thyroid + parathyroid glands

Question 1

describe the thyroid gland

Answer 1

• located in the neck just below the larynx
• two lobes
• follicle cells secrete hormones in response to thyroid-stimulating hormone

Question 2

what are the two hormones secreted by the thyroid gland?

Answer 2

• thyroxine

- calcitonin

Question 3

describe thyroxine

Answer 3

• stimulates metabolism/ releases glucose
• made up of four iodide ions
• affect all cells in the body

Question 4

what effect does thyroxine have on peripheral tissues?

Answer 4

• elevate oxygen consumption + energy consumption rate
• increase heart rate and force of contraction = rise in blood pressure
• increase sensitivity to sympathetic stimulation
• maintain normal sensitivity of respiratory centers to changes in oxygen and carbon dioxide concentration
• stimulate the formation of red blood cells and thereby enhance oxygen delivery
• stimulate the activity of other endocrine tissues

Question 5

what is hyperthyroidism?

Answer 5

= excessive production of thyroxine

• metabolic rate climbs + skin flushed
• blood pressure + heart rate increase
• the individual is restless and excitable
• limited energy reserves and fatigues easily

Question 6

what is an example of hyperthyroidism?

Answer 6

graves disease

- excess thyroid activity leads to groite + protrusion of eyes

Question 7

how can hyperthyroidism be treated?

Answer 7

• drugs that block thyroid glands
• a drink containing radioactive iodine
• surgery to remove some or all of the gland

Question 8

what are the 5 symptoms of hyperthyroidism and their reasons?

Answer 8

• rapid heart rate = increased need for nutrients, oxygen to be delivered to cells, and waste removal
• weight loss = increased metabolism > all energy in food consumed is used in cellular respiration
• increased appetite = increased metabolism = hunger centre (hypothalamus) stimulated
• restless + fatigue = increased metabolism > all glucose is converted to ATP + lack backup energy reserves therefore fatigue easily

Question 9

what is hypothyroidism?

Answer 9

= inadequate production of thyroxine or dietary iodide

Question 10

what is hypothyroidism in children?

Answer 10

cretinism

• inadequate skeletal and nervous development
• inadequate metabolic rate with 40% below normal levels
• retarded growth + puberty

Question 11

what are the treatments for hypothyroidism?

Answer 11

• tablets containing thyroid hormone

- iodine in the diet

Question 12

what are the 5 symptoms of hypothyroidism and their reasons?

Answer 12

• slow heart rate = less glucose + oxygen required by cells
• unexplained weight gain = decreased metabolism > less glucose in blood is being utilised by cells for cellular respiration + glucose in blood is converted to fat for storage
• fatigue = lower metabolic rate > less ATP is produced from cellular respiration
• intolerance to cold = less heat is being produced from cellular respiration resulting in lower body temp
• thyroid glands swell in an attempt to make more thyroxine

Question 13

describe calcitonin

Answer 13

= reduce calcium levels in the blood

• released by c cells
• protien
• targets bones + kidneys

Question 14

describe the parathyroid gland

Answer 14

• located at the surface of the lobes of the thyroid gland
• 4
• pea-sized

Question 15

what does the parathyroid gland secrete

Answer 15

• parathyroid hormone

Question 16

describe the parathyroid hormone

Answer 16

= increases calcium levels in the blood + phophate excretion in the urine

• protein
• targets bones + kidney