integrative metabolism Flashcards
muscle fiber type that is multinucleated and striated with low glycogen storage and a rich capillary blood supply
type I skeletal muscle
brain derives its specialized, complex, and VLC lipids from what linoleic and alpha linolenic acids
cerebroside, gangliosides, plasmalogens, very long chain FA
two types of cells in the brain
neurons and neuroglia (supporting cells)
types of neuroglia cells
astrocytes (blood brain barrier), oligodendrocytes (myelination), and microglia (immune function)
supply of energy for brain in the well fed state
glucose
organ that uses high and consistent rate of O2 consumption
brain
state after a meal is called …
absorptive or post prandial state
what does brain use for energy during prolonged fast
ketone bodies
importance of brain using ketone bodies for energy
it spares the glucose allowing for a reduction in gluconeogenesis and helps to spare body protein from amino acid degradation
glucose and ketone bodies enter the brain via what typeof diffusion
facilitated diffusion
glucose uses what transporter to get into the brain
GLUT 1 and 3 (not insulin dependent)
ketone bodies use what transporter to get into the brain
monocarboxylate transporter (slower than GLUT’s and upregulated during starvation)
energy storage in the brain
none really …low glycogen (insignificant) and no TAGs
why can’t FA from adipose TAGs enter into the brain
they are attached to albumin and can’t cross the blood brain barrier but dietary FA can cross using specific transporters
types of molecules that can freely cross the blood brain barrier
small uncharged molecules and non polar substances through passive diffusion; essential FA and vitamins, proteins
why do some hydrophobic drugs pass slower than expected into the brain
because they attach to albumin and hence stay longer in the blood and can’t cross the BBB (ex: phenobarbitol)
why are amino acids that are neurotransmitters blocked from entry into the brain
brain synthesizes its own neurotransmitters (separation of somatic pool from neural pool)