Flashcards
Pituitary Gland
Cards in this deck (105)
- 1Define 'endocrine glands'Organs that secrete hormones into the blood. They release 'chemical messengers'.
- 2Name the main endocrine glands of the human body (12)Hypothalamus
Pituitary
Pineal
Thyroid
Parathyroid
Thymus
Kidney
Pancreas
Adrenal
Ovaries
Uterus
Testes - 3Define 'non-classical endocrine tissues'Tissues that have main functions that are non-endocrine but they possess endocrine functions too
- 4Give an example of a non-classical endocrine tissueG.I. tract - releases CCK (inhibits stomach emptying) and lectins
- 5Hormone action is regulated at which 3 levels?Whole body level
Cellular level
Molecular level - 6Give examples of regulation of hormone action at whole body levelIonic and fluid balance
Metabolism
Growth and development
Reproduction
Coping with the environment - 7Give examples of regulation of hormone action at cellular levelCell division
Differentiation
Apoptosis
Secretion
Nutrient uptake
Motility - 8Give examples of regulation of hormone action at molecular levelGene transcription
Protein synthesis
Protein degredation
Protein conformation
Enzyme activity
Protein-protein interactions - 9Name the three ways hormones can actAutocrine
Paracrine
On far off organs - 10Define 'autocrine'Cell secretes a hormone or chemical messenger that binds to autocrine receptors on that same cell, leading to changes within the cell
- 11Define 'paracrine'Cell produces a signal to induce changes in nearby cells, altering the behaviour of those cells
- 12What are the three main types of hormones (chemical nature)?Steroid hormones
Peptide hormones
Amino acid-derived hormones - 13What are steroid hormones derived from?Cholesterol
- 14Name the two classes of steroid hormonesCorticosteroids
Sex steroids - 15Where are corticosteroids typically made?In the adrenal cortex
- 16Where are sex steroids typically made?In the gonads or placenta
- 17Give some examples of corticosteroids and sex steroidsTestosterone (sex)
Oestrogen (sex)
Cortisol (corticosteroid) - 18What are peptide hormones made from?Small chains of amino acids
- 19Give some examples of peptide hormonesGrowth hormone
Oxytocin
Parathyroid hormone - 20Give some examples of amino acid-derived hormonesThyroid hormones (thyroxine and triiodothyronine)
Catecholamines
Serotonin
Melatonin - 21What are the two ways by which hormones travel?'Free' in plasma
Bound to a carrier protein - 22How does being bound to a carrier protein benefit hormones?It prolongs their half-life in circulation (prevents them from being immediately excreted as soon as they are produced)
- 23Where is the receptor located for steroid hormones?In the cytosol or nucleus
- 24Where is the receptors located for peptide hormones?Cell surface
- 25What is the mechanism of action for steroid hormones?Bind DNA/ modify transcription
- 26What is the mechanism of action for peptide hormones?Bind to cell surface receptors which activate secondary messengers
- 27Is the speed of effect greater for steroid hormones or peptide hormones?Steroid hormones are slower
Peptide hormones are rapid - 28Compare the longevity of the effects of steroid hormones with that of peptide hormonesSteroid hormone effects are more permanent
Peptide hormone effects are temporary - 29Give two examples of steroid hormonesTestosterone
Oestrogen - 30Give two examples of peptide hormonesADH
Growth hormone - 31Where is the pituitary gland located?It is a small structure located at the base of the brain - lies inferior to hypothalamus with optic chiasm between
(Optic chiasm = crossing over of optic nerves)
- 32Because of its location, who is most likely to diagnose a pituitary tumour?Located below optic chiasm so an optician is most likely to diagnose
- 33What does the pituitary gland do?It releases hormones that, in turn, control the activity of the body's other hormone glands
- 34Label this diagram of the pituitary gland
- 35How is the anterior pituitary connected to the hypothalamus?By a series of blood vessels
(Portal blood vessels connect pituitary and hypothalamic capillary beds) - 36How is the posterior pituitary connected to the hypothalamus?By a series of nerve fibres that originate in the hypothalamus and transport hormones to the posterior pituitary (intraaxonal transport)
- 37How many hormones does the posterior pituitary lobe release?2
- 38Name the 2 hormones that are released by the posterior pituitaryOxytocin
Vasopressin (anti-diuretic hormone, ADH) - 39What are the two main functions of oxytocin?Controls milk release from the lactating breast
