30 Questions
What is the main function of the endoplasmic reticulum (ER)?
To make lipids and proteins for the cell's membranes and proteins for secretion
What is the main function of lysosomes?
To break down particles like cellular debris and waste
What is the main component of peroxisomes?
Enzymes that break down organic molecules
What is the function of the smooth endoplasmic reticulum (SER) in liver cells?
To release glucose from glycogen
What is the main difference between the rough endoplasmic reticulum (RER) and the smooth endoplasmic reticulum (SER)?
The RER has ribosomes attached to it, while the SER does not
What is the pH of the interior of lysosomes compared to the rest of the cytoplasm?
More acidic (near pH 5)
What happens at the end of the refractory period?
The potassium channels close and the resting period is reestablished
What is the main difference between action potentials in muscle cells and neurons?
Muscle cells require a stronger depolarization to reach the threshold
What happens when the membrane potential increases enough to reach the threshold?
The voltage-gated sodium channels and sarcolemma open
What is the main difference between the action potential in muscle cells and heart cells?
Muscle cells are triggered by a transmitter, while heart cells are triggered by electrochemical stimulation
What is the role of chloride channels in muscle cell action potentials?
They open to stabilize the membrane potential
Why is the refractory period short in muscle cells?
To allow for quick muscle contractions
What serves as the cardiac pacemaker in the heart?
Sinoatrial node
Where is the atrioventricular (AV) node located?
In the middle of the heart
Which electrolyte moves out of the cell during cardiac muscle contraction?
Sodium
What is the main role of Purkinje's fibers in the heart?
To transmit electrical impulses through the heart
Which structure separates the left and right ventricles in the heart?
Interventricular septum
What triggers depolarization and contraction in the ventricles of the heart?
Action potential from SA node
What is the primary function of hemoglobin in the transport of oxygen?
To bind oxygen molecules for transport in red blood cells
How does a decrease in pH affect the affinity of hemoglobin for oxygen?
It decreases the affinity of hemoglobin for oxygen
Which of the following statements about fetal hemoglobin is true?
It has a higher affinity for binding oxygen compared to adult hemoglobin
What is the primary role of carbonic anhydrase in the transport of carbon dioxide?
To catalyze the formation of carbonic acid from carbon dioxide and water
What happens to bicarbonate ions (HCO3-) produced in red blood cells during the transport of carbon dioxide?
They are transported out of the red blood cells
What happens to oxygen binding to hemoglobin when there is a high concentration of carbon dioxide?
Less oxygen binds to hemoglobin
What is the primary function of antidiuretic hormone (ADH) in regulating urine volume?
It increases the permeability of the distal tubule and collecting ducts to water, leading to more concentrated urine.
What is the role of the renin-angiotensin-aldosterone system (RAAS) in regulating blood pressure and fluid balance?
It increases sodium and water reabsorption in the kidneys, leading to increased blood volume and blood pressure.
What is the primary function of the central nervous system?
It is responsible for processing sensory information and initiating motor responses.
Which of the following statements about the renin-angiotensin-aldosterone system (RAAS) is correct?
Angiotensin II causes vasoconstriction of blood vessels and stimulates the release of aldosterone.
What is the primary function of the brain in the central nervous system?
It is responsible for processing sensory information and coordinating higher cognitive functions.
What happens when there is an excess of water in the body, leading to a decrease in extracellular fluid osmolarity?
Antidiuretic hormone (ADH) secretion decreases, leading to more dilute urine.
Test your knowledge on the process of action potential in muscle cells, including the opening and closing of ion channels, depolarization, and the role of neurotransmitters like acetylcholine.
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