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WorksheetsProf En 1 - Physiology
Total questions: 150
Worksheet time: 2hrs 10mins
A 35-year-old patient exhibits muscle weakness with no signs of sensory loss. Nerve conduction velocity is normal. Which of the following is the MOST likely physiological explanation?
Demyelination of peripheral nerves
Inhibition of acetylcholinesterase
Decreased calcium release from the sarcoplasmic reticulum
Damage to the dorsal root ganglia
During high-intensity resistance training, which muscle fiber type undergoes the MOST hypertrophy?
Type I
Type IIa
Type IIb
Type III
Which of the following BEST explains why rigor mortis occurs after death?
Excess calcium is pumped into the SR post-mortem
Lack of ATP prevents detachment of myosin from actin
Increased ATP causes sustained contraction
Inhibition of acetylcholine release at the neuromuscular junction
In a case of muscular dystrophy, what is the PRIMARY pathophysiological mechanism that leads to progressive muscle weakness?
Loss of troponin binding
Overactivation of myosin ATPase
Defective dystrophin protein affects sarcolemma integrity
Excessive accumulation of acetylcholine in the synapse
Which molecular event occurs IMMEDIATELY AFTER the action potential reaches the T-tubule?
Cross-bridge detachment
Opening of ryanodine receptors on the SR
Binding of calcium to troponin C
Release of acetylcholine from the axon terminal
A 45-year-old athlete complains of fatigue during endurance activities. Which enzyme deficiency would MOST likely impair aerobic ATP production in skeletal muscle?
Creatine kinase
Myosin ATPase
Citrate synthase
Lactate dehydrogenase
Which of the following scenarios BEST demonstrates the concept of the length-tension relationship in skeletal muscle?
A muscle contracts more forcefully when overstretched
Maximum force is generated when actin and myosin overlap optimally
Muscle force is independent of initial muscle length
Greater passive tension always leads to greater active tension
A researcher inhibits ATP synthase in a skeletal muscle cell. What is the MOST immediate physiological consequence during contraction?
Increased cross-bridge cycling
Inability to release calcium from the SR
Reduced detachment of myosin from actin
Increased mitochondrial calcium uptake
In isometric contraction, which of the following BEST describes the muscle's behavior?
Muscle length increases while tension remains constant
Muscle length remains constant while tension increases
Muscle shortens without generating force
Muscle produces movement without neural input
A drug that blocks voltage-gated calcium channels at the axon terminal would MOST likely cause which of the following effects on skeletal muscle contraction?
Enhanced acetylcholine release and stronger contractions
No effect on muscle function
Decreased acetylcholine release and weakened contractions
Prolonged depolarization of the muscle fiber
A patient with severe burns presents with fluid loss and electrolyte imbalance. Which function of the skin is MOST directly compromised?
Immune defense
Sensory perception
Thermoregulation
Barrier protection
Which skin layer is primarily responsible for the generation of new keratinocytes?
Stratum corneum
Stratum granulosum
Stratum basale
Stratum lucidum
During wound healing, which phase is characterized by angiogenesis, fibroblast proliferation, and granulation tissue formation?
Inflammatory phase
Proliferative phase
Remodeling phase
Hemostatic phase
A patient is experiencing difficulty with thermoregulation in a hot environment due to impaired sweat gland activity. Which gland is MOST likely dysfunctional?
Sebaceous gland
Apocrine sweat gland
Eccrine sweat gland
Ceruminous gland
Vitamin D synthesis in the skin is primarily initiated in response to which of the following stimuli?
Heat exposure
UVA radiation
UVB radiation
Friction and pressure
Which of the following cells in the epidermis is MOST directly involved in immune surveillance and antigen presentation?
Merkel cells
Keratinocytes
Langerhans cells
Melanocytes
A 65-year-old patient with a history of diabetes presents with a non-healing ulcer. Which physiological impairment MOST likely contributes to delayed wound healing?
Increased fibroblast activity
Enhanced vasodilation
Impaired collagen synthesis
Overproduction of melanin
Which of the following BEST describes the role of melanocytes in the skin?
Synthesize keratin in response to UV exposure
Produce sebum for waterproofing the skin
Generate melanin for UV protection
Regulate epidermal turnover
What is the MAIN role of the arrector pili muscle in thermoregulation?
