Endocrine System

Question 1

The endocrine system has what 4 functions:

Answer 1

• maintains homeostasis
• controls storage and utilisation of energy
• regulates growth, developments and reproduction
• responds to environmental stimuli

Question 2

What are the four principle mechanisms of communication between cells

Answer 2

• gap junctions
• parachute (local) hormones
• hormones
• neurotransmitters

Question 3

What are gap junctions

Answer 3

• Pores in cell membrane allow signalling molecules, nutrients and electrolytes to move from cell to cell

Question 4

Paracrine (local) hormones are

Answer 4

• secreted into tissue fluids to affect nearby cells

Question 5

Hormones are…

Answer 5

• chemical messengers that travel in the bloodstream to other tissues and organs

Question 6

Neurotransmitters are…

Answer 6

• released from neurons to travel across synaptic cleft to second cell

Question 7

What are the components of the Endocrine system

Answer 7

• Endocrine system: glands, tissues and cells
• endocrinology: study of the system and diagnosis and treatment of disorders
• endocrine glands: organs that are sources of hormones
• hormones: chemical messengers transported by the blood to stimulate physiological responses in cells of tissues and organs

Question 8

What are Receptor Proteins

Answer 8

• 3 dimensional shape that fits a specific signal molecule
• signal molecule and receptor proteins bind, a change in the receptor protein is induced and a response in the cell is generated

Question 9

What are the 2 chemical classes of hormones

Answer 9

• lipid soluble: passes through cell membrane and bind to receptors in the cytoplasm of cells
• water soluble: cannot pass through cell membrane. Instead binds to receptors on the surface of membranes

Question 10

Anterior Pituitary Hormones

Answer 10

• follicle stimulating hormone (FSH)
• lutenising hormone (LH)
• thyroid stimulating hormone (TSH)
• adrenocorticotropic hormone (ACTH)
• growth hormone (GH)

Question 11

Posterior pituitary hormones consist of:

Answer 11

(Produced by the Hypothalamus)
• Antidiuretic Hormone (ADH)
• Oxytocin (OT)

Question 12

Function of the adrenal medulla

Answer 12

• when stimulated, releases catechilamines (adrenaline and noradrenaline) and a trace of dopamine directly into the bloodstream
• increases alertness and prepares body for physical activity

Question 13

Functions of catecholamines

Answer 13

• mobilize high energy fuels, lactate, fatty acids and glucose
• glycogenolysis and gluconeogensis boost glucose levels
• glucose-sparing effect because inhibits insulin secretion
• muscles use fatty acids saving glucose for brain
• increases blood pressure, heart rate, blood flow to muscles, pulmonary air flow and metabolic rate
• decreases digestion and urine production

Question 14

The adrenal cortex produces:

Answer 14

• 25 steroid hormones called corticosteroids and corticoids

Question 15

Adrenal cortex secretes 5 major steroid hormones from what 3 layers of glandular tissues?

Answer 15

• Zona glomerulosa (thin, outer layer)
• zona fasciculata (thick, middle layer)
• zona reticularis (narrow, inner layer)

Question 16

Catergories of Corticosteroids:

Answer 16

• mineralocorticoids
• glucocorticoids
• sex steroids

Question 17

Addisons disease is:

Answer 17

• primary adrenal insufficiency or hypoadrenalism, a rare disorder of the adrenal glands

Question 18

Causes of addisons disease:

Answer 18

• primary adrenal insufficiency: adrenals: autoimmune disease, genetics, surgical removal, infections, cancer
• secondary: pituitary: cancer, autoimmune disease, genetics and surgical removal
• tertiary: hypothalamus: sudden removal of corticosteroids (prescription or treatment of Cushing disease)

Question 19

Signs and symptoms of Addison’s crisis:

Answer 19

• abdominal pain
• nausea
• diarrhoea
• fatigue
• dizziness (postural hypotension)
• pigmentation: buccal, scars, palmar creases, generalised
• Hypoglycaemia
•hypotension
•Hyperkalaemia

Question 20

Where is the thyroid gland located

Answer 20

Just below the larynx

Question 21

Function of thyroid hormones

Answer 21

• stimulate protein synthesis and growth
• promote maturation of the nervous system
• increase cell respiration rate
• increases digestion
• increases body temperature

Question 22

Symptoms of Goitre (disease of the thyroid)

Answer 22

• tight feeling in the throat
• coughing
• hoarseness in voice
• dysphasia
• difficulty in breathing

Question 23

Causes of giotre

Answer 23

1. Iodine deficiency
2. Graves’ disease - hyperthyroidism
3. Hashimoto’s disease
4. Thyroid cancer
5. Thyroiditis

Question 24

What is hyperparathyroidism

Answer 24

Glands makes too much PTH and can result in hypercalcemia, usually caused by a benign tumor.

Question 25

Parathyroid disease can cause:

Answer 25

• osteoporosis • kidney stones • heart disease • high blood pressure

Question 26

Symptoms of parathyroid disease

Answer 26

• muscle weakness • fatigue • increased need for sleep • aches and pains in joints and bones

Question 27

Functions of melatonin include

Answer 27

• regulation of sleep-wake cycle • regulation of immune response • menstrual cycle regulation • regulation of energy metabolism and glucose homeostasis

Question 28

What does the pineal gland secrete

Answer 28

Hormone melatonin

Question 29

Symptoms of hyperthyroidism

Answer 29

• increased metabolic rate • weight loss • muscular weakness and nervousness • eyes may protrude (due to edema in orbits)

Question 30

Pituitary disorders

Answer 30

• gigantism • acromegaly <^caused by hypersecretion of GH • dwarfism < hyposecretion of GH • diabetes insipidus • hypothesis • prolactinoma

Question 31

What hormone does the pineal gland produce

Answer 31

Melatonin

Question 32

Role of melatonin

Answer 32

Regulation of sleep cycle Regulation of immune response Regulation of menstrual cycle Regulation of metabolism

Question 33

What is a goitre

Answer 33

Abnormal enlargement of the thyroid gland