Human Physiology Final

The endocrine system communicates with target cells by way of

chemical messengers secreted into the blood stream.

Hormones are chemical messengers that enter the blood which carries them from their site of secretion to the cells where they act.

Members of which group of hormones are made from cholesterol?

steroid.

All steroid hormones are derived from cholesterol.

T or F? In general, steroid hormones bind to receptors on cell membranes, whereas peptide hormones bind to receptors inside of cells.

False.

In general, peptide hormones bind to receptors on cell membranes, whereas steroid hormones bind to receptors inside of cells.

T or F? The hypophyseal portal system (circulation) refers to the blood vessels that link the anterior pituitary with the target glands of the anterior pituitary hormones.

False.

The hypophyseal portal system (circulation) refers to the blood vessels linking the hypothalamus with the anterior pituitary.

Which statement is true?

Only peptide hormones bind to plasma proteins.

Steroid hormones do not bind to plasma proteins.

Hydrophobic hormones like steroid and thyroid hormones need binding proteins because they are not very soluble in the blood plasma.

Hydrophobic hormones like petide and protein hormones need binding proteins because they are not very soluble in the blood plasma.

-Hydrophobic hormones like steroid and thyroid hormones need binding proteins because they are not very soluble in the blood plasma. Hydrophobic hormones like steroid and thyroid hormones need binding proteins because they are not very soluble in the blood plasma.

Which are hormones secreted by the posterior pituitary?

antidiuretic hormone (ADH) and oxytocin. The hormones secreted by the posterior pituitary are antidiuretic hormone (ADH) and oxytocin.

Hypothalamic releasing hormone with the hormone it causes to be released from the anterior pituitary. CRH

ACTH

Hypothalamic releasing hormone with the hormone it causes to be released from the anterior pituitary. TRH

TSH

Hypothalamic releasing hormone with the hormone it causes to be released from the anterior pituitary. GnRH

LH and FSH

Hypothalamic releasing hormone with the hormone it causes to be released from the anterior pituitary. GHRH

GH

Which is an example of long-loop negative feedback?

inhibition of corticotropin-releasing hormone (CRH) by cortisol. Short loop negative feedback is when the anterior pituitary hormone has a negative feedback effect on the hypothalamus. Long-loop negative feedback is when the gland hormone has a negative feedback effect on the hypothalamus (and anterior pituitary).

T or F? A reduction in thyroid hormone secretion would tend to cause an increase in metabolic rate.

False

What term describes hormones that influence the secretion of other hormones?

Tropic. Tropic hormones influence the secretion of other hormones.

T to F? During the fed state, there is net synthesis of fat, glycogen, and protein, but this process is reversed during the fasted state.

True

Which of the following acts to decrease blood glucose levels?

insulin.

Which of the following hormones is released in response to real or perceived physiological stress?

cortisol

Hyperglycemia, skinny arms and legs with extra fat in the face (moon face) and trunk (abdominal striae / stretch marks) are symptoms of

Cushing's Syndrome

Weight loss, rapid heart rate, and heat sensitivity are likely symptoms of

Hyperthyroidism

Which of the following statements about thyroid hormones is TRUE?

At the level of the target cell, T4 is converted into T3 by deiodinase enzymes.

T or F? Iodine is needed for the production of triiodothyronine (T3) and thyroxine (T4) by the thyroid gland.

True

T or F? Increased levels of cortisol in the blood will feed back to reduce Corticotropin Releasing Hormone via long-loop negative feedback.

True

Which hormone does Growth hormone cause to be released from the liver

Insulin like growth factor

T or F? Thyroid hormones increase metabolic rate, at least in part, by inhibiting the activity of the Na+/K+ ATPase.

False

T or F? The kidneys produce urine of a constant composition at all times, in order to maintain homeostasis of extracellular fluid.

False

Given these parts of a nephron:

1. renal corpuscle

2. collecting duct

3. loop of Henle

4. distal tubule

5. proximal tubule.

Arrange the parts in order as fluid flows from the filtration membrane through the nephron.

Beginning at the filtration membrane, the sequence of parts of a nephron through which fluid flows is: 1,5,3,4,2.

