Homeostasis + Water Balance
Which of the following best defines homeostasis?
A) The process by which the body stores energy for later use.
B) The ability of the body to maintain stable internal conditions despite external changes.
C) The regulation of body temperature through sweating and shivering.
D) The movement of molecules across cell membranes.
B) The ability of the body to maintain stable internal conditions despite external changes.
Which of the following best describes the function of afferent neurons?
A) They transmit signals from the brain to muscles for voluntary movement.
B) They carry sensory information from the body to the central nervous system.
C) They release neurotransmitters at synapses.
D) They help in the formation of myelin sheath around axons.
B) They carry sensory information from the body to the central nervous system.
Which of the following correctly contrasts exocrine and endocrine glands?
A) Exocrine glands secrete their products into the bloodstream, while endocrine glands secrete their products into ducts.
B) Exocrine glands secrete their products into ducts, and endocrine glands release hormones directly into the bloodstream.
C) Exocrine glands release hormones into the bloodstream, and endocrine glands secrete enzymes onto body surfaces.
D) Both exocrine and endocrine glands release products into the bloodstream.
B) Exocrine glands secrete their products into ducts, and endocrine glands release hormones directly into the bloodstream.
Explanation: Exocrine glands use ducts to secrete substances like enzymes, while endocrine glands release hormones into the bloodstream, influencing distant target cells.
Which of the following is a key difference between pulmonary circulation and systemic circulation?
A) Pulmonary circulation carries oxygen-rich blood from the heart to the body, while systemic circulation carries oxygen-poor blood to the lungs.
B) Pulmonary circulation carries oxygen-poor blood from the heart to the lungs, while systemic circulation carries oxygen-rich blood to the body.
C) Pulmonary circulation involves the left side of the heart, while systemic circulation involves the right side of the heart.
D) Pulmonary circulation carries deoxygenated blood to the kidneys, while systemic circulation transports oxygenated blood to the brain.
B) Pulmonary circulation carries oxygen-poor blood from the heart to the lungs, while systemic circulation carries oxygen-rich blood to the body.
Explanation: Pulmonary circulation sends blood to the lungs for oxygenation, while systemic circulation delivers oxygenated blood from the heart to the rest of the body.
Which of the following are examples of pathogens that commonly interact with the human body?
A) Skin cells and muscle tissue
B) Bacteria, viruses, fungi, and parasites
C) Red blood cells and white blood cells
D) Antibodies and antigens
B) Bacteria, viruses, fungi, and parasites
Explanation: Pathogens are harmful microorganisms or agents, including bacteria, viruses, fungi, and parasites, that can cause disease.
Which of the following is an example of negative feedback in the body?
A) The release of insulin to decrease blood glucose after eating.
B) The increase in uterine contractions during labor, which leads to more contractions.
C) The production of milk in response to infant suckling.
D) The increase in heart rate during exercise.
A) The release of insulin to decrease blood glucose after eating.
Explanation: Negative feedback works to reverse or negate a change, like lowering blood sugar. Positive feedback amplifies a change, like contractions during labor.
Which of the following pairs of systems are responsible for controlling involuntary functions such as heart rate and digestion?
A) Somatic nervous system and central nervous system.
B) Autonomic nervous system and peripheral nervous system.
C) Sympathetic nervous system and parasympathetic nervous system.
D) Central nervous system and sympathetic nervous system.
C) Sympathetic nervous system and parasympathetic nervous system.
Explanation: The sympathetic and parasympathetic divisions of the autonomic nervous system regulate involuntary functions such as heart rate, digestion, and respiratory rate.
Which of the following is a key difference between the nervous and endocrine systems?
A) The nervous system uses hormones to communicate, while the endocrine system uses electrical impulses.
B) The nervous system has a faster, short-term response, while the endocrine system has a slower, longer-lasting effect.
C) The nervous system is slower but longer-lasting than the endocrine system.
D) Both systems communicate using the same means and have the same speed of response.
B) The nervous system has a faster, short-term response, while the endocrine system has a slower, longer-lasting effect.
Explanation: The nervous system uses electrical impulses for quick, short-term communication, while the endocrine system uses hormones for slower but longer-lasting effects.
Which of the following heart valves prevents the backflow of blood from the aorta into the left ventricle?
A) Tricuspid valve
B) Mitral valve
C) Pulmonary valve
D) Aortic valve
D) Aortic valve
Explanation: The aortic valve prevents backflow of blood from the aorta into the left ventricle after it has been pumped out of the heart.
Which of the following is a key difference between the innate and adaptive immune systems?
