Endocrine System Flashcards
List 5 functions of hormones
Control and regulate 1 reproduction 2 metabolism 3 growth 4 defence 5 homeostasis
What’s the thymus?
An organ involved in T cell maturation by the production of thymosin. Post puberty the thymus involutes. Located at the superior mediastinum.
Where do endocrine secrete?
In to the blood
What do exocrine glands have that endocrine do not?
Ducts
What’s the difference between neurocrine and endocrine.
Cell secrets into blood stream- endocrine
Nerve secretes at end terminal into blood stream - neurocrine
Name the three locations of neurocrine secretion:
Adrenal medulla
Anterior pituitary
Hypothalamus
Portal capillary systems are rare. Where are they found
Hepatic portal system
Hypothalamo-hypophyseal portal system
How do hormones regulate glands?
Positive and negative feedback loops
Thyroxine inhibits…
TRH AND TSH production
What are the principle effectors of the stress response ?
Hypothalamus
Anterior lobe of the pituitary
Adrenal gland
Chromaffin cells are found where and are considered as?
They are epitheliod cells found in the medulla considered as post synaptic neurons
What function does the pineal gland have?
Melatonin production
Gonadotrophin inhibition
What’s significant about pineal glands on imaging?
They calcify and so show up on X Ray in early adulthood
What 2 systems allow body system communication?
Nervous
Endocrine
Sympathetic nervous stimulation inhibits all digestive organs apart from which process in which accessory organ?
Glycogenolysis in the liver
What do your heart and lungs do if the sympathetic stimulus is increased?
Heart beats faster and harder
Lung- airways relax
Which spinal areas release sympathetic innervation?
Throracic
Lumbar
Are cranial nerves stimulated by parasympathetic or sympathetic control?
parasympathetic
Which branch of the autonomic nervous system stimulates urination by bladder contraction?
Parasympathetic
What autonomic control is vascular smooth muscle under and by which receptor type?
Alpha 1 - adreno receptor
Sympathetic control
In times of stress what do we want our vessels to do under sympathetic control.
Superficial vasoconstriction- minimise blood loss
Venoconstriction to increase cardiac return.
Prioritize blood flow to brain, heart and skeletal muscle.
Which two hormone categories are tyrosine derivatives?
Thyroid hormone
Catecholamines
Where are the receptors found for steroid hormones and thyroid hormone?
The nucleus
What is the produced in the hypothalamus?
ADH and oxytocin go to posterior pituitary for storage and release
G- Growth hormone (releasing and inhibitory) hormone
G- Gonadotrophic hormones
P- Prolactin Releasing hormone
T- Thyrotropin releasing hormone
A- Cortico releasing hormone (from Adrenals)
(Giant Gonads Prolong The Action is away of remembering the hypothalamus - ant pitutatry hormones)
What is stress?
Real or perceived threat to homeostasis that will activate our stress response involving endocrine, nervous and the immune systems to invoke behavioural and physical changes in an aim to survive.
What behavioural changes are seen in the stress response?
Increased awareness
Improved cognition
Euphoria
Enhanced analgesia
What are the physiological changes in a stress response?
Increased vascular tone
Increased resp rate
Decrease in vegetative functions - feeding, gigesting, growing, reproduction and immune functions
What hormones are released by the adrenal gland?
Medulla - adrenaline and nor adrenaline
Cortex -G Mineralocorticoids (aldosterone)
-F Glucocorticoids (cortisol)
-R Androgens
What does the adrenal gland help to do in fight or flight?
Mobilise glucose
Increase BP
Shut down all non emergency services in the body
Tell me which glands make what to result in cortisol release.
Hypothalamus releases cortotropin releasing hormone.
Ant. Pitatry releases Adreno- Cortico Tropic Hormone.
Adrenal cortex releases cortisol
What are the short term stress responses of adrenaline and nor-adrenaline?
Glycogen breaks down to glucose Increases BP Increase metabolism Increases respiration Changes in blood flow
What so mineral corticoids do?
Increase sodium retention
Increase blood volume and BP
What is the role of glucocoricoids?
Proteins and fats converted to glucose or used for energy
Increase blood sugar
Suppress immune system
What does light exposure do to melatonin release from the pineal gland?
inhibits it
How does the pineal gland know if its dark or light?
Neuronal pathway is retina- hypothalamus- pineal gland
Where is the pineal gland?
Midline