Enhancing blood flow to skin surface
Increasing sweat secretion
Causing hair to stand and trap heat
Stimulating melanocyte activity
Which of the following skin receptors is MOST sensitive to light touch and is located in the dermal papillae?
Pacinian corpuscle
Ruffini ending
Merkel disc
Meissner corpuscle
A 28-year-old female patient has been non-weight-bearing for 6 weeks due to a tibial fracture. What cellular activity is MOST responsible for the resulting bone density loss?
Increased osteoblast activity
Decreased osteoclast activity
Increased osteoclast activity
Increased chondrocyte proliferation
Parathyroid hormone (PTH) regulates serum calcium by acting on which of the following mechanisms in bone?
Stimulating osteoblasts to form new bone
Inhibiting osteoclast function
Activating osteoblasts to release RANKL
Enhancing collagen cross-linking
Which of the following BEST explains why older adults have a higher risk of fractures despite normal serum calcium levels?
Decreased osteoclast activity
Increased bone mineralization
Impaired osteoblast function and bone remodeling
Overproduction of growth hormone
During endochondral ossification, which of the following events occurs FIRST?
Formation of secondary ossification centers
Calcification of the cartilage matrix
Vascular invasion of the epiphyseal plate
Replacement of cartilage with trabecular bone
Which hormone plays the MOST DIRECT role in increasing intestinal calcium absorption and is produced in the skin, liver, and kidneys in sequence?
Calcitonin
Parathyroid hormone
1,25-dihydroxyvitamin D (calcitriol)
Cortisol
In a child with rickets, what is the PRIMARY physiological abnormality contributing to bone deformities?
Excessive bone resorption
Impaired cartilage formation
Inadequate mineralization of osteoid
Hyperactivity of osteoblasts
A patient has elevated serum alkaline phosphatase levels. Which of the following processes is MOST likely occurring in the skeletal system?
Decreased collagen synthesis
Increased osteoclast-mediated resorption
Active bone formation by osteoblasts
Decreased calcium absorption
Which of the following types of bone cells serves as the long-term calcium reservoir and can become active during periods of calcium demand?
Osteoblasts
Osteoclasts
Osteocytes
Chondrocytes
Mechanical loading and physical activity contribute to bone remodeling primarily through which of the following cellular mechanisms?
Chondrocyte proliferation
Osteocyte mechanotransduction
Osteoclast apoptosis
Inhibition of calcitonin release
Which of the following structural proteins is MOST abundant in the organic matrix of bone and provides tensile strength?
Elastin
Keratin
Type I collagen
Osteocalcin
A patient with multiple sclerosis shows slowed nerve conduction velocity. Which of the following is the PRIMARY physiological cause?
Decreased neurotransmitter release
Inhibition of sodium-potassium pumps
Demyelination of axons
Increased synaptic vesicle degradation
Which ion movement is MOST responsible for the rising phase of the neuronal action potential?
Influx of Na⁺ through voltage-gated channels
Efflux of K⁺ through leak channels
Influx of Cl⁻
Efflux of Ca²⁺
A physical therapist notices that a stroke patient cannot perceive vibration or proprioception on the right lower limb. Which pathway is MOST likely affected?
Spinothalamic tract
Corticospinal tract
Dorsal column-medial lemniscal pathway
Reticulospinal tract
Which of the following glial cells is MOST responsible for maintaining the blood-brain barrier?
Microglia
Astrocytes
Oligodendrocytes
Schwann cells
Inhibitory postsynaptic potentials (IPSPs) are typically caused by which ion movements?
Na⁺ influx or Ca²⁺ influx
K⁺ efflux or Cl⁻ influx
Na⁺ efflux or K⁺ influx
Ca²⁺ efflux or Cl⁻ efflux
Which of the following best explains the concept of temporal summation in a neuron?
Multiple synapses activated simultaneously
Single synapse repeatedly stimulated over time
One presynaptic terminal inhibits multiple neurons
Continuous release of acetylcholine without a stimulus
In the neuromuscular junction, what role does calcium play in neurotransmission?
