Endocrine System

Which of the following hormones contributes to the regulation of the body's fluid and electrolyte balance?

ADH

A small molecule binds to a G protein, preventing its activation. What direct effect will this have on signaling that involves cAMP?

Adenylyl cyclase will not be activated.

Describe the mechanism of hormone response resulting from the binding of a hormone with an intracellular receptor.

An intracellular hormone receptor is located within the cell. A hydrophobic hormone diffuses through the cell membrane and binds to the intracellular hormone receptor, which may be in the cytosol or in the cell nucleus. This hormone-receptor complex binds to a segment of DNA. This initiates the transcription of a target gene, the end result of which is protein assembly and the hormonal response.

Compare and contrast the role of estrogens and progesterone.

Both estrogens and progesterone are steroid hormones produced by the ovaries that help regulate the menstrual cycle. Estrogens play an important role in the development of the female reproductive tract and secondary sex characteristics. They also help maintain pregnancy. Progesterone prepares the body for pregnancy and helps maintain pregnancy.

Describe the role of placental secretion of relaxin in preparation for childbirth.

Relaxin produced by the placenta is thought to soften and widen the pubic symphysis. This increases the size of the pelvic outlet, the birth canal through which the fetus passes during vaginal childbirth.

Describe several main differences in the communication methods used by the endocrine system and the nervous system.

The endocrine system uses chemical signals called hormones to convey information from one part of the body to a distant part of the body. Hormones are released from the endocrine cell into the extracellular environment, but then travel in the bloodstream to target tissues. This communication and response can take seconds to days. In contrast, neurons transmit electrical signals along their axons. At the axon terminal, the electrical signal prompts the release of a chemical signal called a neurotransmitter that carries the message across the synaptic cleft to elicit a response in the neighboring cell. This method of communication is nearly instantaneous, of very brief duration, and is highly specific.

Cushing's disease is a disorder caused by ________.

abnormally high levels of cortisol

The walls of the atria produce which hormone?

atrial natriuretic peptide

Athletes may take synthetic EPO to boost their ________.

blood oxygen levels

Endocrine glands secrete

chemical messengers that travel in the bloodstream

What secretory cell type is found in the adrenal medulla?

chromaffin cells

In the elderly, decreased thyroid function causes ________.

decreased metabolic rate

Hormones produced by the thymus play a role in the ________.

development of T cells

Do endocrine glands have ducts or are they ductless?

ductless

The end result of the RAAS is to ________.

increase blood pressure

The production of FSH by the anterior pituitary is reduced by which hormone?

inhibin

The gonads produce what class of hormones?

steroid hormones

A newly developed pesticide has been observed to bind to an intracellular hormone receptor. If ingested, residue from this pesticide could disrupt levels of ________.

thyroid hormone

Which of the following is an anterior pituitary hormone? ADH oxytocin TSH cortisol

tsh

How many hormones are produced by the posterior pituitary?

0

If innervation to the adrenal medulla were disrupted, what would be the physiological outcome?

Damage to the innervation of the adrenal medulla would prevent the adrenal glands from responding to the hypothalamus during the fight-or-flight response. Therefore, the response would be reduced.

Distinguish between the effects of menopause and andropause on fertility

Menopause occurs as the result of a progressive decline in the function of the ovaries, resulting in low estrogen and progesterone levels. Ovulation ceases, and postmenopausal woman can no longer conceive a child. In contrast, andropause is a much more gradual and subtle decline in testosterone levels and functioning. A man typically maintains fertility until very old age, although the quantity, quality, and motility of the sperm he produces may be reduced.

What are the three regions of the adrenal cortex and what hormones do they produce?

The outer region is the zona glomerulosa, which produces mineralocorticoids such as aldosterone; the next region is the zona fasciculata, which produces glucocorticoids such as cortisol; the inner region is the zona reticularis, which produces androgens.

Summarize the role of GI tract hormones following a meal.

The presence of food in the GI tract stimulates the release of hormones that aid in digestion. For example, gastrin is secreted in response to stomach distention and causes the release of hydrochloric acid in the stomach. Secretin is secreted when acidic chyme enters the small intestine, and stimulates the release of pancreatic bicarbonate. In the presence of fat and protein in the duodenum, CCK stimulates the release of pancreatic digestive enzymes and bile from the gallbladder. Other GI tract hormones aid in glucose metabolism and other functions.

Compare and contrast the short-term and long-term stress response.

The short-term stress response involves the hormones epinephrine and norepinephrine, which work to increase the oxygen supply to organs important for extreme muscular action such as the brain, lungs, and muscles. In the long-term stress response, the hormone cortisol is involved in catabolism of glycogen stores, proteins, and triglycerides, glucose and ketone synthesis, and downregulation of the immune system.

Compare and contrast the thymus gland in infancy and adulthood.

The thymus gland is important for the development and maturation of T cells. During infancy and early childhood, the thymus gland is large and very active, as the immune system is still developing. During adulthood, the thymus gland atrophies because the immune system is already developed.

The adrenal glands are attached superiorly to which organ?

kidney

Name the target tissues for prolactin.

mammary glands

The hypothalamus is functionally and anatomically connected to the posterior pituitary lobe by a bridge of ________.

nerve axons

A student is in a car accident, and although not hurt, immediately experiences pupil dilation, increased heart rate, and rapid breathing. What type of endocrine system stimulus did the student receive?

neural

The function of the placental hormone human placental lactogen (hPL) is to

prepare the breasts for lactation

Which of the following responses s not part of the fight-or-flight response? pupil dilation increased oxygen supply to the lungs suppressed digestion reduced mental activity

reduced mental activity