The Endrocrine System Flashcards

Question

What are steroid hormones

Answer 1

Steroid hormones are lipid-soluble • Secreted by, e.g. adrenal cortex, ovaries and testes Steroid hormones are transported through the blood by specialised carrier proteins • They are mostly derived from cholesterol

Answer 2

Corticosteroids Sex steroids

Answer 3

Cortisol Aldosterone

Answer 4

Protein/polypeptide hormones are water-soluble • Secreted by, e.g. pituitary, pancreas

Answer 5

- Insulin & Glucagon – Human growth hormone – Follicle-stimulating hormone - anti diuretic hormone

Answer 6

modified amino-acid hormones are water soluble. Exceptions: thyroid hormones – lipid soluble • Secreted by, e.g. thyroid gland, pineal gland Have ine on the end Based on amino acids tryptophan and tyrosine

Answer 7

Tryptophan derived example: – Melatonin • Produced and secreted by pineal gland • Has roles in the sleep cycle • It is the only hormone known to be produced by the pineal gland • Tyrosine derived examples: – Thyroxine (T4), triiodothyronine (T3) • Produced and secreted by thyroid • Have roles in metabolic rate – Epinephrine (adrenaline), norepinephrine (noradrenaline) • Produced and secreted by medulla of adrenal gland • Have roles in cardiac output and blood sugar levels. Fight or flight response

Answer 8

Situated at base of brain, superior to (i.e. above) the pituitary gland • Key role in homeostasis • Primary roles … – Signals pituitary to start/stop hormone production – Produces a number of its own hormones

Answer 9

– Temperature regulation – Thirst/water intake – Hunger – Behaviour – Sleep cycles

Answer 10

Thyrotrophin Releasing Hormone - Triggers Thyroid Stimulating Hormone (TSH) in pituitary - Secretion of thyroxine from thyroid • Corticotrophin Releasing Hormone - Stimulates adrenocorticotrophic hormone (ACTH) in pituitary - Secretion of glucocorticoid hormones from adrenal cortex • Growth hormone releasing hormone - Stimulates human growth hormone - Stimulates growth of bones, muscles etc

Answer 11

Situated at base of brain, inferior to (i.e. below) the hypothalamus where it is connected via the infundibulum (or pituitary stalk) • Controlled by hormonal signals from hypothalamus

Answer 12

Causes hormone production and secretion which signal/control other organs of the endocrine system, notably thyroid gland, adrenal gland and gonads

Answer 13

Master gland

Answer 14

Anterior pituitary gland Posterior pituitary gland Both produce hormones - connected by intermediate lobe

Answer 15

– Adrenocorticotropic hormone (ACTH) • Maintains growth and development of the adrenal gland • Stimulates adrenal gland cortisol and epinephrine production – Follicle-stimulating hormone (FSH) • Involved in sexual development (ovaries and testes) • Control of menstrual cycle and control of sperm production – Luteinising hormone (LH) • Involved in sexual development (ovaries and testes) • Control of menstrual cycle and control of sperm production

Answer 16

– Antidiuretic hormone (ADH) • Produced by hypothalamus but stored & released by pituitary • Serves to decrease urine volume and increase blood pressure – Oxytocin • Uterus contraction during childbirth stimulates lactation

Answer 17

• Pineal gland is situated deep within centre of the brain • It sits within the region where the two halves (called hemispheres) of the brain join Produces hormone melatonin - derived from serotonin Melatonin known to control out circadian

Answer 18

• Butterfly-shaped gland located in the neck. • It is anterior to the trachea, inferior to the larynx • Composed of two lateral lobes connected by an isthmus (a constricted/narrowed ‘bridge’ between organs/part of) • Associated with 4 parathyroid glands in calcium deposition

Answer 19

– Regulation of metabolism • Thyroid hormones (TH) – Growth and development • Thyroid hormones (TH) – Calcium deposition in bone Calcitonin

Answer 20

Thyroid follicles

Answer 21

– Structural and functional units of the thyroid – Round with a wall of densely packed follicular cells – Follicular cells: Site of thyroid hormone production

Answer 22

1. Tetraiodothyronine (Thyroxine) (T4) 2. Triiodothyronine (T3) • T3 is more potent and is the main TH

Answer 23

Higher metabolic rate

Answer 24

under-production of thyroid hormones – Associated with weight gain, tiredness, impaired mental function

Answer 25

over-production of thyroid hormones – Associated with weight loss, irritability, increased body temperature

