Endocrine Flashcards
(25 cards)
What are Glands
- Group of epithelial cells that produce secretions
- If its distributed through a duct like earwax, mucus, saliva, digestive juices = Exocrine
- If its distributed directly into the blood like Hormones this is called Endocrine
Define the Endocrine system
- Glands are widely separated withour physical contact
- Crucial in cell growth and metabolism
- Hormones are released either directly through the Hypothalmus and pituitary glands, or indirectly by stimulus i.e. BM
- Works on a Negative Feedback system
Two types of Hormone are
- Lipid Based (action occurs over time)
Glucocoticoids = Steriods
Mineralocorticoids = Minerals
Thyroid
- Peptide Based (instantly happens) Adrenaline Noradrenaline Insulin Glucagon
Define what the job of Nonsteriod Hormones are
- Bind onto the receptor cell but never enter it
- Changes the shape of the receptor site
- Once through the cell membrane they activate the G-protein
Types of Endocrine Stimuli
- Humoral Stimulus
- Neural Stimulus
- Hormonal Stimulus
What is Humoral stimulus
- Negative feedback loop
- It detects a change in the blood and reacts
- ie The pancreas
What is Neural Stimulus
- Hormonal response to a nerve impulse
- ie Your eyes see a tiger and send a response to the brain to release Noradrenaline
What is Hormonal Stimulus
- Hormones arrive from somewhere else causing a reaction
What are the jobs for the Hypothalmus and Pituitary Glands
- Hypothalmus controls the release of hormones from both Anterior and posterior pituitary glands
- Control most other endocrine glands
- Hormones released by Hypothalamus
Dopamine,
Somatostain
Vasopressin - Pituitary Gland Hormones
Prolactin - Breast Growth
Oxytocin - Uterine contractions
Growth Hormone (GH) - Regulates metabolisim
Thyroid stimulating Hormone (TSH) - Secretion of T3 and T4 to stimulate growth
Adrenocorticotrophic (ACTH) - Secretes Glucocorticoids
Follicle Stimulating Hormone (FSH) - Production of sperm, ovulation
Luteinising (LH) - Progesterone
Antidiuretic (ADH) - Smooth muscle contraction
What sre the twon lobes of the pituataruy gland and define them
- Posterior
Formed of nervous tissue
Hormones released directly into the blood - Anterior
Carries releasing hormones and inhibiting hormones secreted by the hypothalamus
Where is the thyroid gland and its function
- In the neck level with 5,6,7th Cervical vertebrae
- Takes up the iodine from the blood which is crucial in formation of hormones
- Secretes T3 and T4 which increases Metabolic rate
- Enhances the effect of adrenaline
- Essential for growth and deveolpment of skeletal and nervous systems
What are the two thyroid disorders
- Hyperthyroidism Excessive levels of T3 and T4 Main effects are due to increased metabolic rate - Weight loss, good appetite - Tachycarida - Warm sweaty skin - Diarrhoea
- Hypothyroidism Deficiency of T3 and T4 Low metabolic rate - Weightgain, anorexia - Depression, mental slowness - Dry skin - Bradycardia - Cold skin - Constipation
Job of the Parathyroid gland
- Regulates blood calcium by increasing calcium reabsorton in the small intestine
- If inadequate stimulates Oesteoclasts to release calcium stored in bone
- Normal levels of calcium are needed for
Muscle contractions
Nerve Impulses
Blood clotting
Enzyme Action
Explain what the Adrenal glands are
- Are formed with a Cortex and Medulla, the cotex portion of the adrenal gland is essential for life the medulla is not
- Cortex produces corticosteriods
- Medulla produces Adrenaline
What are the three groups of Corticosteroids
- Glucocorticoids
- Mineralocorticoids
- Sex Hormone
What do Glucocorticoids do
- Cortisol - Essential for regulating metabolism and response to stress
- Controlled in a negative feedback system from the hypothalmus and pituitary glands
- Anti inflammatory, suppression of the immune system, response to wound healing
What do Mineralocorticoids do
- Aldosterone - Regulation of BP - Stimulation of the reabsortion of Sodium and excretion of potassium into the kidneys
- Regulated by potassium on the blood, when it rises aldosterone is released.
Explain what happens in Low BP/ Shock
- Baroreceptors in kidney and arch of aorta pick up low BP
- Relase of RAAS
- Hypothalmus and pituatory gland release ADH, which means sodium is retained and the kidneys retain the water
- Cardiovascular centre increases the sympathetic response, increasing HR and PR
- All the above work together to increase BP
What does the Adrenal medulla main reason
- Secretes Adrenaline in resposne to sympathetic stimulation
- Prolongs and augments the sympathetic response
- Medulla cortex provides the prolonged response to fight or flight response
What is Addisons Disease
- Distruction of the Adrenal cortex
- Hyposecreetion of Glucocorticoids and Mineralocorticoids
Effects of Addisons Disease
- Muscle weakness and wasting
- GI disturbances
- Increased Skin Pigmentation
- Listleness and tiredness
- Hypoglycaemia
- Confusion
- Electrolyte imbalance
- Chronic Dehydration
Presentaion and Management of Adrenal Crisis
Presentation
- Acutly ill
- Hypotension especially when postural
- Confused/weak
- Pyrexia
- Arrhythmia
- Progress into Delirium and Seizure
Management
- ABCD approach
- Time Critical
- Known Addisons
- Correct AB problems
- 100mg Hydrocortisone
- If shocked fluid replacement
- Correct Hypoglycaemia
Recap Mineralocorticoids response
- Hypothalmus and Anterior pituitary
- Adrenal cortox response
- Mineralcocortoids produced
- Salt water retention, increase in Blood volume
Recap Glucocortoids response
- Hypothalmus and Anterior pituitary
- Adrenal cortox response
- Glucocortoids
- Increase BGM
- Increase Fat and Protein Breakdown
- Decrease Inflammatory response
- Decrease Immune response