Blocks Na⁺ channels on the postsynaptic membrane
Facilitates breakdown of acetylcholine
Triggers fusion of synaptic vesicles with the presynaptic membrane
Activates postsynaptic receptors directly
Which brain region is MOST associated with motor planning and the initiation of voluntary movement?
Primary somatosensory cortex
Basal ganglia
Cerebellum
Hippocampus
A patient exhibits flaccid paralysis and diminished reflexes after a spinal cord injury. Which type of motor neuron is MOST likely affected?
Upper motor neuron
Lower motor neuron
Interneuron
Sensory neuron
The cerebellum contributes to motor control by:
Initiating voluntary movement
Modulating reflex arcs
Coordinating timing, precision, and motor learning
Controlling autonomic functions
A patient with untreated hyperthyroidism presents with muscle weakness and heat intolerance. Which of the following best explains the muscle symptoms?
Increased protein synthesis and muscle hypertrophy
Excess cortisol release causing muscle catabolism
Increased basal metabolic rate leading to protein breakdown
Decreased sympathetic nervous system activation
Which hormone has a direct anabolic effect on skeletal muscle and is critical in post-exercise muscle repair?
Cortisol
Insulin
Epinephrine
Thyroxine
Which hormone is MOST responsible for preventing hypoglycemia during prolonged exercise?
Insulin secretion from pancreatic β-cells
Glucagon secretion from pancreatic α-cells
Decreased cortisol release
Decreased growth hormone levels
A postmenopausal woman is diagnosed with osteoporosis. Which hormonal change is MOST responsible for her decreased bone density?
Decreased estrogen
Increased aldosterone
Decreased insulin
Increased melatonin
Which of the following hormones uses intracellular (nuclear) receptors to alter gene transcription?
Epinephrine
Glucagon
Insulin
Cortisol
In a patient with Addison's disease (adrenal insufficiency), which of the following lab findings would MOST likely be present?
Hypernatremia and hypertension
Hyperkalemia and hyponatremia
Hypokalemia and hyperglycemia
Elevated cortisol and low ACTH
Which hormone increases calcium levels by stimulating osteoclast activity and increasing renal reabsorption of calcium?
Calcitonin
Parathyroid hormone
Aldosterone
Growth hormone
A patient presents with acromegaly. Which of the following would be the MOST direct cause of their condition?
Excessive secretion of TSH
Hyposecretion of insulin
Pituitary adenoma secreting growth hormone
Overproduction of cortisol
Which of the following accurately describes a negative feedback loop in endocrine physiology?
ACTH stimulates cortisol release, which enhances further ACTH production
Insulin release lowers blood glucose, which suppresses further insulin release
Estrogen stimulates GnRH release, increasing LH and FSH secretion
Parathyroid hormone increases bone resorption, which inhibits PTH synthesis via positive feedback
During acute stress (fight-or-flight response), which of the following is the PRIMARY immediate endocrine response?
Cortisol release from adrenal cortex
Glucagon release from pancreas
Epinephrine release from adrenal medulla
Growth hormone release from anterior pituitary
During quiet inspiration, which of the following muscles is the PRIMARY contributor to increasing thoracic volume?
External intercostals
Diaphragm
Sternocleidomastoid
Internal intercostals
A patient with restrictive lung disease has a decreased total lung capacity (TLC). Which of the following BEST explains the pathophysiological change?
Increased airway resistance
Decreased lung compliance
Increased surfactant production
Increased alveolar dead space
In which part of the lung is ventilation-perfusion (V/Q) ratio typically HIGHEST in an upright individual?
Apex of the lungs
Base of the lungs
Middle lobes
Diaphragmatic surface
Which of the following would MOST likely shift the oxygen-hemoglobin dissociation curve to the right, enhancing oxygen unloading to tissues?
Decreased temperature
Increased pH
Decreased 2,3-BPG
Increased CO₂ levels
A patient performing aerobic exercise shows increased respiratory rate and depth. What is the PRIMARY stimulus for this ventilatory response?
Low arterial oxygen
Elevated cerebrospinal fluid pH
High arterial CO₂
Increased airway resistance
In a healthy adult, which of the following lung volumes can NEVER be measured directly with spirometry?