Answer 26

1. Tetraiodothyronine (T4) 2. Triiodothyronine (T3) 3. Calcitonin (CT)

Answer 27

C cells which produce calcitonin (CT) Serves to decrease blood calcium levels and increase calcium

Answer 28

Parafollicular cells Para - next to / adjacent to Adjacent to thyroid follicles

Answer 29

• Located on or near (hence, ‘para’) the posterior of the thyroid • Remember: thyroid has two lateral lobes, left and right • Parathyroid glands are roughly situated on or near each quadrant of the overall thyroid gland • They are located on the posterior region of the lobes • The parathyroid glands produce parathyroid hormone (PTH)

Answer 30

Raises blood calcium levels by removing calcium from bone The itwo hormones work together to maintain the balance of blood calcium levels

Answer 31

• Hypoparathyroidism = under-production of PTH – Causes decreased blood calcium levels → increased bone calcium. Can cause muscle pains/cramps, tiredness and mood alterations – anxiousness and depression • Hyperparathyroidism = over-production of PTH – Causes increased blood calcium levels → decreased bone calcium. Can cause joint and bone pains, leading to osteoporosis.

Answer 32

• Located in the chest between the lungs • Posterior to the breastbone (sternum) • Anterior to the primary blood vessels • Composed of two lobes, left and right Produces range of polypeptide hormones (thymopoietin)

Answer 33

Roles in production and maturation of T-lymphocytes (T- cells) from thymocytes (form of immune cell in thymus

Answer 34

Myasthenia gravis – Rare autoimmune disorder affecting neuromuscular system Pure Red Cell Aplasia (PRCA) – Another rare autoimmune disorder, affecting production of red blood cells (erythrocytes) in the bone marrow, causing anaemia • Anaemia:

Answer 35

• Situated within the abdomen, posterior to the stomach • Long and flat organ • Has endocrine and exocrine function

Answer 36

– Key role in digestion where is secretes digestive enzymes into the start of the small intestine (called the duodenum) – Enzymes for carbohydrate, lipid and protein breakdown

Answer 37

Primarily concerned with production of the hormones insulin and glucagon in regulation of blood glucose levels

Answer 38

Alpha cells - produce glucagon serves to raise blood glucose level Beta cells - produces insulin serves to decrease blood glucose level Delta cells - produce somatostatin also known as growth hormone inhibiting - inhibits insulin and glucagon Gamma cells ( PP cells) Produce pancreatic polypeptide regulates pancreatic function through reduction of appetite Episilon cells - produce gherlin serves to induce feelings of hunger also inhibits insulin secretion

Answer 39

Alpha and Beta Cells' Blood Sugar Response • Alpha cells detect blood glucose drop. • Release glucagon. • Glucagon circulates to liver for glycogen breakdown. • Increased blood sugar levels.

Answer 40

• Beta cells release insulin when blood glucose rises. • Insulin circulates throughout the body via the bloodstream, binding to cell surface insulin receptors. • Insulin binding causes glucose transport proteins to move from cytoplasm to plasma membrane. • Facilitated diffusion of glucose into cells reduces blood sugar levels.

Answer 41

• Adrenal glands are situated above the kidneys • One adrenal gland above each kidney • Each adrenal gland has two primary regions – Adrenal cortex (the outer region) – Adrenal medulla (the inner region)

Answer 42

Produce steroid hormones cortisol Cortisol plays role in stress response Promotes glucose production Glucose release into blood -> increased blood sugar levels

Answer 43

Aldosterone - role in the salt:water balance of the body where it targets the nephrons of the kidneys – It promotes reabsorption by the body of sodium and water from the tubules of the nephrons Decrease in urine vol Increase in bp

Answer 44

They are oval in shape and are situated either side of the uterus (womb) • Females have two ovaries which produce and release eggs (termed oocytes) • responsible for producing the hormones oestrogen and progesterone and their release is controlled by the hypothalamus

Answer 45

Oestrogen- stimulates breast development Development of reproductive organs Progesterone During pregnancy increases Helps maintain endometrium between ovulation and menstruation

Answer 46

• Male equivalent of ovaries. • Oval shape located in scrotum. • Suspended by spermatic cord. • Produce and release sperm. • Responsible for testosterone production.

Answer 47

• Secreted by Leydig cells of testes. • Promotes male reproductive organ development. • Stimulates public and chest hair production. • Promotes muscle growth and development. • Release controlled by hypothalamus and pituitary.

The Endrocrine System Flashcards

(72 cards)