Tag: endocrine system in humans

Questions Related to endocrine system in humans

Choose the correct answer from the alternatives given.
Which of the following hormone initiates secretion of milk?

biology chemical coordination and integration hormones coordination in human beings- chemical control endocrine system in humans

  1. Prolactin

  2. Luteinizing hormone

  3. Somatotrophic hormone

  4. Progesterone

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Correct Option: A
Explanation:

(A) Prolactin regulates the growth of the mammary glands and formation of milk in them. 

(B) Leutinizing hormone stimulates gonadal activity and hence are called gonadotropin.
(C) Somatotrophic hormone or Growth hormone is a peptide hormone that stimulates growth, cell reproduction etc.
(D) Progesterone supports a pregnancy. It also acts on the mammary glands.
So the correct answer is prolactin.

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Which of the following hormones is incorrectly paired with its action?

biology chemical coordination and integration hormones coordination in human beings- chemical control endocrine system in humans

  1. Oxytocinstimulates uterine contraction in childbirth

  2. Thyroxinestimulates metabolic processes

  3. Insulinstimulates glycogen breakdown in liver

  4. ACTHstimulates release of glucocorticoids by adrenal cortex

Show answer
Correct Option: C
Explanation:

(A) Oxytocin initiates vigorous uterine contractions in females at the time of the childbirth, milk secretion by mammary glands, contraction of smooth muscles.

(B) Thyroxine is primarily responsible for regulation of metabolism.
(C) Insulin stimulates conversion of glucose to glycogen (glycogenesis).
(D) ACTH stimulates the synthesis and secretion of steroid hormones called glucocorticoids. 
So the correct answer is insulin stimulates glycogen breakdown in liver.

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One of the chief differences between pheromones and local hormones is:

biology chemical coordination and integration hormones coordination in human beings- chemical control endocrine system in humans

  1. the distance over which they act

  2. that one is a chemical messenger and the other is not

  3. that one is made by invertebrates and the other is made by vertebrates

  4. all of the above

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Correct Option: A
Explanation:

Local hormones - A number of hormones are secreted by the cells but not in glands and widely dispersed in the body are called local hormones. Example are histamine, prostaglandins, etc.

Pheromones are chemicals used for communication amongst the organism of the same species. 
So the correct answer is the distance over which they act. 

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Which hormone stimulates secretion of milk in mammary glands?

biology chemical coordination and integration hormones coordination in human beings- chemical control endocrine system in humans

  1. TSH

  2. Prolactin

  3. Vasopressin

  4. Thyroxine

Show answer
Correct Option: B
Explanation:

(A) Thyroid stimulating hormone (TSH) promotes growth and function if thyroid gland. 

(B) Prolactin hormone stimulates lactation (milk production) and has a direct effect on the breasts immediately after parturition.
(C) Vasopressin or antidiuretic hormone (ADH) acts mainly at the kidney and stimulates resorption of water and electrolytes by the distal tubules and thereby reduce the loss of water through urine (diuresis). 
(D) Thyroxine is primarily responsible for regulation of metabolism.
So the correct answer is vasopressin.

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Which of the following is not an accurate statement about hormones?

biology chemical coordination and integration hormones coordination in human beings- chemical control endocrine system in humans

  1. Hormones are chemical messengers that travel to target cells through the circulatory system

  2. Hormones often regulate .homeostasis through antagonistic functions

  3. Hormones of the same chemical class usually have the same general function

  4. Hormones are often regulated through feedback loops

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Correct Option: C
Explanation:

Hormones are nonnutrient chemicals which act as intercellular messengers and are produced in trace amounts. All hormones produce their specific effects on target tissue/cells by binding to the specific proteins called as hormone receptors. The normal functioning of endocrine glands and the level of hormones in the body needs to be regulated. This is possible through a feedback mechanism.

So the correct answer is hormones of the same chemical class usually have the same general function.

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Second messengers include:

biology chemical coordination and integration hormones coordination in human beings- chemical control endocrine system in humans

  1. steroid hormones

  2. cyclic AMP

  3. protein hormones

  4. both (a) and (b)

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Correct Option: B
Explanation:

Hormones which interact with membrane-bound receptors normally do not enter the target cell but generate second messengers (eg, cyclic AMP, IP3, Calcium Ions etc) which in turn regulate cellular metabolism. Hormones which interact with intracellular receptors (eg, steroid hormones, iodothyronines, etc) mostly regulate gene expressions or chromosome function by the interaction of hormone receptor complex with the genome. 

So the correct answer is cyclic AMP.

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Which organ does not synthesize hormones?

biology chemical coordination and integration hormones coordination in human beings- chemical control endocrine system in humans

  1. Heart

  2. Adrenal cortex

  3. Anterior pituitary

  4. Pineal gland

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Correct Option: A
Explanation:

Endocrine gland lack ducts and are called ductless glands. Their secretions are called hormones. Adrenal cortex secrets many hormones commonly called as corticoids. Anterior pituitary secretes many hormones such as GH, PRL, TSH, ACTH etc. The pineal gland secretes three hormones namely, melatonin, serotonin, adrenoglomerulotropin.

So the correct answer is the heart. 

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Human sex hormones are classified as:

biology chemical coordination and integration hormones coordination in human beings- chemical control endocrine system in humans

  1. amino acids

  2. lipids

  3. triacyiglycerols

  4. proteins

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Correct Option: B
Explanation:

Human sex hormone is steroid hormones. The natural steroid hormones are generally synthesized from cholesterol in the gonads and adrenal glands. These forms of hormones are lipids. 

So the correct answer is lipids.

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Which of the following hormones is called an antidiuretic hormone?

biology chemical coordination and integration hormones coordination in human beings- chemical control endocrine system in humans

  1. Glucagon

  2. Prolactin

  3. Vasopressin

  4. Cortisone

Show answer
Correct Option: C
Explanation:

(A) Glucagon acts mainly on the liver cells and stimulates glycogenolysis resulting in increased blood sugar (hyperglycemia).

(B) Prolactin regulates the growth of the mammary glands and formation of milk in them. 
(C) Vasopressin or antidiuretic hormone (ADH) acts mainly at the kidney and stimulates resorption of water and electrolytes by the distal tubules and thereby reduce the loss of water through urine (diuresis). 
(D) Cortisone is the main glucocorticoid.
So the correct answer is vasopressin.

Which of the following statements is correct in relation to the endocrine system?

biology chemical coordination and integration hormones coordination in human beings- chemical control endocrine system in humans

  1. Non-nutrient chemicals produced by the body in trace amount that act as intercellular messenger are known as hormones

  2. Releasing and inhibitory hormones are produced by the pituitary gland

  3. Adenohypophysis is under direct neural regulation of the hypothalamus

  4. Organs in the body like gastrointestinal tract, heart, kidney and liver to not produce any hormone

Show answer
Correct Option: A
Explanation:

The endocrine system consists of organ, tissue and cells that produce a small amount of non-nutrient chemicals which sends signals to other cells or acts as an intercellular messenger. These chemicals are known as hormones which are transported to their target site through blood.

So the correct answer is 'Non-Nutrient chemicals produced by the body in trace amount that acts as intercellular messenger are known as hormones'.