Deck 28: Hormonal Control in Animals

Question 1

Hormonal control systems of widely differing degrees of complexity are found in representatives of

A) animals.
B) fungi.
C) protists.
D) parasites.
E) All of the answers are correct.

Answer 1

All of the answers are correct.

Question 2

Which of the following statements about hormones is NOT true? Hormones

A) allow responses to changes in the environment.
B) act at low concentration.
C) initiate cellular activities.
D) are secreted in response to specific stimuli.
E) are classified with respect to the distances over which they act.

Answer 2

initiate cellular activities.

Question 3

Secretions of the pancreas into the duodenum are regarded as

A) autocrine secretions.
B) endocrine secretions.
C) exocrine secretions.
D) paracrine secretions.
E) both endocrine and autocrine.

Answer 3

exocrine secretions.

Question 4

Paracrine hormones are usually secreted into the

A) blood.
B) interstitial matrix.
C) digestive system.
D) lymph.
E) duodenum.

Question 5

Pheromones are secretions that are

A) endocrine.
B) exocrine.
C) paracrine.
D) autocrine.
E) None of the answers are correct.

Question 6

Which statement best describes the way in which a hormonal system functions?

A) Hormonal systems are generally used to communicate very rapidly over long distances to provide very transient responses.
B) Hormonal systems operate independently of nervous systems in facilitating responsiveness to the environment.
C) Hormonal systems operate in an integrated fashion with nervous systems and are generally used to produce sustained responses to sustained changes in the environment.
D) Hormone systems control growth and reproduction while the nervous system controls homeostasis.
E) Hormonal systems only operate on the basis of negative feedback loops involving suites of hormones.

Question 7

Peptide hormones act by

A) binding to water-soluble receptors in the cytoplasm.
B) interacting with DNA to promote transcription.
C) binding to surface receptors, and frequently interact with a G-linked protein to produce a second messenger within the cell.
D) producing sustained metabolic effects rather than rapid enzyme cascades.
E) binding to nuclear receptors to initiate gene transcription.

Question 8

Endocrine hormone secreting cells are derived mostly from tissues in the

A) digestive and excretory systems.
B) excretory and immune systems.
C) digestive and respiratory systems.
D) respiratory and immune systems.
E) excretory systems and immune systems.

Question 9

Hormonal systems of invertebrates

A) are solely neurosecretory systems in which neurosecretory cells may be aggregated into neurohaemal organs.
B) are generally not well known, although an extensive literature exists for the molluscs.
C) can include separate endocrine organs as well as neurosecretory systems in higher invertebrates.
D) operate on the basis of peptide hormones only.
E) only control growth and development.

Question 10

Ecdysone

A) is important in regulating moulting in insects.
B) mobilises stored fuel reserves, such as fat and glycogen, at the onset of flight.
C) precipitates diapause.
D) is synthesised only in the prothoracic gland of insects.
E) induces social behaviour in the Hymenoptera.

Question 11

At which stage during hemimetabolous development does ecdysone reach its peak concentration?

A) 1^st instar
B) 3^rd instar
C) 4^th instar
D) Subadult
E) Adult

Question 12

Diapause in insects is

A) a period of dormancy.
B) a period of dispersal.
C) controlled by gonadotrophins.
D) the emergence of the adult form.
E) time between larval stages.

Question 13

The family of hormones produced by the corpora cardiaca, that mobilise fat at the onset of flight, are the

A) adipokinetic hormones.
B) ecdysis-triggering hormones.
C) eclosion hormones.
D) prothoracicotropic hormones.
E) crustacean cardiactive peptide.

Question 14

In vertebrates, the major neurosecretory region is found at the base of the brain and is called the

A) hypophysis.
B) hypothalamus.
C) adenohypophysis.
D) neurohypophysis.
E) pituitary gland.

Question 15

In mammals, the posterior pituitary gland or pars nervosa secretes two important hormones called

A) vasopressin and prolactin.
B) ADH and melanophore-stimulating hormone.
C) vasopressin and oxytocin.
D) prolactin and adrenocorticotrophic hormone.
E) anti-diuretic hormone and prolactin.

Question 16

Which of the following statements about hormones in vertebrates is true? The hormones oxytocin and vasopressin

A) are anterior pituitary hormones.
B) regulate metabolism of lipids.
C) regulate K⁺ and Na⁺ levels in the kidney.
D) are fat-soluble steroid hormones.
E) are both nona-peptides.

