ABSTRACT
Feather follicle movement control was studied on feathers of the pectoral tract in the anaesthetized chicken. Dissection of nerves leading to the follicles showed that their origin was at least partially in the sympathetic ganglia. Reflectoric ruffling of feathers could be obtained after adequate stimulation. Intravenous injections of drugs in doses which influenced the circulation gave the following results: Adrenaline caused erection of feathers which was abolished by phentolamine. Noradrenaline caused up and down movements after injection only at high doses. Similar results were obtained by placing of skin pieces in saline containing the drugs. The reaction to drugs was typical always for a given group of feathers. Killing of birds and anaesthesia caused general erection of feathers which was not abolished by phentolamine. The findings suggest that adrenergic synapses are involved in feather follicle movement control, but at least another mechanism (CNS) regulates feather follicle movement.
Subject(s)
Chickens/physiology , Animals , Feathers/physiology , Movement , Muscles/physiologyABSTRACT
It was found that most feather follicles posses more than a single muscle system but only single nerve endings were observed in a feather follicle. It seems that muscles exist which antagonize each other. Anastomoses of nerves originating from different sources and flowing of mixed nerves into the feather follicle could explain the antagonistic action of the muscles on the feather follicle.
Subject(s)
Feathers , Muscle Contraction , Skin/anatomy & histology , Animals , Chickens , Muscles/innervation , Nerve Endings/physiology , Skin/innervationABSTRACT
Selective utilization of carbohydrates and FFA by the heart was studied on the open-chest dog preparation. The heart was paced at frequencies from 120-240/min, and arterial and coronary venous blood samples were taken at these frequencies both during normal ventilation and hypoxia (arterial PO2 similar to 55 mmHg). The concentrations of glucose, lactate, pyruvate, and FFA were determined, and substrate utilization was calculated from these values and coronary blood flow. It was found that increased heart rate, particularly during hypoxia, increased utilization of both glucose and FFA. However, the relative amount of the energy produced from glucose utilization was minimal during hypoxia and most glucose underwent glycolysis only. Thus, whereas in control conditions of the relation between carbohydrate and FFA was about 60% to 40% during hyposia and high frequency the relation was reversed and almost 90% of all energy produced was supplied by FFA.
