The mitral valve, as an active flap, forms the major part of the left ventricular inflow tract and therefore plays an important function in many aspects of left ventricular performance. The anterior leaflet of this valve is the largest and most ventrally placed of two leaflets that come together during ventricular systole to close the left atrioventricular orifice. Various neurotransmitters are...

The VIIth cranial (facial) nerve is largely motor in function (some sensory fibres from external acoustic meatus, fibres controlling salivation and taste fibres from the anterior tongue in the chorda tympani branch). It also supplies the stapedius (so a complete nerve lesion will alter auditory acuity on the affected side). From the facial nerve nucleus in the brainstem, fibres loop around the ...

There are many techniques for the treatment of hip dysplasia, and novel research is currently being undertaken in the hope of obtaining more efficient and less traumatic techniques. The denervation of the hip joint capsule is a simple and effective technique that allows recovery of the functional activity of the affected limbs in significantly less time than other techniques. This surgical proc...

1. Two aspects of nerve-muscle development were studied in neonatal rats, the role of competition between motor neurones during the elimination of polyneuronal innervation, and the dependence of muscle fibre production upon the number of motor neurones innervating the muscle. 2. Rat lumbrical muscles were partially denervated at birth by cutting the lateral plantar nerve. Many muscles remained ...

Investigations of the nerves of the rabbit lung, by light and electron microscopy, showed a dense acetylcholinesterase-positive innervation of the bronchi through the bronchiolar level. Large nerve bundles were found to decrease in size as they progressed from extrachondral to subchondral connective tissue, forming complex networks of mostly terminal fibres in the muscle layer. In several insta...

The VIIth cranial (facial) nerve is largely motor in function (some sensory fibres from external acoustic meatus, fibres controlling salivation and taste fibres from the anterior tongue in the chorda tympani branch). It also supplies the stapedius (so a complete nerve lesion will alter auditory acuity on the affected side). From the facial nerve nucleus in the brainstem, fibres loop around the ...

Ultrathin sections of a rabbit scrotal syphiloma were examined by electron microscopy. Treponemes were observed in the endo-, peri-, and epineurium of the nerve fibre. The significance of these findings, in that infection may be transmitted via the nerve fibres and pain reduced by damage to the afferent fibres, are discussed.

Axons grow out along predictable routes of specific destinations. An EM study of the early development of one of the main chick wing nerves - the interosseous nerve - helps to show how they do it. The growing tip of the nerve appears frayed, consisting of nerve fibres occurring singly or in small bundles, taking slightly divergent paths. Most of these pioneer nerve fibres have the characteristi...