SOAL SOAL SISTEM HORMON SMA

1) Gluconeogenesis occurs in the liver due to the action of ________.

A) aldosterone

B) insulin

C) secretin

D) cortisol

Answer: D

2) Normal development of the immune response is due in part to hormones produced by the

________.

A) adrenal medulla

B) pancreas

C) thyroid gland

D) thymus gland

Answer: D

3) Virtually all of the protein or amino acid-based hormones exert their effects through

intracellular ________.

A) ions

B) deactivators

C) nucleotides

D) second messengers

Answer: D

4) Which of the following is not a category of endocrine gland stimulus?

A) enzyme

B) humoral

C) neural

D) hormonal

Answer: A

5) Chemical substances secreted by cells into the extracellular fluids that regulate the metabolic

function of other cells in the body are called ________.

A) enzymes

B) antibodies

C) proteins

D) hormones

Answer: D

6) The hypothalamic-hypophyseal tract ________.

A) connects the hypophysis to the pituitary gland

B) is partly contained within the infundibulum

C) conducts aldosterone to the hypophysis

D) is the site of prolactin synthesis

Answer: B

7) Tropic hormones ________.

A) include ACTH and TSH

B) do not regulate the function of other endocrine glands

C) exert their effects on cells by direct gene activation

D) include GH and PRL

Answer: A

8) Growth hormone ________.

A) is also called somatostatin

B) is regulated by humoral mechanisms

C) secretion results in a decrease in muscle mass

D) promotes long bone growth during the formative years

Answer: D

9) Oxytocin ________.

A) release is an example of a positive feedback control mechanism

B) is an adenohypophyseal secretion

C) exerts its most important effects during menstruation

D) controls milk production

Answer: A

10) ADH ________.

A) increases urine production

B) promotes dehydration

C) is produced in the adenohypophysis

D) is inhibited by alcohol

Answer: D

11) Thyroid hormone exerts its influence by ________.

A) entering some cells and binding to intracellular receptors within the nuclei

B) exerting only a minor effect on body metabolism

C) causing a reduction in the number of blood vessel adrenergic receptors, and therefore

decreasing blood pressure

D) acting to decrease basal metabolic rate

Answer: A

12. Gonadocorticoid(s) ________.

A) synthesized by the adrenal medulla are primarily androgens

B) production by the adrenal gland is insignificant compared with sex hormone release

from the gonads during late puberty

C) secretion inhibition is highly dependent on a negative feedback loop involving ACTH

D) hypersecretion can result in adrenogenital syndrome, also called feminization

Answer: B

13) Sometimes prolonged excessive exposure to high hormone concentrations causes a

phenomenon known as ________.

A) diabetes mellitus

B) cellular inhibition

C) down-regulation

D) metabolism of protein kinases

Answer: C

14) Which of the following is not a change that may be caused by hormonal stimulus?

A) a change in membrane potential

B) the stimulation of a genetic event resulting in protein synthesis

C) an increase in enzymatic activity

D) direct control of the nervous system

Answer: D

15) The ability of a specific tissue or organ to respond to the presence of a hormone is dependent

on ________.

A) the location of the tissue or organ with respect to the circulatory path

B) the membrane potential of the cells of the target organ

C) the presence of the appropriate receptors on the cells of the target tissue or organ

D) nothingall hormones of the human body are able to stimulate any and all cell types

because hormones are powerful and nonspecific

Answer: C

16) Several hormones are synthesized in the hypothalamus and transported to the anterior

pituitary gland. The mechanism of transportation from hypothalamus to anterior pituitary

gland is through the ________.

A) hepatic portal system

B) general circulatory system

C) hypophyseal portal system

D) feedback loop

Answer: C

17) The neurohypophysis or posterior lobe of the pituitary gland is not a true endocrine gland

because ________.

A) it is strictly a part of the neural system and has little or nothing to do with hormonal

release

B) embryonically it was an endocrine tissue, but in the adult human it is no longer

functional

C) it is unable to function as an endocrine tissue because it is actually part of the neural

system due to its location

D) it is only a hormone storage area that receives hormones from the hypothalamus for

release

Answer: D

18) Insulin, a small (51-amino-acid) protein, is synthesized by the beta cells of the pancreas. This

hormone is released ________.

