Info Flashcards
How is ATP stored and used in muscles?
ATP is stored in muscles but only in small amounts. It is used during short, intense periods of muscle activity. However, ATP is quickly depleted, and other processes must regenerate it.
What are the main pathways for regenerating ATP during muscle contraction?
- Creatine phosphate: Provides a rapid source of ATP by donating phosphate to ADP.
- Glycolysis: A process that breaks down glucose to produce ATP without oxygen (anaerobic).
- Oxidative phosphorylation: A slower process that produces ATP through aerobic respiration in the mitochondria.
How does the crossbridge cycle use ATP?
ATP is necessary for myosin heads to detach from actin filaments and reset for the next contraction. It also powers the power stroke that results in muscle contraction.
Why do muscles need continuous ATP during contraction?
Muscles require ATP to enable the actin and myosin filaments to interact, detach, and reset for continued contraction. Without ATP, muscles would remain contracted and unable to relax.
How does light influence the biological clock?
Light serves as the primary cue for setting the biological clock, adjusting circadian rhythms by signaling the pineal gland to suppress melatonin during daylight.
What role does melatonin play in the biological clock?
Melatonin is secreted by the pineal gland in response to darkness. It helps signal to the body that it’s time for sleep, regulating the sleep-wake cycle.
What is the function of the pineal gland?
The pineal gland produces melatonin, which regulates sleep-wake cycles and influences circadian rhythms, responding to light and dark cycles.
What are the primary functions of thyroid hormones?
Thyroid hormones (T3 and T4) regulate metabolism, influence growth, and control the rate of energy production and consumption in the body.
What happens when thyroid hormone levels are too low?
Hypothyroidism can lead to fatigue, weight gain, cold intolerance, and slowed growth. It can also decrease metabolism.
What happens when thyroid hormone levels are too high?
Hyperthyroidism can cause weight loss, heat intolerance, increased heart rate, and nervousness due to an overactive metabolism.
What is the difference between the innate and adaptive immune systems?
The innate immune system provides a general, non-specific defense against pathogens. The adaptive immune system is highly specific and adapts to recognize and remember specific pathogens through T and B cells.
What role do B cells play in immunity?
B cells produce antibodies that specifically recognize antigens, marking them for destruction by other immune cells. They are an essential part of the adaptive immune response.
What role do T cells play in immunity?
T cells, including cytotoxic T cells, help destroy infected cells, and helper T cells assist in activating B cells and other immune cells.
What is immune memory?
Immune memory is the ability of the adaptive immune system to remember past infections, allowing for a faster and more efficient response if the pathogen is encountered again. This is mainly facilitated by memory B and T cells.
What is the function of the complement system in immunity?
The complement system consists of proteins that, when activated, can destroy pathogens directly by forming a membrane attack complex (MAC) or by tagging them for destruction by immune cells (opsonization).
How do cytotoxic T cells help in cancer defense?
Cytotoxic T cells recognize and kill cancer cells that display abnormal antigens through MHC class I molecules on their surface.
What causes anaphylactic reactions?
Anaphylactic reactions are severe allergic responses triggered by antigen-antibody complexes that lead to the release of histamines and other chemicals, causing inflammation and constriction of airways.
How is blood pressure regulated by the body?
Blood pressure is regulated by the balance of cardiac output, blood volume, and vascular resistance. The kidneys, heart, and blood vessels work together to maintain normal blood pressure.
How do the testes maintain an optimal temperature for sperm production?
The dartos muscle adjusts the scrotum’s position, and the pampiniform plexus cools blood entering the testes to maintain an ideal temperature for sperm production.
What is the function of the pampiniform plexus?
The pampiniform plexus is a network of veins around the testicular artery that helps cool the blood entering the testes, maintaining a lower temperature essential for sperm production.
How does the dartos muscle contribute to thermoregulation in the testes?
The dartos muscle contracts or relaxes to raise or lower the scrotum, thus regulating the temperature of the testes to support healthy sperm production.
How is blood pH maintained within a narrow range?
Blood pH is maintained by buffering systems, particularly the bicarbonate buffer system, and by the respiratory and renal systems, which can remove excess acids or bases from the blood.
What is the nature of blood flow in pulmonary circulation?
Pulmonary circulation is low pressure, high flow because it delivers blood to the lungs for oxygenation, with low resistance and high volume.
Which hormones influence blood pressure regulation?
- Renin
- Aldosterone
- Antidiuretic hormone (ADH)
