Prolonged exposure to microgravity is known to invoke physiological changes which predispose individuals to orthostatic intolerance upon readaptation to the earth's gravitational field. Attenuated baroreflex responsiveness has been implicated in contributing to this inability to withstand orthostatic stress. To test this hypothesis, eight individuals were exposed to 15 days of simulated microgravity exposure using the 6° head-down bed rest model. Prior to, and after the simulated microgravity exposure, the following were assessed: a) aortic baroreflex function; b) carotid baroreflex function; c) cardiopulmonary baroreflex function; and d) the degree of interaction between the cardiopulmonary and carotid baroreflexes.
Ten caucasian male quadriplegics were compared with eight sedentary caucasian male controls in regards to left ventricular dimensions and mass obtained from echocardiograrns. The interventricular septum (IVS), left ventricular posterior wall (LVPW) and left ventricular internal diameter (LVII) were within normal limits for both groups. However, the INS in the SCI were significantly thicker than controls (p <0.05). Myocardial thickness was larger in SCI subjects (p <0.05). Absolute left ventricular mass (LVM) and total left ventricular volume was not different ( p > 0.05), but SCI subjects had significantly greater LVM to lean body mass ratios. Echocardiographically, SCI patients demonstrate concentric hypertrophy. This suggests adaptive response to chronic increase in afterload pressure secondary to their daily activities and muscle spasticity.
This dialog allows you to filter your current search.
Each of the Decades listed note their name and the number of records that will be limited down to if you choose that option.
This dialog allows you to filter your current search.
Each of the Years listed note their name and the number of records that will be limited down to if you choose that option.
This dialog allows you to filter your current search.
Each of the Months listed note their name and the number of records that will be limited down to if you choose that option.
This dialog allows you to filter your current search.
Each of the Department listed note their name and the number of records that will be limited down to if you choose that option.
This dialog allows you to filter your current search.
Each of the Discipline listed note their name and the number of records that will be limited down to if you choose that option.
This dialog allows you to filter your current search.
Each of the Degree Level listed note their name and the number of records that will be limited down to if you choose that option.