A) in excessive amounts in obese people

B) in response to severe physical stress (i.e., a ten-mile run)

C) when the bodyʹs glucose level rises

D) when the bodyʹs glucose level drops

Answer: C

19) Steroid hormones exert their action by ________.

A) entering the nucleus of a cell and initiating or altering the expression of a gene

B) finding an appropriate cell receptor and initiating cAMP activity

C) stimulating the synthesis of a glycogen

D) increasing blood pressure

Answer: A

20) The second-messenger mechanism of hormone action operates by ________.

A) synthesizing more of the hormone than is actually needed

B) increasing the basal metabolic rate in the target organ

C) not responding to a feedback mechanism

D) binding to specific receptors and employing the services of G proteins and cAMP

Answer: D

21) Hormones often cause a cell to elicit multiple responses; this is because ________.

A) there are thousands of receptors on the cell membrane

B) the receptors bind to several hormones at the same time

C) the protein kinases are rapidly metabolized

D) during protein kinase activation, enzymes phosphorylate many other enzymes

Answer: D

22) Cells that respond to peptide hormones usually do so through a sequence of biochemical

reactions involving receptor and kinase activation. In order for cells to respond, it is necessary

for first and second messengers to communicate. This is possible because ________.

A) peptide hormones always enter the cell membrane and elicit a response without

assistance from other messengers

B) hormones alter cellular operations through stimulation of a gene directly

C) G protein acts as the link between first and second messengers

D) the hormone receptor complex moves into the cytoplasm as a unit

Answer: C

23) Thyroid hormone (a small iodinated amine) enters target cells in a manner similar to ________.

A) insulin, because insulin is a small peptide

B) steroid hormones, because both diffuse easily into target cells

C) growth hormone, because the thyroid works synergistically with thyroid hormone

D) glucagon, because the structure of glucagon is similar to that of thyroid hormone

Answer: B

24) When it becomes necessary to enlist the fight-or-flight response, a hormone that is released

during the alarm phase of the general adaptation syndrome is ________.

A) estrogen

B) epinephrine

C) angiotensinogen

D) renin

Answer: B

25) One of the least complicated of the endocrine control systems directly responds to changing

blood levels of ions and nutrients. Which of the following describes this mechanism?

A) the rapid oxidation of carbohydrates

B) catabolic inhibition

C) protein synthesis

D) humoral stimulation

Answer: D

26) The major targets of growth hormone are ________.

A) the blood vessels

B) the adrenal glands

C) the liver

D) bones and skeletal muscles

Answer: D

27) The parathyroid glands maintain adequate levels of blood calcium. This is accomplished

through ________.

A) blocking the action of growth hormone

B) targeting the bone and activating osteoclasts so that calcium will be released

C) antagonizing the synthesis of calcitonin

D) slowing the activity of tissues that require calcium for activity

Answer: B

28) Which organ is responsible for synthesizing ANP?

A) the heart

B) the kidney

C) the skin

D) the spleen

Answer: A

29) Mineralocorticoid is to aldosterone as glucocorticoid is to ________.

A) testosterone

B) estrogen

C) cortisol

D) epinephrine

Answer: C

30) Leptin is secreted by ________.

A) lymphocytes

B) adipocytes

C) goblet cells

D) fibroblasts

Answer: B

31) The most important regulator of electrolyte concentrations in extracellular fluids is ________.

A) insulin

B) aldosterone

C) glucagon

D) cortisol

Answer: B

32) Which of the following is not a steroid-based hormone?

A) estrogen

B) aldosterone

C) epinephrine

D) cortisone

Answer: C

33) Which of the following does not act as a second messenger in second-messenger systems of

hormone action?

A) cyclic AMP

B) calmodulin

C) cyclic GMP

D) inositol triphosphate

Answer: B

34) Select the correct statement about the structure or function of chemical messengers.