A) The innate immune system responds slowly and specifically, while the adaptive immune system is fast and nonspecific.
B) The innate immune system is a rapid, nonspecific defense, while the adaptive immune system is slower but highly specific and can "remember" pathogens.
C) The adaptive immune system is made up of physical barriers like skin, while the innate system includes antibodies.
D) The innate immune system only involves B cells, while the adaptive immune system only involves T cells.
B) The innate immune system is a rapid, nonspecific defense, while the adaptive immune system is slower but highly specific and can "remember" pathogens.
Explanation: The innate immune system provides a general, immediate response to pathogens, while the adaptive immune system is slower, more specific, and capable of developing long-term immunity through memory cells.
Which of the following is the primary function of the kidneys?
A) To produce insulin and regulate blood sugar levels.
B) To filter blood, remove waste, and maintain electrolyte balance.
C) To store bile for digestion.
D) To produce red blood cells and maintain immunity.
B) To filter blood, remove waste, and maintain electrolyte balance.
Which of the following brain structures is primarily responsible for regulating emotions and forming memories?
A) Medulla oblongata
B) Thalamus
C) Limbic system
D) Corpus callosum
C) Limbic system.
Explanation: The limbic system is involved in emotions, memory, and arousal. It includes structures like the amygdala and hippocampus.
Which hormone is secreted by the posterior pituitary gland and is responsible for regulating water balance by increasing water reabsorption in the kidneys?
A) Oxytocin
B) Growth hormone
C) Antidiuretic hormone (ADH)
D) Prolactin
C) Antidiuretic hormone (ADH)
Explanation: ADH, released from the posterior pituitary, increases water reabsorption in the kidneys, helping to maintain water balance and homeostasis.
In which chamber of the heart is the blood most oxygen-rich, and from which chamber does it leave to be pumped to the body?
A) Right atrium, pumped out through the pulmonary artery
B) Left atrium, pumped out through the aorta
C) Right ventricle, pumped out through the aorta
D) Left ventricle, pumped out through the pulmonary artery
B) Left atrium, pumped out through the aorta
Explanation: Oxygen-rich blood from the lungs enters the left atrium, then flows into the left ventricle, from where it is pumped through the aorta to the body.
How do inflammation and fever aid the innate immune system in fighting pathogens?
A) They increase blood flow to tissues and enhance the action of immune cells by raising body temperature.
B) They decrease blood flow to infected tissues, preventing the spread of pathogens.
C) They reduce the activity of white blood cells to prevent immune overreaction.
D) They help produce antibodies that target specific pathogens.
A) They increase blood flow to tissues and enhance the action of immune cells by raising body temperature.
Explanation: Inflammation helps deliver immune cells to the site of infection, and fever raises body temperature, which can inhibit pathogen growth and enhance immune response.
How do kidneys efficiently filter blood?
A) Blood flows through the glomerulus where water and small solutes are filtered into the Bowman's capsule, while larger molecules like proteins and blood cells remain in the bloodstream.
B) Blood is filtered through the renal artery and directly into the renal pelvis.
C) The kidney uses active transport to move toxins into the bloodstream for excretion.
D) The glomerular filtration rate is independent of blood pressure and volume.
A) Blood flows through the glomerulus where water and small solutes are filtered into the Bowman's capsule, while larger molecules like proteins and blood cells remain in the bloodstream.
Which of the following sequences represents the correct order of components in a reflex arc?
A) Sensory receptor → Interneuron → Motor neuron → Effector → Brain
B) Sensory receptor → Motor neuron → Interneuron → Brain → Effector
C) Sensory receptor → Sensory neuron → Interneuron → Motor neuron → Effector
D) Effector → Motor neuron → Sensory neuron → Interneuron → Sensory receptor
C) Sensory receptor → Sensory neuron → Interneuron → Motor neuron → Effector.
Explanation: In a reflex arc, sensory receptors detect a stimulus, sensory neurons transmit it to the spinal cord, interneurons process the signal, motor neurons carry the response, and effectors (e.g., muscles) carry out the action.
Which of the following correctly matches the hormone with its function and the gland that produces it?
A) Calcitonin (CT) – increases blood calcium levels; secreted by the thyroid gland.
B) Parathyroid hormone (PTH) – decreases blood calcium levels; secreted by the parathyroid glands.
C) Thyroid hormone (TH) – increases metabolic rate and growth; secreted by the thyroid gland.
D) Calcitonin (CT) – increases calcium release from bones; secreted by the parathyroid glands.
