Abstract The intracranial pressure (ICP) is simply the hydrostatic pressure within the skull, reflecting the pressure of the cerebrospinal fluid (CSF) and brain parenchyma. At rest in a normal supine…
Abstract In the adult, cerebral blood flow (CBF) is typically 15% of the resting cardiac output (approximately 750 mL/min). CBF is commonly expressed in terms of the weight of brain…
Abstract The nervous system is a complex network of specialised cells called neurons, which coordinate and control the other organ systems. Chapter 44 Neuronal Structure and Function What are the…
Abstract The blood–brain barrier (BBB) is a physiological, cellular and metabolic barrier at the level of the cerebral capillaries. Their permeability properties restrict the free movement of substances between the…
Abstract The brain performs complex sensory, motor and higher functions, coordinating the activity of other body systems. It has a high metabolic activity, receiving 15% of the resting cardiac output,…
Abstract Cerebrospinal fluid (CSF) is the transcellular fluid located within the cerebral ventricles and subarachnoid space that bathes the brain and spinal cord. CSF has a number of functions. Chapter…
Abstract Exercise is a major physiological challenge to the body, affecting all the main body systems. An accompanying increase in muscle metabolic rate results in an increase in O2 demand…
Abstract Surgery places a person’s body under physiological stress: the magnitude of the stress response is proportional to the severity of the surgical trauma. The surgical stress response increases an…
Abstract The Valsalva manoeuvre is performed by forced expiration against a closed glottis. It is attributed to Antonio Valsalva (1666–1723), who described it as a test of Eustachian tube patency…
Abstract The organs require a fairly constant mean arterial pressure (MAP) to ensure adequate perfusion. Some organs (most notably the brain, heart and kidneys), despite fluctuations in MAP, intrinsically maintain…
