Chapter 2 - Chemical Messengers

Question 1

exocrine glands

Answer 1

💚 secrete into duct

💚 duct carries secretion to body surface/body cavities

💚sweat glands
💚mucous glands
💚salivary glands
💚glands of alimentary canal

Question 2

endocrine glands

Answer 2

💚 secrete hormones

💚 secrete them into extracellular fluid of cell that makes up gland

      ⚫ secretion then passes into capillaries/bloodstream

Question 3

The Endocrine Glands

Answer 3

💚 hypothalamus 
💚 pituitary
💚 pineal
💚 thyroid 
💚 parathyroid 
💚 thymus  
💚 adrenal glands 
💚 pancreas
💚 gonads

Question 4

Hormones

Answer 4

💚 secretion of an endocrine gland

💚 proteins and amines
💚 steroid

💚 transported in blood

💚 can affect all cells of body or specific cells (target cells)/organs (target organs)

Question 5

paracrines

Answer 5

💚 local hormones

💚 diffuse from cells to adjacent cells

💚 move through extracellular fluid (not bloodstream)

💚 for cells to communicate with other cells

Question 6

protein and amine hormones

Answer 6

💚 attach to receptor proteins in MEMBRANE of target cell

💚 receptor proteins
☑️ are specific
☑️ only a certain amount
☑️ different cells have different types and amounts

💚 hormone ➕ receptor ➡️ secondary messenger substance

secondary messenger substance
                ☑️ diffuses through cell 
                ☑️ activates particular enzymes

Question 7

steroid hormones

Answer 7

💚 combine with receptor protein INSIDE CELL
(mitochondria, nucleus, other organelles)

hormone-receptor complex 
                    ☑️ activates genes 
                    ☑️ the genes control forming of particular protein

Question 8

Hormones can…

Answer 8

1️⃣ activate certain genes in nucleus

2️⃣ change shape of enzyme (so it’s turned ON or OFF)

3️⃣ change rate of production of an enzyme

      ☑ done by changing rate of transcription/translation

Question 9

enzyme amplification

Answer 9

💚 production of thousands of enzymes via bondage of hormone to receptor

hormone triggers cascading effect

➡️ no. of molecules involved increases x1000s for each step along metabolic pathway

💚 small stimulus = very large effect

Question 10

hormone clearance

Answer 10

1️⃣ hormone molecules broken down

    ☑️ in liver/kidneys 
    ☑️ some in target cells 

2️⃣ degraded hormones secreted

    ☑️ bile 
    ☑️ urine

Question 11

Negative feedback system

Answer 11

💚 control of hormone secretions

☑️ regulates hormone secretions
☑️ response produced
➡️ opposite of stimulus that caused the secretion

☑️ regulating factors from hypothalamus
➡️ regulate function of pituitary

☑️ releasing factors from hypothalamus
➡️ stimulate release of a hormone OR inhibiting factors

Question 12

Hypothalamus

Answer 12

💚 regulating and maintaining internal environment

    ☑️ body temperature 
    ☑️ water balance 
    ☑️ heart rate 

💚 located at the base of the brain

Question 13

Pituitary gland

Answer 13

💚 absolutely vital to internal functioning of body

💚 anterior and posterior lobe

💚 underneath and connected to hypothalamus
➡️ infundibulum

Question 14

Anterior lobe of pituitary

Answer 14

💚 releases hormones that regulate bodily activities

💚 secretions controlled by releasing/inhibiting factors from hypothalamus
(extracellular fluid -> bloodstream)

💚 connected to hypothalamus by complex network of blood vessels

💚 FLATPEG

Question 15

Hormones released by anterior lobe

Answer 15

💚 FHS
💚 LH
💚 ACTH (adrenocorticotropic hormone)
💚 TSH 
💚 Prolactin 
💚 Endorphins*
💚 Growth hormone (GH)

Question 16

Posterior lobe

Answer 16

💚 not a true gland

   ➡️ release hormones produced by hypothalamus 

💚 connected by special neurosecretory cells (neurons)

   ➡️ hormones produced in these cells 
   ➡️ stored ready for release in posterior 
          ↪️ then released into bloodstream

Question 17

Hormones produced in posterior

Answer 17

💚 oxytocin

💚 anti-diuretic hormone

Question 18

Pineal gland

Answer 18

💚 secretes melatonin
➡️ regulation of sleep patterns
➡️ stimulated by darkness and inhibited by light

