SOLUTIONS
- Acetylcholine(Ach)
- Glutamate
- GABA
- Glycine
**These ligands can also act on metabotropic receptors Correct
Answers What are the principle ligands that can act on
ionotropic receptors? (4)
- Amount of light that enters the eye (Constriction = less light
enters)
- Focus (Constriction = better focus)
- Depth of view (Constriction = greater depth of view) Correct
Answers What functions does the pupil resolve? (3)
- cAMP
- cGMP
- InP3 Correct Answers What are the types of 2nd messengers
that can be stimulated by metabotropic receptors
- Controls bilateral coordination of limbs when different motions
are done on each side
- Processes internal 'volitional' signals that drive movements
Correct Answers What is the function of the supplementary
motor area? (2)
- Dura mater (very tough membrane, sac containing the brain
and the spinal cord)
,- Arachnoid membrane (much more delicate tissue)
- Pia mater (lies right on top of the brain; tethered to Arachnoid
by Arachnoid 'Trabeculae') Correct Answers What are the three
sections of the meninges?
- Hypothalamus (Communicates with blood stream)
- Pituitary Gland (Releases/Senses hormones in blood)
- Circumventricular organs (Around third ventricle), so neurons
can sense specific chemical concentrations
- Medulla Oblongata - Vomiting centre monitors for toxic
substances Correct Answers What are some areas where the
blood-brain barrier are broken? (4)
- Metencephalon (pons, cerebellum)
- Myelencephalon (medulla oblongata) Correct Answers What
are the two segments of the hindbrain which form at 6 weeks
development?
- On top of tongue (Mainly)
- Soft palate
- Epiglottis
- Upper esophagus Correct Answers Where are tastebuds
found? (4)
- Physical protection - buoyancy reduces brain weight > less
pressure on nerves and blood vessels
,- Waste removal
- Regulation of the ECF environment for neurons Correct
Answers 0What are the functions of CSF? (3)
- Temperature regulation
- Regulation of feeding
- Plasma osmolality
- Sexual response
- Stress response Correct Answers List five functions of the
hypothalamus
- To control the ionic composition of the extracellular fluid
around neurons
- To remove neurotransmitters floating in the CSF Correct
Answers What is the function of the blood-brain barrier? (2)
- Water, CO2 and O2, and lipid -soluble free forms of steroid
hormones are freely penetrable
- GLUT1 transporter for glucose
- Transporters for thyroid hormones
- Multidrug non-specific transporter (P- glycoprotein) transports
drugs and peptides back into the blood from the brain Correct
Answers What is the BBB selective for and how? (4)
, -10mV Correct Answers What is the potential difference across
the cell membrane between sodium and potassium ions caused
by the sodium-potassium pump?
-55mV (Depolarization required) Correct Answers What is the
minimum threshold potential required to open a voltage gated
sodium channel?
-90 mV (This would be the membrane potential if ONLY K+
were involved) Correct Answers What is the equilibrium
potential of potassium ions?
-Deletion of the SRY gene (Male differentiation is avoided
completely)
-Defective gene for 5 alpha-reductase (No external male organ
development)
- Complete androgen insensitivity (androgen receptors not
functional - so testosterone and DHT are non-functional,
produces an infertile phenotypic female) Correct Answers If an
XY genotypic fetus is phenotypically a female, what could be a
possible cause? (3)
-Increased plasma glucose (Stimulation)
-Increased plasma amino acids (Stimulation)
-GLP-1/GI hormones secreted by the intestine (Stimulation -
anticipatory feedforward effect)
-Parasympathetic system (Stimulation - During and following a
meal)
-Sympathetic system (Inhibition - stress inhibits secretion to
provide extra fuel) Correct Answers What stimulates/inhibits
insulin secretion from the pancreas? (5)