Exam Flashcards
What is the source of ATP for muscle contraction and relaxation?
Creatine phosphate, glycolysis, and oxidative phosphorylation
ATP is supplied by three main sources: creatine phosphate provides a rapid supply, glycolysis generates ATP quickly under anaerobic conditions, and oxidative phosphorylation occurs in mitochondria under aerobic conditions.
Which statement regarding the normal functioning of the human biological clock is correct?
Melatonin levels are normally low in daylight, but rise significantly during darkness
Melatonin is produced by the pineal gland and helps regulate sleep-wake cycles.
What does the thyroid gland regulate?
The body’s metabolic rate and growth
The thyroid produces hormones like thyroxine (T4) and triiodothyronine (T3) that influence metabolism and growth.
Involuntary breathing is controlled by which part of the brain?
Neurons in the pons and the medulla
The medulla generates the basic rhythm of breathing, while the pons modifies it for smooth breathing.
What is the correct path that oxygen takes after it enters the trachea?
Bronchi → Bronchioles → Alveoli → Pulmonary capillaries
Oxygen travels through the trachea, bronchi, bronchioles, and reaches alveoli for gas exchange before entering pulmonary capillaries.
Which bones develop by endochondral ossification?
Long bones
Long bones like the femur and tibia develop from a cartilage model through endochondral ossification.
Which cell type is multinucleated and involved in bone resorption?
Osteoclast
Osteoclasts break down bone tissue by secreting acids and enzymes, crucial for bone remodeling.
Which substance should be filtered by the glomerulus?
Creatinine
Creatinine is a waste product from muscle metabolism and is small enough to be filtered by the glomerulus.
Which factor decreases glomerular filtration rate (GFR)?
Vasoconstriction of afferent arteriole
This reduces blood flow into the glomerulus, lowering pressure and GFR.
How is the pulmonary circulation characterized?
Low pressure, high flow
The pulmonary circulation has lower pressure than systemic circulation but a high flow rate for oxygenation.
What do arterial endothelial cells express?
EphrinB2
EphrinB2 is important for vascular development and is specifically expressed by arterial endothelial cells.
What is the tenth cranial nerve called?
Vagus
The vagus nerve carries a large portion of the parasympathetic nerve fibers, innervating various organs.
Administration of a muscarinic receptor agonist would:
Reduce heart rate
Muscarinic receptors are part of the parasympathetic nervous system, and their activation mimics acetylcholine effects.
What is the typical effect of muscarinic receptor activation on heart rate?
Reduces heart rate (bradycardia)
Muscarinic receptors are part of the parasympathetic nervous system and their activation leads to ‘rest and digest’ functions.
Which hormones are produced by both the adrenal glands and the gonads?
Androstendione and testosterone
Androstendione is a precursor to testosterone and estrone, produced in both the adrenal glands and gonads.
Which tissues assist in testicular thermoregulation?
Dartos muscle and pampiniform plexus
The dartos muscle adjusts the position of the testes, while the pampiniform plexus cools the arterial blood entering the testes.
What stimulates the release of the intestinal hormone secretin?
Acid in the duodenum
Secretin is released in response to low pH in the duodenum to help neutralize stomach acid.
Carbohydrates are absorbed as:
Monosaccharides
Carbohydrates are broken down into glucose, fructose, and galactose during digestion.
Which statement is true about the innate immune response?
Involves complement which when activated can form the membrane attack complex
The innate immune response is the first line of defense and is not specific to pathogens.
Which statement relates to when the immune system is not working properly?
Anaphylactic reactions triggered by antigen-antibody complexes
Anaphylaxis is an overreaction of the immune system to harmless substances, leading to severe allergic reactions.
True or False: B cell receptors can recognize antigens with a high degree of specificity in the innate immune response.
False
This specificity is characteristic of the adaptive immune response, not the innate immune response.
Fill in the blank: The _______ muscle helps regulate testicular temperature by adjusting the position of the testes.
dartos
The dartos muscle contracts or relaxes based on temperature.
What does secretin stimulate in the pancreas?
Release of bicarbonate-rich fluid
This neutralizes the acid entering the duodenum from the stomach.
True or False: The innate immune response has memory and reacts faster upon subsequent infections.
False
Memory is a characteristic of the adaptive immune response.
