The Nuts and Bolts of the Endocrine System: Anatomy and Histology Roadshow Flashcards
What is the composition of the endocrine system?
hormone-secreting glands
Hormones are … molecules
mediator
The endocrine system is essential for
normal growth and development adaptation to internal and external environment contribute to the process of sexual reproduction
The nervous system and the endocrine system interact at what?
the hypothalamus (major controlling centre of the ANS)
What does the hypothalamus control? (3 things)
temperature circadian rhythms hunger
Each hormone elicits a response from any cell carrying a …
receptor sentitive for that hormone
Endocrine glands - do they have ducts?
vascularised?
ductless - hormone released to interstitial space - blood stream or lymphatic system
highly vascularised
Hormones affect other cells metabolism according to:
number of molecules available
number of receptors available
affinity hormone-receptor
Chemical classification of hormones: (3 main categories) + examples?
amine (adrenaline, noradrenalin, dopamine)
steroid (oestradiol, testosterone)
protein/peptide (ADH, oxytocin, insulin)
Nitric oxide is both … and …
neurotransmitter and hormone
What is this image showing?
Germ layers of developing embryo
Source of Steroid hormone
What is it derived from?
ovaries, testis, adrenal cortex
embryonic mesodermal tissue
Source of Protein/Peptide hormone
cells of what origin?
Adenohypophysis (pituitary) - ectodermal tissue of the oral cavity
Thyroid, Paraythyroids, Pancreas - cells of endodermal origin of GI tract
Scattered endocrine cells in epithelium of GI tract and lungs
Source of Amine hormone
cells of what origin?
Thyroid, adrenal medulla
cells of ectodermal origin
Where are discrete glands found? (4)
Hypophysis, thryoid, parathyroid, adrenal
Where are large glands found? (3)
they have both … and… function
kidneys, ovaries/testis, placenta
endocrine and exocrine
Diffuse endocrine system is composed of
scattered nerve cells with endocrine function
List the endocrine glands in the body? (10)
Pineal gland
Parathyroid gland
Hypothalamus
Thyroid gland
Pituitary gland
Adrenal gland
Thymus
Testis
Ovary
Pancreas
Other glands include:
ovaries/testes
pancreas/kidney/liver/thymus
skin, pineal gland, placenta etc
What is this image showing?
The hypophysis (pituitary gland)
What kind of gland is the hypophysis?
What is is suspended from?
compound gland - two main components
suspended from the hypothalamus by stalk or infundibulum
Where is the hypophysis located?
Sella turcica, a depression in the superior surface of the sphenoid bone
What is the function of the hypophysis?
What is it known as?
produces several hormones that influence activity of other endocrine glands (E.g. liver)
‘master’ endocrine gland
What is the sella turcica?
A depression in the superior surface of the sphenoid bone
Hypophysis gross anatomy
what are the two lobes?
two lobes
adenohypophysis - anterior lobe
neurohypophysis - posterior lobe
Hypophysis gross anatomy - it is no larger in size than that of what?
a pea
Adenohypophysis is the … part of the hypophysis
glandular
Neurohypophysis is the … part of the hypophysis
neural
The adenohypophysis is an outpouch of what?
what is the outpouch called?
ectoderm of oral cavity
Rathke’s pouch
The neurohypophysis is a downgrowth from
the diencephalon of the brain
What hormones does the neurohypophysis produce?
Oxytocin, ADH
What hormones does the adenohypophysis produce?
FSH, LH, TSH, etc
What is this image showing?
blood circulation of the hypophysis
Blood supply to the hypophysis - supplied by which 2 blood vessels? (branches of internal carotid)
Superior hypophyseal
Inferior hypophyseal
The superior hypophyseal supplies
median eminence
upper part of stalk
The inferior hypophyseal supplies
neurohypophysis
lower part of stalk
arteries supplying median eminence and stalk end as … …
capillary plexuses
Hypophysis - veins
capillary plexuses in median eminence and stalk ending are drained by …
These veins pass to what?
veins then form a … … plexus
portal veins (shown in image)
anterior lobe of pituitary
secondary capillary
Hypophysis - veins
Veins forming a secondary capillary plexus - setup provides a route for … substances released from the … to also reach the … lobe
neurosecretory
hypothalamus
anterior lobe
Hypophysis - control (Activity)
signals from the … are responsible for hormone release from both … and …
hypothalamus
adenohypophysis
neurohypophysis
What is this image showing?
Thyroid cartilage
Isthmus
The thyroid gland is a … gland in the neck
how much does it weigh?
whats its measurement?
bilobed
30g
4 x 2cm in size
The thyroid gland has … lateral lobes connected by an … that courses anterior to the …
2
isthmus
trachea
The thyroid gland lies just below the … … of thyroid cartilage to …/6 tracheal ring, immediately … to the trachea
olbique
5/6
anterior
The thyroid gland is derived from what?
It develops as a growth from the floor or …
endoderm
floor of pharynx, near base of tongue
The thyroid gland is under control from the … and …
hypothalamus (thyrotropin-releasing hormone)
Hypophysis (thyroid stimulating hormone)
The thyroid gland has an essential role in regulating what things?
tissue metabolism
growth and development
(T3, T4)
What is this image showing?
blood course of the thyroid gland
Thyroid - blood supply (arteries)
… thyroid from what?
… thyroid from what?
superior thyroid (from external carotid)
inferior thyroid (from subclavian)
Thyroid gland - blood drainage (veins) from an extensive plexus into the
… … vein
… vein
internal jugular vein
brachiocephalic vein
Thyroid gland - care in surgery - why? (2 things)
blood loss
recurrent nerve (from vagus) damage
What are the arrows pointing to (6)?
External carotid (Top arrow right)
Vagus nerve (Second arrow right)
Common carotid (third arrow right)
Recurrent nerve (fourth arrow right)
Superior parathyroids (top left)
Inferior parathyroids (bottom left)
‘Para’ = to the … of the thyroid gland
side - although some variation can occur
There are … parathyroid glands: … superior and … inferior; embedded in … of thyroid (posterior aspect)
what size are they?
4
2 superior, 2 inferior
capsule of thryoid - posterior aspect
grain of rice - very small - 40mg
The parathryoid glands develop mostly from cells originating from …rd/…th … pouches; migrate caudally with the …
3rd/4th pharyngeal pouches
thymus
Role of parathyroid glands - secrete … hormone which regulates … and … levels within homeostasis
parathryoid
calcium and phosphate levels
Inferior parathyroids travel … to lie … compared to superior parathyroids
further to lie lower
Parathyroid glands -
artery:
vein:
nerve:
artery - primarily inferior thyroid (also superior)
vein: superior, middle + inferior thyroid
nerve: from middle and inferior cervical ganglions
The parathyroid glands must be preserved during …
if removed what happens?
thyroidectomy; if removed blood calcium levels fall = muscles, including respiratory and laryngeal, go into tetanic contraction - death