor XII is exposed to endothelial collagen and becomes Factor XIIA, an activated serine protease. A cascade of clotting factors follows and includes factors XI, IX, and X. Which factor displays the highest concentration throughout this progression?
X
What clotting factor specifically involves the common pathway?
Factor II
What clotting molecule is exclusively linked to the extrinsic pathway?
Thromboplastin
Which blood component is a granular leukocyte that produces and releases histamine as part of the immune respnose?
Basophil
Which agranular leukocyte in the blood is responsible for immunoglobulin production?
B lymphocyte
Leukocytes develop antibodies and protect against pathogens and other foreign bodies. What type of leukocyte is phagocytic?
Neutrophil
What molecule secreted by cytotoxic T cells aids in the immune destruction of infected cells?
Perforin
What cytokine is implicated in transplant rejection and can be measured in an individual suspected of having an autoimmune disorder?
Interleukin-6
What type of immune cell participates in B cell differentiation and secretes cytokines necessary for the activation of B cells?
Th2 cells
A scientist wants to develop a new drug to inhibit T-cell proliferation and antibody formation to aid in immunosuppression for patients receiving organ transplants. What molecular component should the drug target?
Interleukin-2
What disease-modifying anti-rheumatic drug (DMARD) is used to treat rheumatoid arthritis?
Methotrexate
What autoimmune disease is treated mainly with thyroid replacement therapy?
Hashimoto’s disease
What autoimmune disease is treated with NSAIDS and Plaquenil or another antimalarial drug?
Systemic lupus erythematosus
What biological agent is used to treat the autoimmune disease rheumatoid arthritis?
Etanercept
What is the movement sequence of the signal in the nerve cell?
Dendrites, cell body, axon, axon terminals
During a neuron action potential, what is the millivolt potential across the membrane when the nerve cell is completely depolarized?
+30 millivolts
At the motor end plate of the neuromuscular junction between the nerve and skeletal muscle, an action potential is created. What part of this process begins the formation of the action potential?
Sodium enters the cell
Some postsynaptic receptors cause excitation upon activation, where others cause inhibition. What is associated with excitation?
Decreased conduction through chloride channels
The corticobulbar tract sends ipsilateral signals from the motor cortex as descending pathways originating in the Betz cells. Where do these terminate?
Brainstem
Which motor spinal tract sends fibers from the cortex of the brain to control the muscles of the appendicular skeleton?
Lateral corticospinal tract
What motor tract sends signals to the spinal cord to control the muscles of the trunk?
Anterior corticospinal tract
Which phase in the creation of a muscle fiber twitch involves calcium ion flowing out of the sarcoplasmic reticulum without inducing a change in the muscle fiber?
Latent phase
What mechanism is regulated by parasympathetic response?
Digestion
Which component of the nervous system is idle during an emergency or a stressful period?
Parasympathetic
What part of the central nervous system gives rise to sympathetic responses?
Thoracic spinal cord
What portion of the autonomic nervous system involves very long pre-ganglionic fibers, very short post-ganglionic fibers, and primary usage of the neurotransmitter acetylcholine?
Parasympathetic nervous system
Which neurodegenerative disease is most linked to a buildup of alpha-synuclein protein in the brain?
Parkinson’s disease
Where in the brain does alpha-synuclein collect to cause the majority of symptoms of tremor and rigidity in Parkinson’s disease?
Substantia nigra
What neurodegenerative disease is most linked to a buildup of beta-amyloid protein in the brain affecting interneuron communication?
Alzheimer’s disease
What neurodegenerative disease involves the buildup of prion proteins leading to the rapid progression of neurodegeneration of the brain?
Creutzfeldt-Jakob disease
What type of molecule is involved in growth hormone?
Protein
What is the major difference between a hormone and an autocrine signaling molecule?
Hormones act on a distant cell type
What type of hormone is lipid-soluble and can act within the cell instead of using a hormone receptor on the cell’s surface?