A) Prostaglandins are biologically active peptides.

B) Modified cholesterol forms the main structural component of the peptone hormones.

C) An amino acid derivative can be a hormone.

D) An example of a paracrine is testosterone.

Answer: C

35) Which of the following would be associated with the action of steroids on cells?

A) extracellular receptors with a specificity for only a single amino acid sequence on the

hormone

B) an enzyme that catalyzes the formation of cyclic AMP

C) second-messenger systems

D) a hormone-receptor complex that interacts directly with the cellʹs DNA

Answer: D

36) Cellular responses to hormones that initiate second-messenger systems include ________.

A) possible activation of several different second-messenger systems

B) cyclic AMP phosphodiesterase formation of an active second messenger

C) formation of a specific protein kinase that acts on a series of extracellular intermediates

D) hormone binding to intracellular receptors

Answer: A

37) Regulating hormones from the hypothalamus ________.

A) enter venous circulation and travel to the heart, which pumps the hormone-containing

blood to the pituitary

B) enter the hepatic portal system, which feeds the pituitary

C) travel by arteries to the pituitary

D) first enter into the hypophyseal portal system

Answer: D

38) ACTH ________.

A) is secreted by the posterior pituitary

B) secretion is regulated by a hypothalamic secretion

C) causes the release of hormones from the adrenal medulla

D) is not a tropic hormone

Answer: B

39) Which of the following is true about calcium homeostasis?

A) Increased calcitonin levels will cause increased blood calcium levels.

B) High calcium levels cause bone resorption.

C) Parathyroid hormone causes an increase in osteoblast activity.

D) Parathyroid hormone is the single most important regulator of calcium levels in the

blood.

Answer: D

40) Aldosterone ________.

A) is secreted by the neurohypophysis

B) functions to increase sodium reabsorption

C) presence increases potassium concentration in the blood

D) production is greatly influenced by ACTH

Answer: B

41) The only amine hormone to act like a steroid is ________.

A) TH

B) ACTH C) GH

D) ADH

Answer: A

42) Which organ does not have hormone production?

A) heart

B) kidney

C) liver

D) skin

Answer: C

43) In circumstances where the body requires prolonged or increased levels of a hormone, the

DNA of target cells will specify the synthesis of more receptors on the surface of the cells of the

target organ. This is known as ________.

A) the cellʹs sensitivity reaction

B) cellular affinity

C) up-regulation

D) a reaction to a stressor

Answer: C

44) Eicosanoids do not include ________.

A) paracrines

B) leukotrienes

C) hydrocortisones

D) prostaglandins

Answer: C

45) A man has been told that he is not synthesizing enough follicle-stimulating hormone (FSH),

and for this reason he may be unable to father a child. Choose the correct statement to explain

this problem.

A) FSH stimulates estrogen secretion by ovarian cells; therefore it is not synthesized by

males.

B) The physician is wronga hormone made in the adenohypophysis could not influence

fertility.

C) FSH stimulates sperm production in the testes.

D) The man must be producing progesterone, which inhibits the synthesis of FSH.

Answer: C

46) Which of the following organs is affected by thyroid hormone in adults?

A) liver

B) spleen

C) thyroid gland

D) brain

Answer: A

47) Thyroxine is a peptide hormone, but its mechanism is different from other peptide hormones.

Which of the following statements is true concerning this difference?

A) It causes positive feedback.

B) It does not require a second messenger to effect a response.

C) It is very specific in the cell type it targets.

D) It is a stimulant of cellular metabolism and targets all cells.

Answer: B

48) Factors that inhibit TSH release do not include ________.

A) growth hormone-inhibiting hormone (GHIH)

B) rising levels of glucocorticoids

C) somatostatin

D) excessively high blood iodine concentrations

Answer: D

49) Glucocorticoids enable the body to deal appropriately with stress. They accomplish this by

_______.

A) increasing blood glucose, fatty acid, and amino acid levels and enhancing blood pressure

B) decreasing the heart rate, thus decreasing blood pressure

C) stimulating the pancreas to release insulin

D) blocking the neurotransmitters that prepare the body for the stress response

Answer: A

50) What ion is sometimes used as a second messenger of amino acid-base hormones?

