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Iodine deficiency promotes the formation of enlarged thyroid glands (goitre) because a) more thyroid hormones are now produced in the thyroid gland. b) the thyroid gland switches to production of a different hormone. c) reduced levels of thyroid hormones fail to prevent stimulation of thyroid gland by TRH and TSH. d) iodine now needs to be synthesized in the thyroid gland.

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Sixta Kovacek
Sixta KovacekLv2
9 Jun 2019
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Related questions

Key: A.Increase

B.Decrease

C. Remain thesame

For questions 19-20 use the following information Thyroid-stimulating hormone (TSH) is secreted from the anterior pituitarygland and acts on the thyroid gland to increase the secretion ofthyroid hormones. Thyroid hormones, on the other hand, have anegative-feedback effect on TSH secretion (See Fig. 16.8 in yourtext). For a person having normal thyroid function, the rate atwhich TSH and thyroid hormones are secreted remains within a normalrange of concentrations. In some people, however, the immune systembegins to produce an abnormal substance that functions likeTSH.

Predict what that substance will do to:

19. _____the rate of thyroid stimulating hormone secretion

20. _____ the rate of thyroid hormone secretion.

For question 21 use the following information. Background:Hormones are dissolved in blood plasma and transported either in afree form or bound to plasma proteins. Hormones that are lipidsoluble, such as steroids and thyroid hormone, circulate in theblood in combination with these plasma proteins. Hormones that bindto plasma proteins do so in a reversible fashion according to theequation:

H + BP <-----------> HBP

(Hormone) (BindingProtein) (Hormone bound to binding protein)

An equilibrium is established between the free plasma proteinsand the hormones bound to the plasma proteins. This equilibrium isimportant because only a free hormone is able to diffuse throughcapillary walls and bind to target cells. The combination of ahormone bound to a binding protein reduces the rate at which theydiffuse through the walls of capillaries.

This increases the half-life of the hormone. The half-life isthe length of time it takes to eliminate half a dose of a substancefrom the circulatory system. The half-life of a hormone is astandard measurement used by endocrinologists because it allowsthem to predict the rate at which a given hormone will beeliminated from the body.

21. _____How is the half-life of a hormone affected by adecrease in the concentration of the

specific plasma protein to whichthat hormone binds? Remember if the time to

eliminate a hormone from theblood stream is longer then the half life has increased.

If the time to eliminate ahormone shortens then the half life has decreased

22. _____Consider a hormone that is secreted in large amounts ata given interval, modified

chemically by the liver, andexcreted by the kidney at a rapid rate, making the

half-life of the hormone in thecirculatory system very short. The hormone therefore

rapidly increases in the bloodand then decreases rapidly. Predict the

consequences of liver and kidneydisease on the blood levels of that hormone.

For question 23 use the following background information:Periodic increases in the sensitivity of some tissues to certainhormones is called up-regulation. It results from an increase inthe rate of receptor molecule synthesis. In many tissues the numberof hormone receptors rapidly decreases after exposure to certainhormones. This is called down-regulation.

Problem. Estrogen is a hormone secreted by theovary. It is secreted in greater amounts after menstruation and afew days before ovulation. Among its many effects is causing

up-regulation of receptors in the uterus for another hormonesecreted by the ovary called progesterone. Progesterone is secretedafter ovulation. A major effect of progesterone is to cause theuterus to become ready for the embryo to attach to its wallfollowing ovulation. Pregnancy cannot occur unless the embryoattaches to the wall of the uterus.

23. ______Predict the consequences on becoming pregnant if theovary secretes too little

estrogen?

24. ______ Predict the effect of inadequate dietary intake ofcalcium on PTH secretion

25. ______ Predict the effect of inadequate dietary intake ofcalcium on Calcitriol secretion

1. Kidneys help to maintain a proper balance of _________ within the body.

Phosphorous

Chloride

Potassium

Calcium Phosphate

ions

All of the above

2. The nervous system has how many major categories?

3

2

13

4

3. Which major category of the nervous system contains both the Somatic and the Autonomic divisions?

Central Nervous System

Peripheral Nervous System

Neither of these

Both of these

4. Which organ or structure helps to control the master endocrine gland (pituitary gland)?

The pancreas

The thorax

Peyer’s patches

The hypothalamus

6. This tiny gland is located at the base of the brain and produces the hormone melanin.

Parathyroid

Pituitary

Hypothalamus

Pineal

7. These glands are situated right above the kidneys. The hormones produced by these glands help us to cope with stress.

Thyroid

Parathyroid

Hypothalamus

Adrenals

8. The hormones necessary for the production of sperm are produced in the __________.

Kidneys

Testes

Ovaries

None of the above

9. The bloodstream assists the endocrine organs and structures by:

Removing hormones from the body

Delivering hormones to target cells

Delivering hormones to secretory cells

The bloodstream does not come into contact with endocrine structures or organs
10. The pancreas _____________.