Steroid
A peptidic chemical produced by the anterior pituitary gland is secreted in a pulsatile pattern through stimulation by growth hormone-releasing hormone.
What inhibits secretion of this chemical?
Somatostatin
A chemical affecting the liver and gall bladder is decreasing blood flow, inhibiting contraction of the gall bladder and inhibiting bile duct secretion.
What effect will this chemical have within the gastrointestinal system?
Inhibition of salivary amylase
What is the primary difference between an endocrine hormone and an exocrine hormone?
Endocrine hormones are released into the blood or lymph system
Which endocrine structure is acted upon most directly by the hypothalamic hormones?
Pituitary gland
Which hypothalamic hormone inhibits the release of growth hormone and is referred to as somatostatin?
GHIH
Which pituitary hormone acts on the salt and water balance in the body?
Vasopressin
What hormone is made by the anterior pituitary gland and acts on the gonads?
Luteinizing hormone
Which hormone is made by the anterior pituitary gland and is inhibited in its release by somatostatin?
Growth hormone
Which hypothalamic hormone is stored by the posterior pituitary and acts on the mammary glands to cause the let-down reflex?
Oxytocin
What nutrient deficiency is most likely to lead to hypothyroidism?
Iodine
What is most likely to be a symptom of congenital hypothyroidism in children born with the disease?
Cognitive deficits
What is the most common condition leading to the development of hyperthyroidism?
Graves’ disease
What symptom is most likely in a patient with hyperthyroidism?
Weight loss
What is the main activity of parathyroid hormone on bone cells?
Stimulates osteoclast activity
What hormone affects bone metabolism by directly stimulating osteoclast activity?
Parathyroid hormone
What is the immediate source of calcium when parathyroid hormone is released in response to hypocalcemia?
Bone
A single-chain polypeptide hormone stimulates conversion of vitamin D into its active metabolite.
Under normal conditions, what triggers secretion of this chemical?
Decrease in serum calcium
Parathyroid hormone is stimulating calcium release from bone storage. What type of cell contains the receptor for this chemical?
Osteoblast
What hormone has activity that directly opposes the action of parathyroid hormone on bony tissue?
Calcitonin
What is the major stimulant for the release of parathyroid hormone in the healthy human body?
Hypocalcemia
What hormone is secreted when the blood glucose level is low?
Glucagon
Which hormone of the endocrine pancreas is most responsible for lowering blood glucose levels?
Insulin
What cell in the endocrine pancreas is responsible for making glucagon, raising blood sugar levels?
Alpha cell
A chemical is synthesized by delta cells in the pancreas, is secreted, and travels to its receptor.
What effect will occur in the gastrointestinal system?
Delayed gastric emptying
A glucose transporter within the cytoplasm of a cell receives an insulin signal and translocates to the cellular membrane for uptake.
What tissue requires this process for glucose entry?
Muscle
What is the primary effect of the hormone insulin?
Glucose uptake
How does cortisol prevent the development of inflammation?
Stabilizing the lysosomal membranes
Adrenocortical hormones are produced by the outer region of the adrenal gland (adrenal cortex) and primarily function in response to stress. The adrenal cortex has three distinct layers. What hormone is secreted by the cells of the outer layer?
Aldosterone
What hormones are specifically released by the zona glomerulosa of the adrenal cortex?
Mineralocorticoids
A drop in blood glucose triggers release of a glucocorticoid from the zona fasciculata. What effect will be mediated by release of this chemical?
Simulation of gluconeogenesis
What is the primary effect of mineralocorticoids released by the adrenal cortex?
Increase blood sodium levels
What endocrine disease results from overproduction of sympathomimetic hormones?
Pheochromocytoma
What endocrine disorder stems from hypersecretion of the hormones of the adrenal cortex?
Cushing disease
What endocrine disease leads to chronic dehydration from underproduction of antidiuretic hormone?
Diabetes insipidus
A patient presents with hyperglycemia, polyuria, blurred vision, and headache. They are diagnosed with a condition associated with impaired insulin secretion.