Question 17

Which statement most accurately describes the function of the hypothalamo-hypophyseal portal system? The hypothalamo-hypophyseal portal system

A) carries releasing/inhibiting hormones from the hypothalamus to the neurohypophysis.
B) vascularises the hypothalamus and the hypophysis.
C) carries neurosecretions from the median eminence into the general circulatory system and then the adenohypophysis.
D) carries neurosecretions from the median eminence directly to the anterior pituitary gland.
E) is an array of capillaries which supply the hormone secreting cells of the posterior pituitary.

Question 18

In some reptiles, what becomes a functioning eye?

A) Pineal gland
B) Parapineal gland
C) Adrenohypophysis
D) Olfactory nerve
E) Anterior pituitary gland

Question 19

Which of the following statements is NOT true? In mammals, the adrenal gland

A) secretes mainly protein-based hormones.
B) is located at the anterior end of the kidneys.
C) secretes glucocorticoids which influence protein metabolism..
D) is essential for the maintenance of body sodium levels.
E) secretes mineralocorticosteroids in response to angiotensin II.

Question 20

The thyroid gland is stimulated by

A) thyroxine to release triiodothyronine.
B) thyrotrophic hormone to release thyroxine.
C) thyrotrophin-releasing hormone to release thyrotrophic hormone.
D) thyrotrophin-releasing hormone to release thyroxine.
E) TSH to release corticotropin-releasing hormone.

Question 21

In humans, a condition known as thyrotoxicosis

A) causes accumulation of water in subcutaneous fat.
B) is caused by lack of iodine.
C) lowers metabolic rate.
D) is a result of excessive thyroid hormone activity.
E) lowers heart rate and decreases blood pressure.

Question 22

The adrenal cortex

A) secretes mineralocorticoids such as aldosterone, which mediates kidney function in response to the release of angiotensin.
B) is stimulated to release glucocorticoids, such as cortisol, by corticotrophin-releasing hormone.
C) secretes ADH primarily in response to adrenocorticotrophic hormone.
D) secretes angiotensin II in response to low blood Na⁺ levels.
E) secretes adrenocorticotrophic hormone in response to the release of corticotrophin-releasing hormone.

Question 23

In animals, gonadotrophic hormones

A) stimulate the gonads to produce gametes.
B) inhibit sexual maturation.
C) stimulate spawning.
D) are produced by the ovaries and testes.
E) are released from the hypothalamo-hypophyseal portal-system.

Question 24

Which of the following statements about mammalian reproductive systems is NOT true?

A) Follicle stimulating hormone stimulates the secretion of oestrogen.
B) The corpus luteum secretes progesterone.
C) Follicle stimulating hormone is only present in females.
D) Luteinising hormone levels peak at ovulation.
E) Testosterone is converted to oestradiol in brain cells of most vertebrates.

Question 25

In male mammals, luteinising hormone (LH)

A) stimulates spermatogenesis.
B) secretion is inhibited by inhibin.
C) stimulates formation of the corpus luteum.
D) stimulates absorption of amino acids and protein.
E) stimulates the secretion of androgens.

Question 26

In humans, the islets of Langerhans

A) secrete insulin.
B) secrete glucagon.
C) secrete somatostatin.
D) are embedded in the pancreas.
E) All of the answers are correct.

Question 27

Glucagon

A) has hyperglycaemic effects.
B) is secreted by the acini of the pancreas when blood glucose levels fall.
C) is secreted by beta cells of the islets of Langerhans.
D) induces gluconeogenesis.
E) works with insulin to reduce blood glucose.

Question 28

Secretin

A) is stimulated by the alkalinity of secretions from the pancreas.
B) regulates secretion from the islets of Langerhans in the pancreas.
C) operates as an antagonist of gastrin.
D) is secreted by S cells in the duodenum in response to a fall in pH and is controlled by a negative feedback mechanism.
E) is secreted into the intestine to stimulate digestion.

Question 29

Polypeptide growth factors

A) act as mitogens.
B) are secreted by a wide variety of cells.
C) are a group of polypeptide hormones.
D) bind to membrane bound receptors to activate an intracellular signal cascade.
E) All of the answers are true.

Question 30

Which of the following mammalian cells do NOT contain the eicosanoid, arachidonic acid?

A) Smooth muscle cells
B) Bone cells
C) Erythrocytes
D) Platelets
E) Lymphocytes.

Question 31

In teleost fish, neural control of the anterior pituitary is

A) endocrine as in all vertebrates.
B) under paracrine control by the hypothalamus.
C) inhibited by the release of specific anterior pituitary hormones.
D) under developed and does not function in hormonal control.
E) under the control of the median eminence.