Tidal volume
Inspiratory capacity
Vital capacity
Residual volume
A 72-year-old patient with emphysema exhibits increased functional residual capacity (FRC). What is the PRIMARY physiological mechanism?
Decreased surface tension
Air trapping due to loss of elastic recoil
Increased diaphragmatic strength
Enhanced airway clearance
Which of the following BEST describes the role of surfactant in alveolar function?
Increases alveolar surface tension
Facilitates gas exchange by increasing diffusion rate
Prevents alveolar collapse by reducing surface tension
Stimulates alveolar macrophages to clear pathogens
In obstructive lung disease, which spirometric change is MOST characteristic?
Increased FEV₁/FVC ratio
Decreased FEV₁
Increased inspiratory reserve volume
Decreased total lung capacity
Which of the following describes the PRIMARY mode of carbon dioxide transport in blood?
Dissolved in plasma
Bound to hemoglobin as carbaminohemoglobin
As carbonic acid
As bicarbonate ion (HCO₃⁻)
A patient has a resting oxygen consumption of 3.5 mL O₂/kg/min. This value corresponds to:
1 MET
2 METs
3 METs
5 METs
Which of the following cardiovascular changes occurs during moderate-intensity aerobic exercise (4-6 METs)?
Decrease in systolic BP
Decrease in stroke volume
Increase in heart rate and cardiac output
Decrease in mean arterial pressure
A patient performing an activity at 6 METs is consuming how much oxygen?
6 mL O₂/kg/min
21 mL O₂/kg/min
3.5 mL O₂/kg/min
35 mL O₂/kg/min
Which of the following is the PRIMARY determinant of cardiac output during exercise?
Peripheral vascular resistance
Stroke volume × heart rate
Mean arterial pressure
End-diastolic volume × afterload
During prolonged aerobic training, what cardiovascular adaptation is MOST likely to occur?
Increased resting heart rate
Decreased stroke volume
Increased capillary density and stroke volume
Decreased cardiac output at maximal exertion
A 70-year-old patient recovering from MI is cleared for submaximal exercise at 3 METs. Which of the following activities BEST represents this level?
Slow walking (2 km/h)
Sweeping floors or light gardening
Jogging at 8 km/h
Climbing stairs quickly
Which autonomic change supports increased cardiac output during early stages of aerobic exercise?
Decreased sympathetic tone and increased vagal output
Increased parasympathetic activity to the SA node
Increased sympathetic stimulation and reduced vagal tone
Vasoconstriction of skeletal muscle arterioles
During heavy exercise, how is blood flow redistributed to prioritize muscle perfusion?
By increasing coronary and renal blood flow
Through vasoconstriction of arterioles in active muscles
By shunting blood away from skin and toward viscera
Via vasodilation in active skeletal muscle and vasoconstriction in splanchnic beds
A patient with a low functional capacity can only perform activities up to 3 METs. What does this suggest about their aerobic fitness level?
Normal functional capacity
Moderate cardiorespiratory fitness
Severely reduced aerobic capacity
Above-average endurance
In terms of cardiac cycle dynamics, what happens to diastolic time as heart rate increases during exercise?
It increases proportionally
It remains constant
It decreases, reducing coronary perfusion time
It has no effect on myocardial oxygen demand
A patient is dehydrated following intense aerobic exercise. Which renal mechanism is MOST responsible for conserving water?
Decreased aldosterone secretion
Increased glomerular filtration rate (GFR)
Increased antidiuretic hormone (ADH) activity
Reduced sympathetic activity
Which nephron segment is the PRIMARY site for glucose reabsorption?
Distal convoluted tubule
Loop of Henle
Proximal convoluted tubule
Collecting duct
A Physical Therapy patient with chronic hypertension is taking an ACE inhibitor. Which renal hormone pathway is MOST directly affected?
ADH-Vasopressin system
Renin-Angiotensin-Aldosterone System (RAAS)
Erythropoietin synthesis
Natriuretic peptide pathway
Which of the following would be expected to INCREASE glomerular filtration rate (GFR)?
Constriction of the afferent arteriole
Dilation of the efferent arteriole
Increased plasma oncotic pressure
Dilation of the afferent arteriole
A patient in metabolic acidosis has increased renal excretion of hydrogen ions. Which nephron cell type is primarily responsible for this compensation?
