NT
A drug increases serotonin signaling. The animal subsequently shows changes in sleep-wake behavior, appetite, mood, and pain sensitivity, without directly causing skeletal muscle contraction. Which neurotransmitter is being affected?
A. GABA
B. Acetylcholine
C. Serotonin
C. Serotonin
Which leukocyte is particularly associated with defence against parasites and allergic reactions?
A. Monocyte
B. Eosinophil
C. Neutrophil
B. Eosinophil
Most plasma proteins, including albumin and fibrinogen, are synthesized primarily by which organ?
A. Kidney
B. Liver
C. Spleen
B. Liver
Which chamber receives deoxygenated blood returning from systemic circulation?
A. Left atrium
B. Right atrium
C. Left ventricle
B. Right atrium
A frightened horse develops tachycardia and increased alertness. Which combination best explains these changes?
A. Increased sympathetic activity and increased norepinephrine
B. Increased parasympathetic activity and increased GABA
C. Decreased sympathetic activity and increased acetylcholine
A. Increased sympathetic activity and increased norepinephrine
Which neurotransmitter is important for parasympathetic signaling, including slowing heart rate?
A. Acetylcholine
B. Dopamine
C. Glutamate
A. Acetylcholine
Which leukocyte is typically an important first responder during acute inflammation?
A. Neutrophil
B. Eosinophil
C. Lymphocyte
A. Neutrophil
Which is the most abundant plasma protein?
A. Albumin
B. Fibrinogen
C. Serum Amyloid-A
A. Albumin
Which vessel carries deoxygenated blood from the right ventricle toward the lungs?
A. Pulmonary artery
B. Pulmonary vein
C. Aorta
A. Pulmonary artery
A calf experiences acute stress. Which combination would most likely occur?
A. Decreased heart rate + decreased norepinephrine + decreased N:L ratio
B. Increased heart rate + increased sympathetic activity + increased N:L ratio
C. Decreased heart rate + increased parasympathetic activity + increased N:L ratio
B. Increased heart rate + increased sympathetic activity + increased N:L ratio
In the retina, inhibitory interneurons help create center-surround receptive fields, allowing the visual system to detect differences in light intensity and enhance contrast. Which neurotransmitter is strongly involved?
A. GABA
B. Acetylcholine
C. Serotonin
A. GABA
Which leukocytes can migrate into tissues and differentiate into macrophages?
A. Monocytes
B. Lymphocytes
C. Basophils
A. Monocytes
A horse has severe protein loss through the kidneys. Laboratory testing shows decreased plasma albumin. Which physiological consequence is most likely?
A. Reduced plasma colloid osmotic pressure, favouring movement of fluid from the vascular space into the interstitial space
B. Increased plasma colloid osmotic pressure, promoting movement of fluid from the interstitial space into the tissues
C. Reduced capillary hydrostatic pressure, limiting filtration of fluid into the interstitial space
A. Reduced plasma colloid osmotic pressure, favouring movement of fluid from the vascular space into the interstitial space
Which valve prevents backflow from the left ventricle into the left atrium?
A. Tricuspid valve
B. Pulmonary valve
C. Mitral valve
C. Mitral valve
A dog experiences significant blood loss. Which combination would be expected initially as compensation?
A. Increased sympathetic activity, increased heart rate, and peripheral vasoconstriction
B. Increased parasympathetic activity, decreased heart rate, and peripheral vasodilation
C. Decreased sympathetic activity, decreased heart rate, and increased peripheral vasoconstriction
A. Increased sympathetic activity, increased heart rate, and peripheral vasoconstriction
Which neurotransmitter promotes cortical activation and wakefulness and works with NE in the ascending arousal system?
A. Glutamate
B. Glycine
C. Histamine
C. Histamine
Which leukocytes are most closely associated with adaptive immunity?
A. Neutrophils
B. Lymphocytes
C. Monocytes
B. Lymphocytes
A horse develops acute inflammation following surgery. Which change in plasma proteins would be most consistent with the acute-phase response?
A. Increased albumin concentration with no change in fibrinogen
B. Decreased fibrinogen concentration accompanied by increased albumin concentration
C. Increased fibrinogen concentration accompanied by decreased albumin concentration
A. Increased fibrinogen concentration accompanied by decreased albumin concentration
A horse suddenly stands after prolonged recumbency. Blood pools in the limbs, decreasing venous return. Which response helps compensate?
A. Increased sympathetic activity causing increased heart rate and vasoconstriction
B. Increased parasympathetic activity causing decreased heart rate
C. Peripheral vasodilation increasing venous pooling
A. Increased sympathetic activity causing increased heart rate and vasoconstriction
A dog develops hypoalbuminemia after severe liver dysfunction. Which combination is most likely?
A. ↓ Albumin → ↓ plasma oncotic pressure → increased edema
B. ↑ Albumin → ↓ plasma oncotic pressure → increased edema
C. ↓ Albumin → ↑ plasma oncotic pressure → decreased edema
A. ↓ Albumin → ↓ plasma oncotic pressure → increased edema
A horse receives a sudden, painful stimulus and rapidly withdraws its limb. In the spinal cord, an inhibitory neurotransmitter helps regulate motor neuron activity and prevents excessive neuronal excitation. Which neurotransmitter is primarily responsible?
A. Glycine
B. Acetylcholine
C. Serotonin
A. Glycine
A calf undergoes surgical castration. Several hours later, its CBC shows an increased neutrophil-to-lymphocyte (N:L) ratio. Which explanation is most appropriate?
A. Stress-induced redistribution of leukocytes, resulting in increased circulating neutrophils relative to lymphocytes
B. Acute stimulation of adaptive immunity, resulting in increased circulating lymphocytes
C. Increased erythropoiesis, resulting in a higher proportion of neutrophils in the blood
A. Stress-induced redistribution of leukocytes
A horse has severe inflammation. Laboratory results show increased fibrinogen, increased globulins, and decreased albumin. Which interpretation best explains this plasma-protein profile?
A. An inflammatory response characterized by increased positive acute-phase proteins, increased immune proteins, and decreased negative acute-phase proteins
B. A protein-losing disorder characterized by selective albumin loss, with secondary increases in fibrinogen and globulins compensating for the loss
C. A hepatic synthetic response characterized by increased production of fibrinogen and globulins while albumin concentration decreases because of altered protein metabolism
A. An inflammatory response characterized by increased positive acute-phase proteins, increased immune proteins, and decreased negative acute-phase proteins
A horse develops left-sided heart failure. Blood backs up into the pulmonary circulation, increasing pulmonary capillary hydrostatic pressure. What is the likely consequence?
A. Decreased pulmonary hydrostatic pressure reducing fluid filtration
B. Increased plasma oncotic pressure drawing fluid into pulmonary capillaries
C. Increased movement of fluid into pulmonary interstitial tissue and potentially the alveoli
C. Increased movement of fluid into pulmonary interstitial tissue and potentially the alveoli
A cat encounters a predator. Photoreceptors in the retina detect light, retinal circuits process contrast, and the brain receives the visual information. The horse becomes highly alert and its heart rate increases. Which combination best matches the processes involved?
A. Glutamate in retinal excitation + GABA in retinal inhibition + norepinephrine in central arousal
B. GABA in retinal excitation + glycine in central arousal + acetylcholine in sympathetic activation
C. Dopamine in photoreceptors + enkephalin in retinal inhibition + serotonin in sympathetic activation
A. Glutamate in retinal excitation + GABA in retinal inhibition + norepinephrine in central arousal