Midterm Part 2 Flashcards
True or false
polar molecule, such as steroids can easily diffuse through the cell membrane
FALSE
Nonpolar molecule, such as steroids can easily diffuse through the cell membrane
True or false
Most drugs and polar molecules are larger and, therefore, simple diffusion through the layers of the cell membrane is not an option
TRUE
What factors affect a drug’s ability to cross a bilayer membrane?
Lipid solubility
Degree of ionization (charge)
Molecular size
Shape of the drug molecule
How does Lipid Solubility affect a drug’s ability to cross a bilayer membrane?
The more lipid soluble the drug the easier it will cross
How does degree of ionization (charge) affect a drug’s ability to cross a bilayer membrane?
- Charged molecules cannot cross (they must used pores/channels)
- Hydrophobic drug molecules can generally pass through easily
- Water hating fat loving
How does molecular size affect a drug’s ability to cross a bilayer membrane?
Small - sized molecules can cross the cell membrane easily
How does shape of the drug molecule affect a drug’s ability to cross a bilayer membrane?
Molecules that can contort to fit through the cell membrane can cross more easily
an extremely selective barrier that separates the circulating blood from the brain extracellular fluid in the CNS
The blood-brain barrier (BBB)
a specialized barrier formed by capillary endothelial cells connected by tight junctions
The blood-brain barrier (BBB)
__________ are necessary to create the BBB
Astrocytes
What Physiologic Barrier allows passage of water, some gases, and lipid soluble molecules by passive diffusion
The blood-brain barrier (BBB)
What Physiologic Barrier allows selective transport of molecules such as glucose and amino acids that are crucial to neural function
The blood-brain barrier (BBB)
What Physiologic Barrier can prevent the entry of potential neurotoxins by way of an active transport (requires energy) mechanism
The blood-brain barrier (BBB)
What Physiologic Barrier prevents passive diffusion of most drugs from systemic to cerebral circulation
The blood-brain barrier (BBB)
an important homeostatic mechanism that protects the inner ear
The blood-labyrinth barrier (BLB)
What Physiologic Barrier Maintains a constant composition of the inner ear fluids and is essential for its function?
The blood-labyrinth barrier (BLB)
What Physiologic Barrier allows for antigens and antibodies to cross both ways
The blood-placental barrier
What Physiologic Barrier is not a strong barrier for drugs as most can cross easily; Non-ionized and lipid-soluble drugs cross most easily
The blood-placental barrier
The blood-placental barrier Small molecules can cross the placental barrier such as & what can it cause ?
Many viruses, including
cytomegalovirus (CMV),
rubella (German measles),
varicella-zoster (chicken pox),
measles,
HIV (AIDS),
Zika, and
poliovirus can cross the placenta
All of these viruses can potentially cause congenital deafness/ hearing loss
what does not typically cross the blood-placental barrier
Bacteria and other protozoa do not ordinarily cross the barrier
what Exceptions can cross the blood-placental barrier
treponema palladium (syphilis) &
toxoplasma gondii (Toxoplasmosis),
- which can cause congenital hearing loss
Disruption of __________ can disrupt ion transport system of the lateral cochlear wall, lead to disturbances of inner ear homeostasis, resulting in functional disruption of the auditory system
The blood-labyrinth barrier (BLB)
True or false
for the blood-labyrinth barrier (BLB) large molecular weight molecules can enter the perilymph in a dose and time dependent manner
FALSE!
SMALL molecular weight molecules can enter the perilymph in a dose and time dependent manner
Several ototoxic drugs and bacteria can cross the __________ and enter the perilymph
The blood-labyrinth barrier (BLB)