Controls uterine contraction at the onset of labour (can be administered exogenously if there are issues with the progression of labour) - 40What is the main function of vasopressin/ADH?Acts on kidneys to reabsorb water
- 41Where are oxytocin and vasopressing/ADH produced? Where are they released?Produced in the hypothalamus
Released by the posterior pituitary - 42Describe the events that occur when oxytocin binds to its receptors1. Oxytocin is a peptide hormone so activates secondary messengers
2. This raises intracellular calcium levels in the myoepithelial cells of the mammary gland
3. In response, the myoepithelial cells contract, which forces milk into ducts - 43Suckling is an example of what type of reflex?Neuroendocrine reflex
- 44Describe the stages of the neuroendocrine reflex of suckling1. As soon as the child attaches to the breast, nerve impulses sent to hypothalamus
2. Hypothalamus produces and releases oxytocin to posterior pituitary
3. Oxytocin released into circulation by posterior pituitary and interacts with receptors of alveoli
4. Alveoli contract, causing milk to be expressed - 45What are the two things that ADH/vasopressin regulates?Blood osmolarity
Urine output - 46Describe the stages of ADH/vasopressin action1. Increased plasma osmolarity (e.g. haemorrhage/dehydration)
2. Osmoreceptors in hypothalamus stimulated
3. Hypothalamus produces and releases ADH to posterior pituitary
4. Posterior pituitary releases ADH into circulation
4. Water is selectively reabsorbed in the distal convoluted tubule and collecting ducts of the kidneys
5. Urine becomes more concentrated and urine volume decreases = decreased plasma osmolarity (which slows release of ADH)
- 47What does ADH stimulate the production of (which results in the collecting duct being more permeable to water)?Aquaporins
- 48Why does alcohol increase urination?Alcohol inhibits the secretion of ADH from the posterior pituitary - aquaporins not produced in collecting duct
- 49What is the anterior pituitary described as?The regulator of the endocrine system
- 50How many hormones does the anterior pituitary secrete?6
- 51Name the 6 hormones secreted by the anterior pituitaryGrowth hormone
Prolactin
Adrenocorticotropic hormone (ACTH)
Thyroid-stimulating hormone (TSH)
Follicle-stimulating hormone (FSH)
Luteinising hormone (LH) - 52Most of the hormones secreted by the anterior pituitary are tropic hormones. Explain what this means.Tropic hormones regulate the secretions of other endocrine organs (their targets are other endocrine glands)
- 532 of the hormones secreted by the anterior pituitary are not tropic hormones. Name them.Prolactin
Growth hormone - 54Why is it possible for the anterior pituitary gland to produce so many different hormones?Because of its cellular makeup (5 cell types)
- 55Name the 5 different cell types making up the anterior pituitary gland and their distributionSomatotrophs (50%)
Lactotrophs (15-20%)
Corticotrophs (15-20%)
Gonadotrophs (10%)
Thyrotrophs (5%) - 56What hormones do somatotrophs produce?Growth hormone
- 57What hormone do lactotrophs produce? What does this hormone do?Prolactin
Stimulates milk production - 58What hormone do corticotrophs produce?Adrencorticotropic hormone (ACTH)
- 59What hormone do gonadotrophs produce?Follicle stimulating hormone (FSH)
Luteinising hormone (LH) - 60What hormone do thyrotrophs produce?Thyroid-stimulating hormone (TSH)
- 61What are the principle target organs of FSH?Ovaries
Testes - 62What are the principle target organs of LH?Ovaries
Testes - 63What is the principle target organ of ACTH?Adrenal glands
- 64What is the principle target organ of TSH?Thyroid gland
- 65What is the principle target organ of prolactin?Mammary glands
- 66What are the principle target organs of growth hormone?Bone
Skeletal muscle
Liver - 67What is the name of the hormones that control the release of hormones from the hypothalamus to the anterior pituitary?Releasing hormones
- 68Which releasing hormone stimulates ACTH?Corticotrophin-releasing hormone (CRH)
- 69Which releasing hormone stimulates FSH and LH?Gonadotrophin-releasing hormone (GRH)
- 70Which releasing hormone stimulates TSH?Thyrotrophin-releasing hormone (TRH)
- 71Which releasing hormone stimulates growth hormone?Growth hormone-releasing hormone (GHRH)
- 72Which releasing hormone inhibits prolactin?Dopamine (DA) - everyone has high levels unless breastfeeding
- 73Which releasing hormone inhibits growth hormone?Somatostatin
- 74Normal growthBirth-2 years: nutrition
2-11 years: GH, nutrition (insufficient GH = short stature)