Is a master gland that controls many other glands

Produces progesterone and oestrogen

Is a salivary gland

Regulates blood sugar, aid in digestion

11. The basic function of the endocrine system is ________ in nature.

Digestive

Reproductive

Hormonal

Proximal

13. Urinary tract infections (UTIs) are experienced by many people during their lifetimes. Urinary tract infections can involve any bacterial infection of the urinary system structures; the kidneys, bladder, ureters, or urethra. They are caused by bacteria entering the body through the urethra and traveling upward into the body. Symptoms can range from mild discomfort when urinating to extreme pain and the loss of blood during urination. They occur more frequently in women than men, and are often treated by antibiotics in addition to home remedies, such as drinking more water and drinking cranberry juice.

Based on what you have learned about the cause of urinary tract infections, which of the following precautions would help to prevent reoccurring infections?

Taking pain medication when symptoms occur

Placing a hot pack on the abdomen when symptoms occur

Practicing good hygiene Exercising regularly

14. The nervous system is divided into two major divisions: the Central Nervous System and the Peripheral Nervous System. Those divisions have structures that can be classified as belonging to two different subdivisions: the Somatic and the Autonomic systems. The nervous system can be summarized as a complex system of interconnected nerves and special cells called neurons that are used to transmit information (by means of small electrical impulses). Use the information in the table below to help answer questions about the nervous system. Division Organs & Structures Functions Central Nervous System (CNS) Brain Spinal Cord Nerves This is the body’s assessment and communication center. It analyzes the information received from the sensory neurons and responds. Peripheral Nervous System (PNS) Sensory Neurons Ganglia (clusters of neurons) Nerves that connect to one another and to the CNS The sensory neurons react to physical stimuli such as light, sound, heat, and pressure, and transmit that information to the CNS. Subdivisions Description Examples Somatic The Somatic system is comprised of nerves that connect the brain and spinal cord to the muscles of the body and sensory receptors in the skin. Reactions to physical stimuli like heat or light. Using your hand to touch Eating food Autonomic The Autonomic system largely involuntary. This system controls the unconscious functions of the body. Breathing Blood Pressure

Feeling overwhelmed or startled by exposure to very loud noises is likely a reaction to information collected by which subdivision of the nervous system:

Somatic

Autonomic

No answer text provided.

No answer text provided.

15. The thyroid gland is perhaps the most well-known member of the pancreatic system. Many adults are screened for thyroid problems during routine physical exams. This butterfly shaped gland is found at the base of the neck and releases hormones that affect the body’s metabolism (the way the body uses energy). The thyroid’s two main hormones are T3 and T4, and they affect many body functions, including: • Breathing • Heart rate • Central and peripheral nervous systems • Body weight • Muscle strength • Menstrual cycles • Body temperature • Cholesterol levels Two common disorders associated with the thyroid include hyperthyroidism and hypothyroidism. Some of the symptoms associated with these disorders are listed in the table below. Hyperthyroidism (Too many hormones released) Hypothyroidism (Too few hormones released) Anxiety Irritability or moodiness Nervousness, hyperactivity Sweating or sensitivity to high temperatures Hand trembling (shaking) Hair loss Missed or light menstrual periods Trouble sleeping Tiredness and fatigue Difficulty concentrating Dry skin and hair Depression Sensitivity to cold temperature Frequent, heavy periods Joint and muscle pain A patient complains of arthritis-like pain in the joints of her hands, but tests for arthritis come back negative. The doctor then suggests a thyroid function test. The doctor is most likely concerned about:

High levels of T3 and T4 hormones in the body

Low levels of T3 and T4 hormones in the body

No answer text provided.

No answer text provided

59. Saltatory Conduction

a. occurs in unmyelinated nerve fiber

b. is slower than conduction by local current flow because the myelin acts as an insulator to show the impulse down

c. involves the impulse jumping from one node of ranvier ro adjacent node

d. refers to the action potential spreading from one schwann cell to the adjacent schwann cell.

e. more than one of the above is correct

63. the universal energy currency in cells is

a. RNA b. ATP c. Glucose d. Glucogen e. DNA

66. which of the classes of hormones triggers the synthesis of new intracellular proteins within the target cell (via stimulation of DNA transcription and translation)?

a. peptides b. catecholamines c. steroids d. thyroid hormone e. both c and d are correct

68. hormones,

a. are all similar chemical composition

b. combine with specific receptors on the target cell's surface or inside the target cell

c. are secreted at a constatnt rate

d. all act by activating adenyl cyclase, which transforms ATP into cAMP

e. all of the above are correct

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