Cerebral Ischemia: Molecular and Cellular Pathophysiology
Wolfgang Walz
Mar 1999 · Springer Science & Business Media
eBook
278
Halaman
reportRating dan ulasan tidak diverifikasi Pelajari Lebih Lanjut
Tentang eBook ini
The human brain represents about 2% of the body weight, yet it accounts for approximately 20% of aerobic metabolism. This high dependency on energy-consuming processes is mainly caused by the active transport of ions, which is necessary to compensate for the transmembrane ion currents that are part ofthe complex signaling processes in the brain. Ninety-five percent ofthe brain's ATP is derived from mitochondrial oxidative phosphorylation. Since that organ' s storage capacity for oxygen is minimal, any interruption of oxygen delivery to brain cells willlead to changes in membrane excitability and, there fore, to disruption of neuronal signaling within seconds. It seems that mamma lian brain is especially vulnerable to such an interruption, since oxygen deprivation leads to activation of ion channel mechanisms in neurons that impair their communications. Thus, the function of the brain as a coordinator of vital homeostatic reflexes, and complex body reactions to external challenges, depends critically on the rate of oxygen delivery and oxygen consumption. Oxygen delivery depends on two variables described in the Fick relation ship: volume flow rate ofblood and the arterial oxygen content. A reduction in either of these two variables will have serious effects on vital brain func tions. Reduction of arterial blood flow to the brain can be caused by cardiac arrest, shock, carotid occlusion, Of hypotension (global ischemia). Oxygen content is progressively decreased in asphyxia (including drowning).
Beri rating eBook ini
Sampaikan pendapat Anda.
Informasi bacaan
Smartphone dan tablet
Instal aplikasi Google Play Buku untuk Android dan iPad/iPhone. Aplikasi akan disinkronkan secara otomatis dengan akun Anda dan dapat diakses secara online maupun offline di mana saja.
Laptop dan komputer
Anda dapat mendengarkan buku audio yang dibeli di Google Play menggunakan browser web komputer.
eReader dan perangkat lainnya
Untuk membaca di perangkat e-ink seperti Kobo eReaders, Anda perlu mendownload file dan mentransfernya ke perangkat Anda. Ikuti petunjuk Pusat bantuan yang mendetail untuk mentransfer file ke eReaders yang didukung.