💚 located deep inside brain, tiny

Question 19

Thyroid gland

Answer 19

💚 in the neck

💚 two lobes on either side of trachea

💚 secretes thyroxine
➡️ controls body metabolism

Question 20

Parathyroid glands

Answer 20

💚 four

💚 embedded in rear surface of lobes of thyroid

💚 secrete parathyroid hormone (PTH)

         ➡️ controls calcium and phosphate levels in blood

Question 21

Thymus

Answer 21

💚 located in chest just above the heart, behind sternum

💚 secretes hormones called thymosins

                         ➡️ maturation of T-lymphocytes 

💚 shrinks after puberty

Question 22

Adrenal glands

Answer 22

💚 one above each kidney

💚 each adrenal gland has an
☑️ adrenal cortex (outer)
☑️ adrenal medulla (inner)

Question 23

Adrenal cortex

Answer 23

💚 produce corticosteroids
(20 different hormones, 2 main ones)

1️⃣ aldosterone 
       (kidneys - decr sodium/incr potassium in urine)

2️⃣ cortisol 
       (helps promote normal metabolism, withstand stress, repair)

Question 24

Adrenal medulla

Answer 24

💚 adrenaline - sympathetic division, fight or flight

💚 noradrenaline - similar to adrenaline

                             ☑️ increases rate and force of heartbeat

Question 25

Pancreas

Answer 25

💚 just below stomach, alongside duodenum 💚 both and endocrine and exocrine gland 💚 exocrine ☑️ digestive enzymes 💚 endocrine ☑️ cells (islets of Langerhans/ pancreatic islets) secrete: 1️⃣ insulin - reduces glucose in blood 2️⃣ glucagon - increases glucose in blood

Question 26

Gonads

Answer 26

💚 androgens ☑️ male sex hormones ☑️ testes 💚 oestrogen and progesterone ☑️ female sex hormones ☑️ ovaries

Question 27

Other endocrine tissues

Answer 27

💚 stomach and small intestine ☑️ secrete hormones coordinating exocrine glands of digestive system 💚 kidneys ☑️ ethryropoietin (EPO) ➡️ stimulates production of RBCs by bone marrow 💚 heart ☑️ hormone that helps reduce blood pressure 💚 placenta ☑️ hormones maintaining pregnancy (development of foetus, stimulate mothers mammary glands)

Question 28

Thyroxine

Answer 28

💚 increases metabolic rate 💚 target cells: most cells 💚 thyroid gland

Question 29

Parathyroid hormone

Answer 29

💚 increases calcium levels in blood 💚 target cells: bones, kidneys 💚 parathyroid glands

Question 30

Thymosins

Answer 30

💚 stimulates development and maturation of T-lymphocytes (immune) 💚 target cells: T-lymphocytes 💚 thymus gland

Question 31

Aldosterone

Answer 31

💚 increases reabsorption of sodium ions, increases excretion of potassium ions 💚 one of corticosteroids 💚 target cells: kidney 💚 adrenal cortex

Question 32

Cortisol

Answer 32

💚 promotes normal metabolism 💚 helps body with stress 💚 promotes repair of damaged tissues 💚 target cells: most cells 💚 one of corticosteroids 💚 adrenal cortex

Question 33

Adrenaline and noradrenaline

Answer 33

💚 prepares body for fight-or-flight responses 💚 reinforces effects effects of sympathetic nervous systems 💚 target cells: most tissues 💚 adrenal medulla

Question 34

Insulin

Answer 34

💚 stimulates uptake of glucose (lowers BSL) 💚 target cells: most cells 💚 pancreas

Question 35

Glucagon

Answer 35

💚 stimulates breakdown of glycogen and fat (increases BSL) 💚 target cells: liver and fat storage tissues 💚 pancreas

Question 36

Androgens

Answer 36

💚 stimulate sperm production 💚 growth of skeleton and muscles 💚 male sexual characteristics 💚 target cells: many tissues 💚 testes

Question 37

Oestrogens

Answer 37

💚 stimulate development of female characteristics 💚 regulate menstrual cycle 💚 target cells: many tissues 💚 ovaries

Question 38

Progesterone

Answer 38

💚 regulates menstrual cycle 💚 regulates pregnancy 💚 prepares mammary glands for milk secretion 💚 target cells: uterus and mammary glands 💚 ovaries

Question 39

Hormones of the anterior lobe

Answer 39

💚 FSH ☑️ ovaries: growth of follicles ☑️ testes: production of sperm 💚 Luteinising hormone ☑️ ovaries: ovulation, maintenance of corpus luteum ☑️ testes: secretion of testosterone 💚 Growth hormone ☑️ all cells ☑️ growth and protein synthesis 💚TSH (thyroid