Principal cells in the collecting duct
Podocytes in the glomerulus
Intercalated cells in the collecting duct
Macula densa cells in the distal tubule
Which of the following BEST explains the role of the macula densa in tubuloglomerular feedback?
Detects blood pressure in the afferent arteriole
Responds to low sodium levels in the filtrate to increase renin release
Releases aldosterone to regulate potassium excretion
Triggers vasoconstriction of the renal vein during stress
Which of the following substances is filtered but neither reabsorbed nor secreted, making it ideal for measuring GFR?
Glucose
Creatinine
Inulin
Urea
In prolonged endurance exercise, a drop in plasma volume occurs. Which hormone is released to restore sodium and water balance?
Epinephrine
Aldosterone
Glucagon
Insulin
Which of the following BEST describes the kidney's contribution to long-term blood pressure control?
Direct vasodilation of systemic arteries
Regulation of cardiac output
Adjustment of plasma osmolarity via urea
Regulation of extracellular fluid volume through sodium balance
Which renal adaptation is MOST important in maintaining acid-base balance during intense anaerobic exercise?
Decreased bicarbonate reabsorption
Increased ammonia production and H⁺ excretion
Increased sodium secretion
Reduced aldosterone activity
Which hormone secreted by the stomach stimulates gastric acid secretion and motility?
Secretin
Gastrin
Cholecystokinin (CCK)
Motilin
A patient has decreased motility of the colon. Which hormone or neurotransmitter dysfunction could contribute MOST to this symptom?
Excess serotonin
Decreased motilin
Excess somatostatin
Increased acetylcholine
Which layer of the GI tract is primarily responsible for peristalsis?
Mucosa
Submucosa
Circular and longitudinal layers of muscularis externa
Serosa
The hormone cholecystokinin (CCK) plays an important role in:
Stimulating pancreatic enzyme secretion and gallbladder contraction
Increasing gastric acid secretion
Promoting insulin release from the pancreas
Stimulating intestinal sodium absorption
Which hormone is primarily responsible for the development of male secondary sexual characteristics?
Follicle-stimulating hormone (FSH)
Luteinizing hormone (LH)
Testosterone
Estrogen
In the female menstrual cycle, the surge of which hormone triggers ovulation?
Estrogen
Progesterone
Luteinizing hormone (LH)
Follicle-stimulating hormone (FSH)
Which structure in the testes is responsible for sperm production?
Epididymis
Seminiferous tubules
Leydig cells
Vas deferens
During pregnancy, which hormone maintains the uterine lining and prevents menstruation?
Human chorionic gonadotropin (hCG)
Progesterone
Estrogen
Oxytocin
Which hormone primarily stimulates the Sertoli cells to support spermatogenesis?
Testosterone
Luteinizing hormone (LH)
Follicle-stimulating hormone (FSH)
Prolactin
The primary source of estrogen production during the follicular phase of the menstrual cycle is the:
Corpus luteum
Theca cells
Granulosa cells
Hypothalamus
Which hormone causes milk ejection (let-down) during lactation?
Prolactin
Oxytocin
Estrogen
Human placental lactogen
Which part of the brain regulates the release of GnRH (gonadotropin-releasing hormone)?
Medulla oblongata
Hypothalamus
Pituitary gland
Thalamus
In males, Leydig cells primarily produce:
Estrogen
Testosterone
Inhibin
Progesterone
The endometrial changes during the luteal phase are primarily due to increased levels of:
Estrogen
Progesterone
LH
FSH
Which immune cells are primarily responsible for presenting antigens to T lymphocytes?
B cells
Macrophages and dendritic cells
Neutrophils
Natural killer (NK) cells
The major histocompatibility complex (MHC) class I molecules present antigens to which type of immune cells?
CD4+ helper T cells
B cells
CD8+ cytotoxic T cells
Neutrophils
Which of the following is a PRIMARY function of neutrophils during acute inflammation?
Antibody production
Phagocytosis of pathogens
Cytokine secretion to activate B cells
Antigen presentation to T cells
Which cytokine is most involved in promoting fever during systemic infection?