Question 32

Animal hormones are

A) secreted in response to specific stimuli.
B) transported via the blood to their site of action.
C) essential for growth, reproduction and maturation.
D) regulated by negative feedback control mechanisms.
E) All of the answers are correct.

Question 33

The main link between the endocrine system and the nervous system is the

A) anterior pituitary gland.
B) posterior pituitary gland.
C) hypothalamus.
D) pancreas.
E) brain.

Question 34

The endocrine cells of the thyroid gland

A) are arranged in follicles of cuboidal cells with a large lumen when stimulated.
B) produce hormones such as thyroxine and TSH.
C) produce the thyroid peptide hormone thyroxine (T4) which contains iodine.
D) produce a protein precursor, thyroglobulin, which is stored in the lumen of the follicle.
E) All of the answers are correct.

Question 35

Several diseases in humans are related to the malfunction of thyroid hormones, including

A) thyrotoxicosis which results in slow metabolism and dilated pupils.
B) goitre, or enlarged thyroid, caused by increased thyroid secretions.
C) myxoedema, an abnormal water accumulation in tissues, due to increased thyroid hormones.
D) cretinism, due to impaired growth and development which results from low iodine intake.
E) All of the answers are correct.

Question 36

Which of the following statements is CORRECT?

A) Oestrogens and androgens are peptide hormones which are usually converted to more active species in the blood.
B) In males, FSH stimulates the secretion of steroidal androgens.
C) In mammals, FSH stimulates ovarian follicles to proliferate and form the corpus luteum.
D) In oviparous monotremes, the corpus luteum produces progesterone which prepares the reporductive tract to receive the embryo and maintain the pregnancy.
E) Oestrogens and androgens influence the development of gametes and ovulation.

Question 37

Endocrine glands

A) are organs with non-differentiated cells.
B) secrete hormones onto a body cavity or surface.
C) include organs such as the salivary glands.
D) secrete hormones through a duct.
E) All the options listed are incorrect.

Question 38

Which of the following is NOT a hormone

A) Gangliocrine hormone
B) Pheromone
C) Prostaglandin
D) Paracrine hormone
E) Autocrine hormone

Question 39

A person consuming a diet devoid of unsaturated fatty acids would be deficient in which class of hormones?

A) Pheromones
B) Autocrine hormones
C) Paracrine hormones
D) Prostaglandins
E) Gangliocrine hormones

Question 40

How would a hydrophilic hormone NOT regulate target gene transcription?

A) Via signal transduction
B) By binding to a specific hormone receptor on the plasma membrane
C) By initiating phosphorylation of target proteins inside the cell
D) By crossing the plasma membrane and binding to a hormone response element in the nucleus
E) By stimulating production of a secondary messenger such as cAMP

Question 41

If a pancreas were to release bicarbonate, this could be in response to

A) low levels or absence of secretin.
B) low pH in the duodenum.
C) high levels of oestrogens.
D) a positive feedback loop regulatory framework.
E) high pH in the pacreas.

Question 42

Where do hypothalamic neurosecretions accumulate before being transported to the anterior pituitary gland?

A) The posterior pituitary gland
B) At the apex of the hypothalamus
C) The median eminence
D) The ulterior ligamous
E) In the duodenum

Question 43

A person with dwarfism is found to have normal levels of circulating Growth Hormone (GH) and has fully functioning kidneys capable of producing sufficient levels of insulin-like growth factors (IGF-I, IGF-II). What is one reason why this person could still be a dwarf?

A) Prolactin deficiency
B) Non-functional GH binding receptors on the kidneys
C) Excess levels of IGF-I
D) Excess levels of IGF-II
E) Overactive hypothalamus

Question 44

What are the target cells of melatonin, and which hormone decreases their activity?

A) Hypothalamus, the activity of which is decreased by IGF-II.
B) Thymus, the activity of which is decreased by luteinising hormone.
C) The pineal gland, the activity of which is decreased by parathyroid hormone.
D) Suprachiasmatic nucleus, the activity of which is decreased by melatonin.
E) Adenohypophysis, the activity of which is decreased by progesterone.

Question 45

Production of gluconeogenic hormones is stimulated by

A) release of an inhibitor from glucagon binding receptors.
B) insulin synthesis.
C) an increase in glucose oxidation.
D) a decrease in glycogen breakdown.
E) a fall in blood glucose levels.