A) Iron

B) Calcium

C) Sodium

D) Chlorine

Answer: B


DETAIL

HORMON

• Hormon adalah senyawa organic yang dihasilkan oleh kelenjar endokrin (kelenjar buntu)
• Menurut bahasa hormone berasal dari kata “hormaen” yang berarti menggiatkan
• Hormon juga disebut sebagai sistem yang tersusun dari penghasil hormon (kelenjar/glandula) dan hormon itu sendiri. Hormon itu bentuknya cair yang dihasilkan oleh kelenjar.

MACAM KELENJAR

• kelenjar secara umum ada 2 macam, yaitu kelenjar eksokrin dan kelenjar endokrin.
• kelenjar eksokrin adalah kelenjar yang menghasilkan hormon yang dikeluarkan tidak di darah, tetapi di permukaan suatu organ atau jaringan epitel.
• kelenjar endokrin adalah kelenjar yang mengeluarkan hormon ke darah.

CIRI HORMON

• Hormon akan dikeluarkan oleh kelenjar endokrin bila ada rangsangan (stimulus).
• Hormon tidak mempunyai saluran khusus
• Hormon masuk kedalam system peredaran darah menuju ke organ sasaran.
• Jumlah hormone yang diperlukan sedikit, tapi mempunyai kemampuan kerja yang besar dan lama
• jika jumlah hormon yang disekresikan berlebih atau kurang, akan timbul kelainan-kelainan pada tubuh.
• Beberapa hormon juga bekerja secara antagonis, contohnya insulin dengan glukogen, serta PTH dengan kalsitonin

FUNGSI HORMON

• Mengendalikan proses pertumbuhan dan perkembangan
• Mengendalikan proses reproduksi
• Mengendalikan proses metabolisme zat
• Menjaga keseimbangan dalam tubuh atau disebut juga homeostasis.
• Mengatur tingkah laku (behavioral)

HUBUNGAN SYARAF DENGAN HORMON

• Hormon dan sistem saraf bersama-sama mengatur regulasi tubuh:
• Mengatur kesetimbangan cairan tubuh dalam proses homeostatis (nutrisi, metabolisme, kesetimbangan garam dan air, kesetimbangan gula hingga ekskresi)
• Bereaksi terhadap rangsang dari luar tubuh
• Berperan dalam pertumbuhan dan perkembangan
• Pengaturan dan penyimpanan energi

KELENJAR BUNTU BERDASARKAN AKTIVITAS

• Kelenjar yang bekerja sepanjang hayat, misal hormon yang  memegang peranan dalam metabolisme.
• Kelenjar yang bekerja mulai masa tertentu, misal hormon kelamin.
• Kelenjar yang bekerja sampai masa tertentu saja, misal hormon pertumbuhan, hormon timus.

KELENJAR BUNTU BERDASARKAN LETAK

• Kelenjar hipofisis, terletak di dasar otak besar.
• Kelenjar tiroid atau kelenjar gondok, terletak di daerah leher.
• Kelenjar paratiroid atau kelenjar anak gondok, terletak di dekat kelenjar gondok.
• Kelenjar epifise.
• Kelenjar timus atau kelenjar kacangan.
• Kelenjar adrenal atau suprarenalis, terletak di atas ginjal.
• Kelenjar pankreas atau pulau-pulau Langerhans, terletak di sebelah bawah lambung (ventrikulus).
• Kelenjar usus dan lambung.
• Kelenjar kelamin atau kelenjar gonad, pada wanita terletak di daerah rongga perut, pada pria di dalam buah zakar dalam kantong skrotum.