Interleukin-10 (IL-10)
Tumor necrosis factor-alpha (TNF-α)
Interleukin-1 (IL-1)
Interferon-gamma (IFN-γ)
The antibody class primarily involved in mucosal immunity (e.g., respiratory and gastrointestinal tracts) is:
IgG
IgA
IgM
IgE
In the adaptive immune response, memory B cells function to:
Immediately destroy pathogens on first exposure
Produce large amounts of cytokines to recruit neutrophils
Provide a faster and stronger antibody response upon subsequent exposure
Present antigen to cytotoxic T cells
Natural killer (NK) cells kill target cells primarily by:
Producing antibodies
Phagocytosis
Releasing perforin and granzymes to induce apoptosis
Presenting antigen to helper T cells
Which of the following best describes the complement system's role?
Directly producing antibodies
Enhancing phagocytosis and lysing pathogens
Presenting antigen to T cells
Inhibiting neutrophil recruitment
Which cell type secretes histamine and plays a key role in allergic reactions?
Mast cells
Dendritic cells
T regulatory cells
Macrophages
Which immune mechanism is primarily responsible for tissue rejection in organ transplantation?
Autoantibody production
Activation of cytotoxic T cells against foreign MHC molecules
Complement activation only
Neutrophil infiltration
Which fibers are primarily responsible for transmitting fast, sharp, well-localized pain?
C fibers
A-delta fibers
A-beta fibers
Gamma fibers
The gate control theory of pain proposes that:
Pain signals are generated only by damaged tissue
Non-painful input can inhibit pain transmission at the spinal cord level
Pain perception occurs solely in the cerebral cortex
All pain signals bypass the dorsal horn
Which neurotransmitter is primarily involved in the transmission of pain signals in the spinal cord?
Dopamine
Glutamate
Acetylcholine
Serotonin
The descending pain modulatory system primarily uses which neurotransmitter to inhibit pain?
Norepinephrine
Substance P
Gamma-aminobutyric acid (GABA)
Endorphins and serotonin
Central sensitization in chronic pain results from:
Reduced responsiveness of spinal neurons
Increased excitability of dorsal horn neurons leading to amplified pain perception
Complete loss of peripheral nociceptors
Increased inhibitory neurotransmitter release
Which area of the brain is MOST involved in the emotional and motivational aspects of pain?
Primary somatosensory cortex
Amygdala and anterior cingulate cortex
Thalamus
Brainstem
The phenomenon where a normally non-painful stimulus causes pain is called:
Hyperalgesia
Allodynia
Analgesia
Paresthesia
Which endogenous opioid receptor subtype is primarily responsible for analgesia?
Kappa
Delta
Mu
Sigma
Which of the following best describes neuropathic pain?
Pain from tissue damage and inflammation
Pain due to lesion or dysfunction in the somatosensory nervous system
Pain caused by psychological factors only
Pain arising solely from muscle spasms
The "wind-up" phenomenon refers to:
Decreased pain sensitivity after repeated stimuli
Progressive increase in dorsal horn neuron excitability after repetitive stimulation
Inhibition of pain transmission by A-beta fibers
Release of endogenous opioids during stress
The primary function of the Na⁺/K⁺ ATPase pump is to:
Transport sodium and potassium passively
Maintain the resting membrane potential by actively transporting ions
Facilitate endocytosis
Synthesize ATP
Which organelle is responsible for synthesizing most cellular ATP?
Golgi apparatus
Lysosome
Mitochondrion
Ribosome
The phase of the cell cycle where DNA replication occurs is:
G0
G1
S phase
M phase
Which type of cell junction allows direct cytoplasmic communication between adjacent cells?
Tight junction
Gap junction
Desmosome
Hemidesmosome
In receptor-mediated endocytosis, the receptor-ligand complexes are internalized by:
Phagocytosis
Pinocytosis
Clathrin-coated pits
Exocytosis
Which of the following molecules pass most freely through the plasma membrane without a transporter?
Glucose
Sodium ions
Oxygen
Amino acids
The resting membrane potential is typically closest to:
+60 mV
-70 mV
0 mV
-120 mV
Which cytoskeletal component provides structural support and resists tension?