What cells are characteristically destroyed as a result of this condition?
Beta cells
What disease is caused by an insufficiency of hormones from the adrenal gland?
Addison’s disease
The motor neuron and muscle fiber connect at the neuromuscular junction. What space is crossed by the neurotransmitter to send the message from the neuron to the muscle fiber?
Synaptic cleft
A patient sustains a myocardial infarction (heart attack) that damages the ventricular septum of the heart. What effect on the heart is most likely to be seen immediately after the heart attack?
Changes in the electrical conduction of the heart
At what point of fetal development does sexual differentiation begin?
9-12 weeks
Some postsynaptic receptors cause excitation upon activation, where others cause inhibition. What is associated with excitation?
Decreased conduction through chloride channels
The renal system is able to regulate the rate of renal blood flow and glomerular filtration rate (GFR) over a wide range of blood pressures. Which description applies to an intrinsic mechanism for autoregulation of blood flow?
Reduces excess filtrate formation to maintain normal GFR
Arteriosclerosis is a leading cause of hypertension. Which variable that influences blood pressure and blood flow does arteriosclerosis affect?
Compliance
What cells of the nephron in the kidneys will secrete hydrogen ions or bicarbonate to regulate acid-base balance in the body?
Intercalated cells
How is eukaryotic translation different from prokaryotic translation?
Eukaryotic translation is not coupled with transcription
How do general transcription factors work?
Binding DNA to position RNA polymerase at its promoter
A 10-year-old boy is admitted to the hospital with chest pain. An ECG is done revealing a normal sinus rhythm. This is an indication that electrical excitation originates from what location?
Sinoatrial node
What hormone affects bone metabolism by directly stimulating osteoclast activity?
Parathyroid hormone
Lipodystrophy is a condition characterized by atrophy or genetic deficiency of the adipocytes. What would a patient with lipodystrophy present with?
Excessive fat storage
What enzyme is secreted by the kidneys to increase blood pressure in response to low blood flow through the kidneys?
Renin
Cardiac output is the volume of blood the heart pumps in one minute. If a person’s heart rate is 80 beats per minute, moving 75 mL from the left ventricle with each contraction, what is their cardiac output?
6 L/minute (cardiac output equals the stroke volume times the heart rate; CO = SV x HR)
Atropine is a drug designed to paralyze the cholinergic nerve endings of the myenteric plexus. What impact is atropine likely to have on peristalsis?
Nearly blocking peristalsis because myenteric plexus activation is required
A woman has recurrent viral infections. Her physician orders a series of tests and discovers that the level of the cells most responsible for fighting virus-infected cells is depleted. What cells are depleted in this patient?
Cytotoxic T lymphocytes
What substance uses osmosis to cross the cell membrane?
Water
What substance crosses the cell membrane through simple diffusion?
Carbon dioxide
What symptom is most likely in a patient with hyperthyroidism?
Weight loss
The process of chemical digestion breaks down large food molecules into smaller units that can be absorbed in the alimentary canal. The digestion of protein begins in which part of the gastrointestinal tract?
Stomach
During mitosis and meiosis, where are spindle microtubules attached to the chromosome?
Kinetochore
What electrical signal unique to muscle and nerve cells is created by a change in voltage across the cell membrane?
Action potential
Respiration refers to the use of oxygen and removal of carbon dioxide by the body as a whole, or by individual cells. What is the primary determinant of ventilatory rate (respiratory minute volume)?
Blood levels of CO2
A patient is diagnosed with peripheral arterial disease (PAD), which is the buildup of inflammatory plaques within the arteries that can restrict blood flow to tissues or flow back to the heart. A class symptom is pain in the legs with activity referred to as claudication. This patient reports that his pain gradually resolves with rest and that his symptoms are not otherwise bothersome. What recommendation would this patient most likely receive from their healthcare provider?