KELENJAR HIPOFISIS

• Terletak di bagian dasar otak di bawah hipotalamus
• Terdiri dari 3 bagian:hipofisis depan (lobus anterior), Hipofisis bagian tengah (lobus intermediet), hipofisis bagian belakang (lobus posterior) 

Hypofise depan ( Anterior) 

Hipofisis depan (lobus anterior) menghasilkan hormone:

1. Somatotropin (STH=Growth Hormon)

• Fungsi: merangsang sintesis protein, metabolism lemak, dan otot
• Defisiensi: dwarfisme (kerdil)
• Kelebihan: gigantisme (tumbuh raksasa pada anak), akromegali (pertumuhan tidak seimbang pada persendian dan ujung tulang orang dewasa)

2. Tirotropin ( TSH = Thyroid stimulsting hormone)

• Fungsi: mengontrol pertumbuhan dan perkembangan kelenjar gondok, merangsang tiroid mensekresikan tiroksin.

3. Adrenokortikotropik (ACTH=Adrenocorticotropic hormone)

• Fungsi: merangsang korteks adrenal untuk mensekresikan glukokortikoid dan mineralokortikoid.

4. Prolactin (LTH= luteotropic hormone)

• Fungsi: merangsang kelenjar mamae(kelenjar susu) dan memelihara korpus luteum dalam memproduksi progesterone

5. Gonadotropin

Terdiri dari:

A. FSH (Folice stimulating hormone)

• pada wanita: mengatur perkembangan ovarium dan berpengaruh pada kematangan folikel
• pada pria: mengatur pembentukan sperma (spermatogenesis)

B. LH (Luteinizing Hormone)

• Pada wanita: merangsang pelepasan telur dari ovarium (ovulasi) dan meluruhkan dinding ovarium
• Pada pria: disebut ISCH (interestitial cell stimulating hormone) untuk merangsang sel intersisial testis memproduksi  testosterone dan androgen (androsteron)

Hipofisis bagian tengah (lobus intermediet)

• penghasil melanotropin (MSH= melanocyt stimulating hormone)
• untuk hewan berfungsi sintesis melanin dan penyebaran melanofor  untuk kamuflase.

Hipofisis bagian belakang (lobus posterior) mensekresikan hormone:

• Vasopresin (ADH=anti diuretic hormone) yang berfungsi pada reabrorbsi tubulus ginjal. Defisiensi: sering buang air & diabetes insipidus
• Oksitosin, berfungsi  merangsang kontraksi otot dinding Rahim dan sekresi air susu.

KELENJAR TIROID

• Terdapat pada leher bagian depan, dibawah jakun
• Menghasilkan hormone tiroksin dan Hormon Kalsitonin 

Hormon Tiroksin

• Hormon tiroksin akan aktif jika mendapat perintah dari TSH yang berada   di hipofisis. Kerja hormon tiroksin banyak dipengaruhi oleh kadar iodin di dalam darah dan mengontrol kecepatan metabolisme tubuh untuk menghasilkan energy
• Kelebihan: morbus basedowi (meningkatnya metabolisme, meningkatnya denyut jantung, gugup, emosional, pelupuk mata terbuka lebar, dan bola mata melotot (eksoftalmus), pada anak akan menyebabkan gigantisme
• Kekurangan: kretinisme, mixoedem (obesitas & kecerdasan menurun pada orang dewasa)

Hormone kalsitonin

• Hormon Kalsitonin berperan mengatur keseimbangan kadar kalsium di dalam darah sehingga mencegah kalsium keluar dari tulang.

KELENJAR PARATIROID

• Terdapat pada dorsal kelenjar tiroid
• Menghasilkan parathormon (PTH). Parathormon merupakan hormon yang bersama dengan kalsitonin mengatur kadar kalsium tubuh.
• Defisiensi: peningkatan ekstibilitas system saraf dengan kerja otot, tetanus
• Kelebihan: kadar kalsium dalam darah meningkat, hal ini akan mengakibatkan terjadinya endapan kapur pada ginjal, disebut batu ginjal.

