ANATOMY OF ENDOCRINE & REPRODUCTIVE SYSTEM

L2: GROSS ANATOMY OF PITUITARY, ADRENAL, THYROID AND PARATHYROID
GLANDS
 Endocrine glands are ductless glands that secrete hormones into the blood directly
 The hormones flow together with the blood and go to the target organ
 PITUITARY GLAND ( hypophysis cerebri )
- “ master gland “ that controls other endocrine glands
- Located in the hypophyseal fossa/pituitary fossa
- Lined by dura mater and covered by diaphragma sella
- Parts:
i. ADENOHYPOPHYSIS ( anterior pituitary )
 Pars distalis, pars intermedia, pars tuberalis
ii. NEUROHYPOPHYSIS ( posterior pituitary )
 Median eminence, infundibulum, pars nervosa
- Relations:
i. Superior: diaphragma sella, optic chiasma, floor of 3V
ii. Inferior: hypophyseal fossa, sphenoidal bone, air sinus
iii. Anterior: ant intercavernous sinus
iv. Posterior: post intercavernous sinus
v. Lateral: cavernous sinus & its content ( CN 3456 & ICA )
- Arterial supply: branch of ICA
i. Superior hypophyseal artery
 supply pars tuberalis, infundibulum
 form primary capillary plexus in median eminence
ii. Inferior hypophyseal artery – supplies posterior lobe
- Anterior pituitary hormones
i. Adrenocorticotropic: stimulates cortisol secretion by the adrenal cortex & promotes
its growth
ii. Prolactin: stimulates breast development & milk production, involved in testicular f
iii. Growth hormone: regulate body growth
iv. Thyroid-stimulating hormone: stimulate secretion of thyroid hormone
v. Follicular-stimulating hormone: stimulates the growth and development of ovarian
follicle, required for sperm production
vi. Luteinising hormone: formation of corpus luteum, secretion of testosterone
- Posterior pituitary hormones
Hormones synthesized in hypothalamus are transported down the axons to endings of PP
Hormones are stored in vesicles b4 released into circulation ( vasopressin & oxytocin )




 Adrenal gland

, - Located on superomedial aspect of kidney, enclosed in the renal fascia
- It is separated from the kidney by little fatty connective tissue
- Measurement: 5cm × 3cm × 1cm & 5gm in adult
- Right adrenal: pyramidal in shape
 Parts: apex, base, ant & post surfaces, med & lat borders
 Relations:
i. Base related to upper pole of the right kidney
ii. Anterior surface: liver (lat), IVC (med), duodenum (inf)
iii. Posterior surface: right crus of diaphragm
- Left adrenal: semilunar in shape
 Parts: upper & lower ends, ant & post surfaces, med & lat borders
 Relations:
i. Anterior surface: cardiac end of stomach, splenic artery, pancreas
ii. Posterior surface: kidney (lat), left crus of diaphragm (med)
- Adrenal cortex secretes aldosterone, cortisol, testosterone
- Adrenal medulla secretes epinephrine, norepinephrine
- Arterial supply:
 Sup suprarenal artery: from the inferior phrenic artery
 Mid suprarenal artery: from abdominal aorta
 Inf suprarenal artery: from renal artery
- Venous drainage:
 Right suprarenal vein: drain into IVC
 Left suprarenal vein: drain into left renal vein
- Nerve supply: celiac plexus & thoracic splanchnic nerves
- Lymphatic drainage: lateral aortic & lumbar lymph nodes
- Clinical importance:
i. Adrenal tumors (benign) leading to Cushing’s syndrome & Conn’s syndrome due to
overproduction of hormones (aldosterone & cortisol)

 Thyroid gland
- Located at the lower part of the front and sides of the neck opposite ( C5-T1 )
- Parts:
 Two right & left lateral lobes, extends from middle of thyroid c to 4 th tracheal ring
 Joined by central isthmus extending from 2-3 tracheal rings
 3rd pyramidal lobe projects upwards from the isthmus
 The pyramidal lobe connected to hyoid bone via levator glandulae thyroideae
- Coverings:
 Inner true capsule: formed by condensation of CT
 Outer false capsule: derived from pre-tracheal fascia
- Suspensory ligament of Berry:
 Thickened false capsule connecting med surface of the lateral lobe to cricoid c
 Moves thyroid swellings upwards during swallowing
- Have conical lobes with apex and base
- Relations: