Endocrine disorders Flashcards
What do endocrine hormones control
- metabolism
- growth and development
- adaptive responses (e.g., stress)
- hydration and electrolyte balance
- red blood cell production
- digestion and absorption
- reproduction
- activation of body defences
What does the hypothalamus link
The hypothalamus links the nervous
and endocrine systems via the
pituitary gland
What is the Posterior pituitary gland
The posterior pituitary is neural tissue,
connected to the hypothalamus via
the hypothalamic stalk or
infundibulum
What is the Anterior pituitary gland
Anterior pituitary is glandular tissue, connected to the hypothalamus via the hypophyseal portal system
the hypothalamus controls the release of pituitary hormones in two different ways
Posterior pituitary: action potentials travel down hypothalamic neuron axons, causing hormone release from the axon termini:
(1) Hypothalamic neurons synthesize oxytocin or antidiuretic hormone (ADH), which are then transported via axons to the posterior pituitary
(2) Oxytocin and ADH are stored in axon termini until hypothalamic neurons trigger release into blood vessels
What is Oxytocin
Oxytocin (peptide) acts on uterus to induce labour/promote contractions, and promotes breast milk ejection
What is ADH
ADH (peptide) also termed vasopressin, acts on kidneys to promote water resorption from forming urine back into blood
What are the main functions of the bodies non-reproductive endocrine organs
Main functions of non-reproductive endocrine organs
1. metabolism
2. growth and development
3. adaptive responses (e.g., stress)
4. hydration and electrolyte balance
5. red blood cell production
6. digestion and absorption
7. reproduction
8. activation of body defences
list the hormones produced by these endocrine hormones
Hypothalamus and pituitary gland produce:
1. Oxytocin or antidiuretic hormone (ADH)
2. Growth hormone (GH) (peptide) anabolic tissue-building protein with metabolic and growth promoting activities
3. Thyroid-stimulating hormone promotes normal development and secretory activity of the thyroid gland
4. Follicle stimulating hormone are gonadotrophic hormones that regulate the production of oocytes and spermatogonia
5. Adrenocorticotropic hormone (ACTH) acts on adrenals to promote corticosteroid release (glucocorticoids)
6. Luteinizing hormone (LH) are gonadotrophic hormones that regulate the production of oocytes and spermatogonia
7. Prolactin (PRL) stimulates milk production from the breasts
Thyroid gland hormones:
1. Thyroid Hormone
2. Thyroxine
4. triiodothyronine
5. calcitonin
Parathyroid:
1.Parathyroid hormone (PTH, protein hormone)
Adrenal cortex:
1. corticosteroids (e.g., mineralocorticoids, glucocorticoids, gonadocorticords) – synthesised from cholesterol
Adrenal cortex:
explain how disruptions to these endocrine hormones can lead to endocrine disorders
Hypo- and hyper hormone levels are often associated with endocrine disorders
What is Acromegaly
Acromegaly (Giantism): Growth hormone
hypersecretion
Disease pathology: Excessive GH secretion, promotes overgrowth of bones in the face, hands and feet. Often caused by pituitary tumour.
Slowly progressive disease resulting from
↑ GH and consequently ↑ insulin-like growth factor I (IGF1).
What is hyperthyroidism
Hyperthyroidism: overactive thyroid, autoimmune
disease
Disease pathology: Abnormal antibodies that mimic
TSH and promote continuous release of TH
What is graves disease PATHOPHYSIOLOGY
Thyroid glands in Graves’ patients often contain hypertrophied follicular cells
Thyroid-stimulating hormone receptor (TSHR) autoantibodies stimulate thyroid cells to hypersecrete T3 and T4
Autoantibodies are produced by local B cells and plasma cells controlled by T cells and are aided by insulin-like growth factor 1 (IGF1), originating in the liver.
T cells are activated by TSHR peptides on antigen-presenting cells (APCs), which might be the thyroid cells themselves or B cells, macrophages or dendritic cells in the vicinity.
what is Hypothyroidism
Hypothyroidism: underactive thyroid, insufficient
production of TH
Disease pathology: Primary (defect in thyroid gland),
secondary (defect in TSH or TRH release)
What is Hyperparathyroidism
Hyperparathyroidism: excess PTH, often caused
by tumour. 3rd most common endocrine disorder
Disease pathology: Hypercalcemia (high blood
Ca2+), resulting from Ca2+ leaching from bone, and
consequent bone softening. In severe cases,
bones appeared “moth-eaten” and are prone to
spontaneous fractures. Rise is blood Ca2+ impacts
nervous system, muscle function, and kidney
health.