KELENJAR THIMUS

• terletak dalam rongga dada dan melekat di belakang tulang dada.
• Membuat hormon somatotropin yang berguna untuk pertumbuhan.
• Defisiensi: -usia muda:kretinisme (kerdil)
• Kelebihan: -usia muda: gigantisme
• usia dewasa: akromegali (pertumbuhan ujung tulang pipa ke arah samping)

KELENJAR SUPRARENALIS

• Terletak diatas ginjal
• Tersusun dari korteks dan medulla

BAGIAN KORTEX

• Mineralokortikoid: mengatur keseimbangan air dan elektrolit Na dan K
• Gonadokortikoid: androgen dan estradiol dalam jumlah sedikit
• Glukokortikoid: metabolism lemak & protein untuk membentuk glukosa

Bagian medulla:

• Adrenalin: menyempitkan pembuluh darah sehingga meningkatkan tekanan darah, mengendurkan otot bronkiolus sehingga melegakan pernapasan. metabolism karbohidrat dengan sekresi glukosa dari hati

Kelainan pada adrenal

1. adison: hipofungsi adrenal
2. coushing syndrome: hiperfungsi adrenalin
3. virilisme: munculnya ciri kelamin sekunder pada pria dan wanita

• Noradrenalin: menaikan tekanan darah dengan merangsang serabut otot dalam dinding pembuluh darah untuk kontraksi

KELENJAR EPIFISIS (PINEAL)

• Melekat pada otak diatas cerebellum
• Menghasilkan hormone melatonin

Fungsi melatonin:

• Penghambat fungsi reproduksi
• Zat antioksidan dalam otak
• Mengatur ritme bilogis harian

KELENJAR PANKREAS (LANGERHANS)

• Kelenjar pankreas merupakan kelenjar endokrin yang menghasilkan hormon, sekaligus merupakan kelenjar eksokrin karena menghasilkan enzim pencernaan.
• Menghasilkan Insulin, berfungsi antagonis dengan hormon adrenalin, yaitu untuk mengubah gula menjadi glikogen di dalam hati dan otot.
• Mengatur kadar gula darah agar tetap seimbang
• Defisiensi: diabetes mellitus

KELENJAR KELAMIN (GONADE)

• Kelenjar kelamin pria (testis) : menghasilkan androgen (testosterone).
• ICSH (Intersistiel Cell Stimulating Hormone), salah satu hormon yang dihasilkan kelenjar pituitari berperan dalam pendewasaan tersebut. 
• ICSH merangsang testis (buah zakar) untuk menggetahkan androgen atau testosterone.
• Fungsi testosterone: spermatogenesis, memberi feedback pada sekresi Luteinizing Hormon

 Kelenjar kelamin wanita (ovarium)

• Masa pubertas dipicu oleh hormon yang dihasilkan kelenjar pituitari, yaitu FSH (Follicle Stimulating Hormone) dan LH (Luteinizing Hormone).
• menghasilkan hormon estrogen dan progresteron

Estrogen

• dihasilkan folikel de graaf.

Fungsi

• bertanggung jawab dalam memelihara fungsi organ kelamin 
• merangsang perkembangan endometrium 
• memacu pertumbuhan ciri-ciri kelamin sekunder wanita,
• menghentikan FSH yang disekresi Hipofise anterior 
• Merangsang keluarnya LH dari Hipofise anterior 

Progesterone

• Dihasilkan korpus luteum . Badan Kuning

Fungsi:

• Menghalangi produksi FSH
• Mengatur pertumbuhan plasenta
• Memperlancar produksi ASI bersama laktogen

KELENJAR GASTROINTESTINAL

Meliputi Kelenjar pada usus dan kelenjar dilambung

Kelenjar di usus

• Menghasilkan sekretin & kolesistokinin yang berfungsi merangsang pengeluaran getah pancreas

Kelenjar di lambung

• Menghasilkan gastrin yang berfungsi merangsang pengeluaran getah lambung

KELENJAR HIPOTALAMUS

Menghasilkan hormone:

• CRF (Corticitropin  Releasing Factor)
• GnRF (gonadotropin releasing factor)
• TRF (tirotropin releasing factor)

Ketiganya langsung disekresikan ke  hipofisis

KELENJAR PLASENTA

• Menghasilkan hormone progesterone & HCG (human chorionic gonadotropin) yang fungsinya sama dengan LH & FSH