Human Physiology - Chemical Coordination Questions and Answers

When a stimulus is reinforced to continue in the same direction until a climactic event occurs, it is best as described as which of the following? Positive feedback Negative feedback

Physiological responses to stress include activation of the: autonomic nervous system which secretes the hormone cortisol. HPA axis, which is crucially involved in chronic stress. autonomic nervous system which secretes the hormone ACTH. HPA axis, which reacts more quickly than the autonomic nervous system.

The signal that directs proton pumps to the lysosome is Select an answer and submit. For keyboard navigation, use the up/down arrow keys to select an answer. a KDEL b mannose 6 phosphate c ubiquitin d no signal (just bulk transport) e aggregation with other pumps

Carefully read these sentences from paragraph 9 of the article. Based on the context clues, choose the correct meaning for the word stimulation. All this stimulation can get exhausting. Some synesthetes report tiring easily from what they call "sensory overload." Yet most seem to treasure the condition. hard work through intensive effort excitement or increased activity appreciation for something of great worth a wearing down or loss of energy

Arthur Dent, a 28 year old man living in Wokingham attended an outpatient clinic with his wife. He had noticed gradually worsening tiredness and fatigability making his job difficult to maintain. He had gained weight (approx 3kg) and his wife had noticed that he had started wearing an extra thick sweater during the relatively mild winter months His feet had been cold in bed and his hair and skin dry. His wife had to take time off work to bring her husband to the clinic (because Arthur's car was being repaired following damage to both the near- and off-side wings) and she was naturally keen to see things sorted out quickly. Blood tests showed that serum TSH levels were lower than normal while serum T4 levels were very low. Thyroid auto-antibody tests were negative. What endocrine condition is Arthur probably suffering from? A. Primary hyperthyroidism B. Primary hypothyroidism C. Secondary hyperthyroidism D. Secondary hypothyroidism E. Euthyroidism

3. The endocrine system incorporates feedback mechanisms that maintain homeostasis. Which of the following demonstrates negative feedback by the endocrine system? a. During labor, the fetus exerts pressure on the uterine wall, inducing the production of oxytocin, which stimulates uterine wall contraction. The contractions cause the fetus to further push on the wall, increasing the production of oxytocin. b. After a meal, blood glucose levels become elevated, stimulating beta cells of the pancreas to release insulin into the blood. Excess glucose is then converted to glycogen in the liver, reducing blood glucose levels. c. At high elevation, atmospheric oxygen is more scarce. In response to signals that oxygen is low, the brain decreases an individual's rate of respiration to compensate for the difference. d. A transcription factor binds to the regulatory region of a gene, blocking the binding of another transcription factor required for expression.

Thyroxin is a hormone that increases metabolic activities within various tissue targets. Low levels of circulating thyroxin trigger the secretion of thyroid-stimulating hormone (TSH) from the anterior pituitary. TSH secretion then stimulates thyroxin production and release by the thyroid gland. The increased level of circulating thyroxin inhibits further secretion of TSH from the anterior pituitary. Based on the information provided, which of the following can most likely be concluded about the TSH-thyroxin loop? a. A person taking thyroxin to supplement low thyroxin secretion will produce more TSH. b. Increased thyroxin production would cause elevated ribosomal activity in the anterior pituitary. c. The structure of the loop would lead to elevated thyroid and tissue activity due to positive feedback. d. The feedback mechanism would maintain relatively constant levels of thyroxin throughout tissue targets.

Which of the following steps in a signaling pathway typically occurs first once a chemical messenger reaches a target cell? a. Specific genes are activated. b. A second messenger molecule is produced. c. A ligand binds to a receptor. d. Specific proteins are synthesized.

A lack of insulin production by the pancreas leads to various symptoms such as excess urination, thirst, lack of energy and fatigue. The direct cause of a lack of energy and fatigue is that There are inadequate glucose levels in the blood The body cells do not absorb glucose from the blood The kidneys excrete too much of glucose The body cells burn glucose supplies too rapidly

TGC GTG CTT AAG CGG TGT GCA CGT TGC mRNA: ACG CAC GAA UUC GCC ACA CGU GCA ACG Amino acid: THR HIS GLU PHE AIA THR ARG AIA THR What kind of mutation is this? Do you think it will affect the protein's function? Why?

Botulism can cause muscle weakness, paralysis and the inability to breath. This is due to the action of botulinum toxin, which cleaves SNARES in affected cells. What process in affected cells is blocked by the destruction of SNARES? The initial tethering of neurotransmitter-filled secretory vesicles at the membrane. Fusion of secretory vesicles to the plasma membrane and neurotransmitter release. Endocytosis of neurotransmitters for reuse. Transport of neurotransmitter-filled secretory vesicles towards the membrane.

A 10 year old male is about 15cm taller than his peers and has enlarged hands and feet. Lab results show GH: 38.4 ng/mL (normal range, 0-5 ng/mL); insulin- like growth factor 1 (IGF-1), 624.0 ng/mL (normal range for age, 220-616 ng/mL) (T3/T4/TSH/Cortisol/Prolactin were within normal limits). Which of the following is a likely condition? Grave's disease Hyperthyroidism Gigantism Acromegaly

Let's say you are a protein hormone x. Choose your receptor and transduction pathways and response

What would a side-effect of removing organ L be? Choose all that apply The individual would not be able to regulate their calcium ion blood levels The individual would have the same symptoms as a person with untreated Type I diabetes mellitus The individual would need to take synthetic ADH The individual would not be able to regulate their blood glucose levels

Consider the following physiological reactions: an increase in plasma glucose and a reduction in immune function. Which of the following hormone imbalances is likely? Increase in insulin Increase in TSH Increase in cortisol Increase in glucagon

What is one major benefit of the endocrine system? The bloodstream can carry hormones to various body locations, even if they are not close to the gland that made them. Hormones are very fast acting, and can effect change almost immediately There is no benefit to the endocrine system. It sucks. The endocrine system can store their hormones in ducts, to be released at a later time

You are a scientist studying a cell surface receptor. This receptor is expressed on the cells you are culturing in the lab, and when you add a hormone that binds to the cells, there is a cell response. However, when you add double the amount of hormone, the cell response remains the same. Why? The cell surface receptors are downregulated The cell surface receptors are saturated The hormone changed specificity to the receptor There is negative feedback on the receptor

The outermost region of the adrenal gland is responsible for ... Water and electrolyte balance Carbohydrate metabolism Blood pressure Steroid hormone secretion

Lesioning (damaging) the PVN in the hypothalamus has the effect of ... eeding behavior. The PVN would normally function to ... the .... Stimulating; inhibit; lateral nucleus Inhibiting; inhibit; arcuate nucleus Inhibiting; excite; lateral nucleus Stimulating; inhibit; arcuate nucleus

What is most likely to happen if an individual restricts consumption of dietary fat to very low levels? A development of scurvy B. development of atherosclerosis. C. loss of insulation around vital organs D. loss of hemoglobin from red blood cells

All of the following are examples of nonspecific immunity EXCEPT O mucus O acidic pH O HCI in stomach O memory B cells O complement response

What hormone causes Graves disease when levels are too high and Cretinism in children when levels are too low? GH TSH ACTH FSH LH

If the body has lost blood what hormone should be released? EPO FSH LH Prolactin Leptin

What physiologic responses would serve to decrease blood pressure? Increase in heart rate Secretion of natriuretic peptides ADH release by the posterior pituitary All of the above