Which of the following structures composes the renal corpuscle?

Glomerular capillaries and Bowman's capsule

The renal corpuscle is composed of the glomerular capillaries which are surrounded by Bowman's capsule. The afferent arteriole supplies blood to the glomerular capillaries, but it is not contained within the corpuscle.

There are three basic renal processes for urine formation. Which of the following is NOT one of these processes?

Excretion

Urine formation begins with the filtration of plasma from the glomerular capillaries into Bowman's space. This process is termed glomerular filtration. During its passage through the tubules, the filtrate's composition is altered by movements of substances from the tubules to the peritubular capillaries, and vice versa. When the direction of movement is from tubular lumen to peritubular capillary plasma, the process is called tubular reabsorption. Movement in the opposite direction—that is, from peritubular plasma to tubular lumen—is called tubular secretion.

Which of the following is least likely to be filtered into Bowman's capsule in a normal, healthy person?

protein

Many solutes (electrolytes, glucose, amino acids, fatty acids, vitamins, urea, uric acid and creatinine) pass through the filtration membrane, but blood cells and proteins do not.

All of the following substances are present in proximal tubular fluid in the kidney, but which one is NOT normally present in urine because it is completely reabsorbed?

glucose

The body completely reabsorbs useful organic molecules like glucose

T or F? If a substance is partially filtered at the glomerulus and is completely secreted it will not be present in the urine.

False

T or F? Constriction of the afferent arterioles increases hydrostatic pressure in the glomerular capillaries and thus increases glomerular filtration rate.

False

Constriction of the afferent arterioles decreases hydrostatic pressure in the glomerular capillaries and thus decreases glomerular filtration rate.

T or F? ADH is secreted by the posterior pituitary and stimulates the insertion of aquaporins in the cell membranes of the collecting duct which allows for the production of a concentrated urine.

True

Angiotensinogen is converted to Angiotensin I by______________, which is then converted into____________ by _________________ and ultimately causes a(n)__________________ in blood pressure.

renin, angiotenisn II, ACE, increase

When food is consumed the site where digestion begins is the

Mouth

Digestion begins in the mouth. Both chewing, which breaks food particles down into smaller particles, and the salivary enzyme amylase, which begins the chemical digestion of starch, contribute to the process of digestion. Digestion continues in the stomach, but most chemical digestion actually takes place in the small intestines.

The muscular contractions that move material through the digestive tract are called

peristalsis

Swallowing or deglutition moves food from the oral cavity to the esophagus. Mass movements occur in the large intestine to move fecal material into the rectum. Segmentation contractions are mixing contractions, which occur in the small intestine. Peristalsis creates waves of contractions through most of the digestive tract to move the material along.

One of the major functions of bile salts is

to emulsify fat to smaller particles (fatty droplets).

The liver produces and secretes about 600-1000 mL of bile each day. Bile contains water, bilirubin, cholesterol, fats, fat-soluble hormones, lecithin, bicarbonate ions, and bile salts. Many of the components of bile are waste products, but bile does play two roles in digestion. Bile helps neutralize the acid chyme (via bicarbonate ions) coming from the stomach. Bile salts emulsify fats to fatty droplets, which increases the surface area for the digestive enzyme lipase. Lipase can now very efficiently and quickly breakdown the fatty droplets to fatty acids and glycerol.

T or F? The lumen of the gastrointestinal tract is continuous with the external environment.

True.

It opens at the mouth and exits at the anus. This is the "tube within a tube" structure you should have been taught in general bio.

T or F? The food bolus entering into the stomach from the esophagus helps to stimulate the gastric phase of digestion.

True

In the stomach, parietal cells secrete

hydrochloric acid

T or F? Polysaccharides must be broken down to disaccharides in order to be absorbed

False

A zymogen

is the inactive form of an enzyme

T or F? The products of lipid digestion/emulsification in the small intestine are absorbed into the capillaries at the intestinal villi.

False

T r F? Voluntary control of defecation is associated with relaxation of the internal sphincter.

False.

The external sphincter is made of skeletal muscle, whereas the internal sphincter is composed of smooth muscle and cannot be voluntarily controlled.