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 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 Addisons disease:

Answer 19

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