Reflexes and Cell Junctions

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Where does erythropoiesis primarily occur in the body?

Red bone marrow (correct)

Renal cortex

Renal medulla

Descending Loop of Henle

Which part of the nephron is responsible for reabsorption of Na+ and Cl- from the filtrate into the interstitial fluid?

Loop of Henle (correct)

Glomerulus

Proximal tubules (PCT)

Collecting duct

What is the main function of the collecting duct in the kidney?

Secretion of ions to maintain blood pH

Filtration of small solutes from the blood

Production of erythrocytes

Reabsorption of water and solutes (correct)

What is the role of plasma in the body?

Contains clotting factors Signup and view all the answers

Which hormone upregulates aquaporins in collecting ducts to increase water reabsorption into the bloodstream?

Aldosterone Signup and view all the answers

What is the function of the descending Loop of Henle in the kidney?

Reabsorb water via aquaporins Signup and view all the answers

Where do megakaryocytes primarily fragment to create platelets?

Red bone marrow Signup and view all the answers

What happens in leukopoiesis?

Production of white blood cells Signup and view all the answers

What is the main function of tight junctions between adjacent epithelial cells?

Prevent the leakage of small molecules and ions Signup and view all the answers

Which reflex involves the spreading of a baby's toes and lifting of its big toe when the sole is stimulated?

Babinski reflex Signup and view all the answers

What is the function of hemidesmosomes in cells?

Connect cells to the extracellular matrix Signup and view all the answers

Which enzyme is responsible for relieving the overwinding of DNA strands during replication by breaking, swiveling, and rejoining DNA strands?

Topoisomerase Signup and view all the answers

What type of immunity involves dendritic cells that are specialized immune cells found in the skin and mucous membranes?

Adaptive immunity Signup and view all the answers

Which reflex is characterized by the baby's head moving toward an object that stimulates its mouth and cheeks?

Rooting reflex Signup and view all the answers

What is the main role of ribosomes in a cell?

Protein synthesis Signup and view all the answers

Which enzyme binds two DNA fragments together by phosphodiester bonds during DNA replication?

Ligase Signup and view all the answers

What would be the primary consequence of a deficiency in antidiuretic hormone (ADH)?

Excessive water loss and increased thirst Signup and view all the answers

If aldosterone levels are low, what would be the expected outcome?

Decreased sodium reabsorption in the kidneys Signup and view all the answers

Which of the following statements accurately describes the relationship between blood pressure, filtration, and reabsorption?

Increased blood pressure increases both filtration and reabsorption Signup and view all the answers

Which condition is characterized by an excess of fluid in the blood plasma?

Hypervolemia Signup and view all the answers

Which division of the nervous system is responsible for the involuntary control of gastrointestinal functioning?

Enteric nervous system Signup and view all the answers

Which division of the nervous system is associated with voluntary control of body movements through stimulation of the skeletal muscles?

Somatic nervous system Signup and view all the answers

Which characteristic distinguishes the parasympathetic nervous system from the sympathetic nervous system?

The parasympathetic nervous system has longer preganglionic fibers and shorter postganglionic fibers Signup and view all the answers

What is the primary function of the sympathetic nervous system as described in the given information?

Increasing various physiological processes in response to danger or stress Signup and view all the answers

What is the primary function of goblet cells in the respiratory tract?

Produce mucus to trap foreign particles Signup and view all the answers

Which type of mutation involves the inversion of a chromosomal segment?

Inversion mutation Signup and view all the answers

Which type of mutation is most likely to accumulate in a species over time through natural selection?

Beneficial mutations Signup and view all the answers

What is the primary function of dendrites in neurons?

Receive action potentials from other neurons Signup and view all the answers

What is the role of myelin sheaths in axons?

Prevent signal loss by insulating the axon Signup and view all the answers

What is the primary function of nodes of Ranvier in myelinated axons?

Allow action potentials to travel quickly through the axon Signup and view all the answers

Which step occurs first in the process of neurotransmission?

Release of neurotransmitters from the presynaptic membrane Signup and view all the answers

Which type of mutation involves a change from a purine nucleotide to a pyrimidine nucleotide, or vice versa?

Transversion mutation Signup and view all the answers

What is the primary function of phosphodiesterase in the cAMP signaling pathway?

To catalyze the cleavage of cAMP to AMP, restoring baseline levels of cAMP Signup and view all the answers

Which of the following statements about positive feedback loops is true?

They encourage deviations from the mean value by amplifying the initial signal Signup and view all the answers

Which of the following statements about the resting membrane potential and action potential initiation is correct?

The resting membrane potential of a neuron is typically around -70mV Signup and view all the answers

Which of the following statements accurately describes the all-or-none phenomenon in action potential generation?

Both threshold and suprathreshold stimuli produce action potentials of the same magnitude Signup and view all the answers

What is the primary mechanism by which summation of impulses occurs in neurons?

Both temporal and spatial summation contribute to the summation of impulses Signup and view all the answers

What is the primary function of myelin sheaths in neurons?

To allow for the saltatory conduction of action potentials Signup and view all the answers

What is the likely effect of increased expression of NMDA receptors in the hippocampus?

Increased likelihood of action potential formation, increasing excitability Signup and view all the answers

Which of the following statements accurately describes negative feedback loops?

They help maintain homeostasis by inhibiting deviations from the mean value Signup and view all the answers