Increased exercise
In the microcirculation, the direction of passive exchange of water between the plasma and interstitial fluid is determined by the hydrostatic and oncotic pressures existing between the two compartments. What is true about the arterial side of capillary exchange?
Capillary hydrostatic pressure is at the highest level
What is the function of luteinizing hormone?
Ensures normal function of ovaries and testes
What is normally produced by alveolar cells?
Surfactant
A patient presents with lower extremity edema and is found to have a serum albumin level of 2 g / dL secondary to liver failure. What force is responsible for the development of this patient’s edema?
Decreased intravascular oncotic pressure
What portion of the autonomic nervous system involves very long pre-ganglionic fibers, very short post-ganglionic fibers, and primary usage of the neurotransmitter acetylcholine?
Parasympathetic nervous system
What molecule is a naturally occurring anticoagulant?
Antithrombin
What substance is most often transported through the cell membrane via active transport?
Potassium
The cardiac cycle is a process that begins with atrial contraction and ends with ventricular relaxation. Initially, both the atria and ventricles are relaxes. As the tricuspid and mitral valves are both open, 70-80% of ventricular filling occurs. What mechanism contributes the remaining 20-30%?
Atrial systole
Considering the direction of visual pathways in the brain, what part of the eyes does the left occipital lobe receive images from?
Right visual field of both eyes
How does the renal system contribute to the control of blood pH in response to acidosis?
Tubular cells reabsorb more bicarbonate
How does cortisol prevent the development of inflammation?
Stabilizing the lysosomal membranes
A 65-year-old woman reports that she is experiencing difficulty hearing, having to ask people to repeat what they have said. What is the primary factor associated with age-related hearing loss?
Gradual loss of sensory hair cells in the cochlea
At what level of the brain or spinal cord do ascending sensory pathways decussate (cross over) to make the sensory fibers from the spinal cord provide signaling to the contralateral cortex?
Medulla
The initial stages of spermatogenesis take place in the testes. Developing gametes mature and are stored in which internal structure of the reproductive system?
Epididymis
Through the “symport” process in the kidneys, several molecules and ions are co-transported in the proximal convoluted tubules of the kidneys along with sodium. What molecule is reabsorbed with sodium in this process?
Bicarbonate ions
You are caring for a patient who sustained a brain injury secondary to a motor vehicle collision. The patient is assessed to be very emotional and demonstrates impaired decision-making. The patient most likely sustained damage to which part of the brain?
Frontal lobe
The immune system consists of two major classes: innate immunity and adaptive immunity. What is the role of mast cells in innate immunity?
Release cytokines and chemical molecules initiating inflammatory cascade
Right heart catheterization can determine the mean pulmonary blood pressure. What is the range of this blood pressure in a healthy person?
11-20 mm Hg
Central and peripheral respiratory chemoreceptors serve to regulate breathing. In which of the following situations would one expect the chemoreceptors to decrease the respiratory rate?
A patient experiencing an anxiety attack
Pulmonary ventilation is the process of air flowing into and out of the lungs because of pressure differences between atmospheric pressure and the gases inside the lungs. What is true about the mechanics of inspiration?
Is the active phase of ventilation
What neuron is directly inhibited to allow deep tendon reflex to occur as a result of tapping the knee?
Flexor motor neuron
What female hormone is directly responsible for the classic “let-down reflex” that occurs during breastfeeding?
Oxytocin
With each heartbeat, the heart generates a sequence of electrical impulses. The electrical impulse from the sino-atrial (SA) node is recorded as the P wave on an electrocardiogram tracing. What is the effect on cardiac activity?
Contracting of the two upper chambers of the heart
Most hypothalamus hormones that have amine or peptide structures have rapid action in the body from the time they are secreted. In contrast, why can the full action of a steroid hormone take hours or even days to achieve?
Action at the nuclear hormone-receptor complex slows the process
If a patient ingests a poison that inhibits protein synthesis, what cellular organelle(s) is/are being targeted?
Ribosomes