Puberty: GH, sex hormones, nutrition (insufficient GH = short stature) - 75What does the extent of growth also depend on?Other hormones
- 76Which other hormones does growth depend on?Thyroxine (lack inhibits growth)
Cortisol (excess inhibits growth)
Insulin (excess stimulates growth) - 77Is growth hormone anabolic or catabolic?Anabolic
- 78What does growth hormone do to the uptake of glucose by cells?Reduces uptake of glucose so it is conserved for the CNS
- 79Describe the direct metabolic effects of GH on muscle- Decreases glucose uptake
- Stimulates amino acid uptake/protein synthesis
- Inhibits protein breakdown = increased muscle mass - 80Describe the direct metabolic effect of GH on adipose tissue- Decreases glucose uptake
- Increases lipolysis = decrease in fat deposits - 81Describe the metabolic effect of GH on the liver- Increases gluconeogenesis
- Increases protein synthesis
- Stimulates IGF (insulin-like growth factor) production - 82What is GH vital in protecting you from? Why?Hypoglycaemia
Because it stops fat and muscle uptaking glucose in circulation and conserves it for the CNS - 83Describe the actions of GH via insulin-like growth factors (IGF)Skeletal growth - cartilage formation (increase chondrocyte mitosis and matrix production) and bone deposition (lengthening and thickening)
Soft tissue growth - protein synthesis and cell proliferation - 84Why will taking growth hormone as an adult not increase height?Growth plates (made of cartilage) fuse so bone response to GH ceases
- 85What are some of the symptoms of somatopause (natural decline in GH)?Decrease in lean body mass
Decline in bone mineral density
Increase in body fat
Sleep disturbance - 86Name some factors that stimulate growth hormone releaseStress
Exercise
Fasting
Sleep
Hypoglycemia
Amino acids
Sex hormones - 87Why does exercise stimulate the release of GH?To conserve what glucose we have so that it does not affect the CNS (when exercising, we are at risk of becoming hypoglycaemic as the body uses up glucose)
- 88What is gigantism usually the result of and in what age group is it most common?Usually the result of a pituitary tumour secreting excess growth hormone
Usually in children - 89What is gigantism?Abnormally high linear growth due to excessive action of IGF while the epiphyseal growth plates are open (childhood)
- 90Why are body proportions normal in gigantism?Because soft tissues are also affected
- 91What is acromegaly?Increased growth hormone later in life after fusion of epiphyseal growth plates
- 92What are some of the physical features of acromegaly?- Coarse facial features
- Enlarged hands and feet
- Protruding jaw and separation of teeth
- Enlarged tongue and thickened lips
- Deep voice
- Cardiomegaly
- Diabetes - 93What is the difference between GH insufficiency in adults and in children?In adults, GH insufficiency has no major symptoms
In children, there are various symptoms - 94What is the condition of GH insufficiency in children called?Pituitary dwarfism
- 95What are the symptoms of pituitary dwarfism?- Slow growth rate below 3rd centile on age/heigh or bone chart
- Normal body proportions
- Poor muscle development, excess subcutaneous fat - 96What are some of the dental-related symptoms that could present as a result of growth hormone disorders?- Hypo- and hyper-pituitarism
- Decreased facial and cranial base growth
- Gaps, delayed eruption, incomplete root formation
- Overgrown gum tissue
- Missing teeth - 97Name the hormones secreted by the hypothalamus.Releasing hormones - GHRH, CRH, TRH, GnRH, vasopressin
Inhibitory hormones - somatostatin, dopamine - 98Name the hormones secreted by the pituitary gland.- Growth hormone
- Prolactin
- ACTH, MSH
- TSH
- FSH and LH
- Oxytocin
- Vasopressin - 99Name the hormones secreted by the pineal gland.- Melatonin
- Vasopressin - 100Name the hormones secreted by the thyroid gland.- Thyroid hormones (T₃ and T₄)
- Calcitonin - 101Name the hormone secreted by the parathyroid glands.Parathyroid hormone
- 102Name the hormones secreted by the adrenal glands.Adrenal cortex - cortisol, aldosterone, adrenal androgens
Adrenal medulla - adrenaline, noradrenaline - 103Name the hormones secreted by the pancreas.- Insulin
- Glucagon - 104Name the hormones secreted by the ovaries.- Oestrogens
- Progesterone - 105Name the hormone secreted by the testes.Testosterone
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- Undergraduate Other Flashcards on Pituitary Gland, created by Riya X on 06/07/2021.
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