Microtubules
Intermediate filaments
Microfilaments
Actin
Protein synthesis occurs primarily at the:
Smooth endoplasmic reticulum
Rough endoplasmic reticulum
Golgi apparatus
Mitochondria
Which phase of mitosis involves chromosome alignment at the cell's equator?
Prophase
Metaphase
Anaphase
Telophase
The primary role of lysosomes is:
ATP production
Protein synthesis
Digestion of cellular waste and foreign material
Lipid synthesis
Which of the following is a second messenger involved in signal transduction?
cAMP
DNA
ATP
NADH
Osmosis is the movement of water across a semipermeable membrane from:
Low solute concentration to high solute concentration
High solute concentration to low solute concentration
Areas of high pressure to low pressure
Areas of low water concentration to high water concentration
Which enzyme is responsible for breaking down ATP to provide energy in cells?
Kinase
ATPase
Ligase
Polymerase
The endoplasmic reticulum is involved in:
Protein and lipid synthesis
DNA replication
Cellular respiration
Intracellular digestion
The primary pacemaker of the heart is located in the:
Atrioventricular node
Sinoatrial node
Purkinje fibers
Bundle of His
The primary function of bile salts in digestion is to:
Neutralize stomach acid
Emulsify dietary fats to increase surface area for lipase action
Absorb vitamins B12 and K
Stimulate pancreatic enzyme secretion
Which segment of the small intestine is the MAIN site of nutrient absorption?
Duodenum
Cecum
Ileum
Jejunum
During the cephalic phase of digestion, which of the following occurs?
Activation of vagus nerve stimulating gastric secretions
Gastric emptying slows down
Increased pancreatic bicarbonate secretion via secretin
Release of cholecystokinin to relax the sphincter of Oddi
Which digestive enzyme is responsible for breaking down starch into maltose?
Pepsin
Lactase
Lipase
Amylase
The intrinsic factor secreted by the stomach is essential for:
Iron absorption in the duodenum
Calcium absorption in the jejunum
Vitamin B12 absorption in the ileum
Protein digestion in the stomach
Which of the following BEST describes the function of secretin?
Stimulates pancreatic bicarbonate secretion to neutralize gastric acid
Stimulates gastric acid secretion
Stimulates bile release from the gallbladder
Stimulates appetite
Which hormone regulates blood calcium levels by increasing osteoclastic activity?
Calcitonin
Insulin
Aldosterone
Parathyroid hormone (PTH)
During inspiration, the diaphragm:
Relaxes and moves upward
Contracts and moves downward
Relaxes and moves downward
Contracts and moves upward
The primary buffer system in the blood is:
Bicarbonate buffer
Protein buffer
Phosphate buffer
Sulfate buffer
The functional unit of the kidney is the:
Collecting duct
Loop of Henle
Nephron
Glomerulus
Which blood vessel layer contains smooth muscle?
Tunica intima
Tunica media
Tunica adventitia
Endothelium
In skeletal muscle contraction, which ion initiates the interaction between actin and myosin?
Potassium
Calcium
Chloride
Sodium
The hormone that increases glucose uptake by cells is:
Glucagon
Insulin
Cortisol
Epinephrine
The portion of the nervous system responsible for “rest and digest” functions is the:
Parasympathetic nervous system
Sympathetic nervous system
Somatic nervous system
Enteric nervous system
Which of the following is the main gas exchanged in the alveoli?
Nitrogen
Carbon dioxide
Hydrogen
Oxygen
The osmotic pressure of plasma is mainly due to:
Plasma proteins (albumin)
Lipids
Electrolytes
Glucose
The primary effect of aldosterone on the kidney is to:
Increase sodium reabsorption
Increase potassium reabsorption
Decrease water reabsorption
Increase glucose reabsorption
The sensory receptor for detecting stretch in muscles is the:
Golgi tendon organ
Pacinian corpuscle
Ruffini ending
Muscle spindle
Which blood component is primarily responsible for oxygen transport?
Plasma
Hemoglobin erythrocytes
Leukocytes
Platelets
The Frank-Starling law of the heart states that:
Increased venous return leads to decreased cardiac output
Increased stretch of ventricular muscle fibers leads to increased force of contraction
Heart rate decreases with increased preload
Stroke volume is independent of end-diastolic volume