C) Thyroid hormone (TH) – increases metabolic rate and growth; secreted by the thyroid gland.
Explanation: TH regulates metabolism and growth. Calcitonin lowers blood calcium, and PTH increases blood calcium.
How does the pacemaker (SA node) of the heart control the heartbeat, and how do systole and diastole differ?
A) The pacemaker generates electrical impulses that trigger heart contraction during systole, and the heart relaxes during diastole.
B) The pacemaker generates electrical impulses that trigger heart relaxation during systole, and contraction during diastole.
C) Systole is the phase of heart relaxation, while diastole is when the heart contracts.
D) The pacemaker generates electrical impulses to relax the heart during systole and contract it during diastole.
A) The pacemaker generates electrical impulses that trigger heart contraction during systole, and the heart relaxes during diastole.
Explanation: The pacemaker (SA node) initiates electrical impulses, causing the heart to contract during systole (the contraction phase), while the heart relaxes during diastole (the relaxation phase).
Which of the following immune cells is responsible for directly killing infected cells and cancer cells?
A) Helper T cells
B) Cytotoxic T cells
C) B cells
D) Phagocytes
B) Cytotoxic T cells
Explanation: Cytotoxic T cells, also known as killer T cells, directly target and destroy infected cells or cancer cells. Helper T cells assist other immune cells, B cells produce antibodies, and phagocytes engulf pathogens.
Which of the following hormones is involved in regulating kidney function and blood pressure, and what is its effect?
A) Renin – increases urine production and lowers blood pressure.
B) Antidiuretic hormone (ADH) – decreases urine production, increasing water reabsorption and raising blood pressure.
C) Aldosterone – decreases sodium reabsorption, lowering blood volume.
D) Erythropoietin – decreases red blood cell production and lowers blood volume.
B) Antidiuretic hormone (ADH) – decreases urine production, increasing water reabsorption and raising blood pressure.
Explanation: ADH promotes water retention in the kidneys, which helps increase blood volume and pressure. Renin and aldosterone also contribute to blood pressure regulation, while erythropoietin affects red blood cell production.
Which of the following is true about action potentials?
A) They are triggered by the rapid influx of potassium ions during depolarization.
B) The sodium-potassium pump is responsible for creating the action potential, by allowing sodium ions into the axon.
C) Action potentials are consistent in magnitude and irreversible once initiated, regardless of the stimulus strength.
D) Myelination slows the speed of action potentials by increasing the number of action potentials fired.
C) Action potentials are consistent in magnitude and irreversible once initiated, regardless of the stimulus strength.
Explanation: Once an action potential is triggered, it is always of the same size and cannot be stopped. Myelination speeds up action potential conduction by allowing the signal to jump between nodes of Ranvier.
Which of the following hormones are released by the adrenal medulla during the "fight or flight" response, and what is their primary effect?
A) Epinephrine and norepinephrine – they increase heart rate, blood pressure, and blood flow to muscles.
B) Aldosterone and cortisol – they increase glucose uptake and decrease heart rate.
C) Insulin and glucagon – they regulate blood glucose by decreasing blood sugar.
D) Thyroid hormone and calcitonin – they regulate metabolism and calcium levels
A) Epinephrine and norepinephrine – they increase heart rate, blood pressure, and blood flow to muscles.
Explanation: Epinephrine and norepinephrine, secreted by the adrenal medulla, prepare the body for stress by increasing heart rate, blood pressure, and redirecting blood flow to essential areas like muscles.
Which of the following blood vessels has the thickest muscular wall, contains no valves, and carries oxygen-rich blood from the heart to the tissues?
A) Veins
B) Capillaries
C) Arteries
D) Venules
C) Arteries
Explanation: Arteries have thick muscular walls to withstand the high pressure from the heart's pumping action. They carry oxygen-rich blood (except for the pulmonary arteries) from the heart to the tissues. They do not have valves because the pressure is sufficient to keep blood flowing in one direction.
How does the adaptive immune system "remember" a pathogen, and how does this modify the immune response during a second exposure?
A) Memory B cells store the pathogen's antibodies, which are produced again during secondary exposure.
B) Memory T cells destroy the pathogen faster during a secondary exposure.
C) The innate immune system "learns" pathogens, speeding up its initial response.
D) Antigens are stored in the body, triggering a rapid immune response when re-exposed.
A) Memory B cells store the pathogen's antibodies, which are produced again during secondary exposure.
Explanation: Memory B cells remember the pathogen's antigens and allow the immune system to produce a faster and stronger antibody response during a second exposure, providing immunity.