The pituitary gland or hypophysis controls many aspects of human physiology. It is located at the base of the brain in SELLA TURCICA, a small cavity of sphenoid bone. It has two lobes – Anterior and Posterior. Intermediate lobe is present in many species, but in human beings, it is rudimentary. Anterior lobe is alsoContinue reading “ANTERIOR PITUITARY”


Pituitary is the proximal endocrine gland which links the Central Nervous System for NEUROENDOCRINE control of both metabolism and reproduction. These NEUROHORMONES control synthesis and secretion of Anterior Pituitary hormones which control Thyroid, Adrenal, Gonads, Growth & Lactation. NEUROHORMONES are synthesized in specialized neurosecretory cells which are concentrated within Hypothalamus. Neurohormones reach Anterior Pituitary GlandContinue reading “HYPOTHAMUS-PITUITARY CONTROL SYSTEM”


Conducting system of heart consists of Sinoarterial (SA) Node, Internodal Pathway, Atrioventricular (AV) node, His Bundle. Bundle branches and Purkinje Fibers. Conduction is Fastest in Purkinje Fibers. Depolarization initiated in SA node spreads radially through the atria. INTERNODAL & INTERATRIAL PATHWAYS TRANSMIT CARDIAC IMPULSES THROUGH THE ATRIA THE AV NODE DELAYS IMPULSE CONDUCTION FROM ATRIAContinue reading “CONDUCTING SYSTEM OF HEART”


PRIMARY FUNCTION OF RESPIRATION: SUPPLY SUFFICIENT OXYGEN & REMOVE CARBON DIOXIDE To sustain life, breathing must be cyclic, continuous and achieved by rhythmic contraction and relaxation of respiratory muscles by SOMATIC NERVOUS SYSTEM controlled by NEURAL & CHEMICAL factors. BASIC PLAN Some systems like HEART can function without NERVOUS SYSTEM , RESPIRATORY SYSTEM can notContinue reading “NEURAL REGULATION OF RESPIRATION”


Also called pulmonary membrane or alveolocapillary membrane. Its the tissues that separate the capillary blood from alveolar air. Exchange of gases takes place through this membrane and hence it plays a very important role in the respiratory process. STRUCTURE –> Consists of 8 layers CHARACTERISTIC FEATURES OF RESPIRATORY MEMBRANE –> Thickness (0.6 micrometre) & SurfaceContinue reading “RESPIRATORY MEMBRANE”


Thalamus in Greek means “Ante chamber” or “Inner chamber“. It was discovered way back in the 2nd Century AD, when Galen traced the optic-nerve fibers to an oval mass closely associated with the ventricles. It is considered as head ganglion of all sensory systems.It integrates & processes all sensory impulses. All sensory pathways (EXCEPTION – OlfactoryContinue reading “THALAMUS”


A diencephalic (bilateral) structure. It represents less than 1 % of the brain mass. Small in size but has two way communicating system with all levels of limbic system. Subdivision & nuclei of Hypothalamus CONNECTIONS Hypothalamus is connected to several areas of brain to serve several functions autonomic , visceral etc. Apart from neural connectionContinue reading “HYPOTHALAMUS”


LIMBIC –> Border/ Girdle. derived from limbus meaning RING. Previously called Rhinencephalon due to its relation to olfaction. Apart from Olfaction, it plays important roles in behaviour, emotion,motivational drives, memory as well as regulation of visceral functions –> Hence referred as –> VISCERAL BRAIN Limbic system is not a separate structure. It refers to aContinue reading “LIMBIC SYSTEM”