Lecture 9 (EXAM 2)

Question 1

What are antioxidant systems other than Superoxide dismutase?

Answer 1

-Vitamin C, Vitamin E
-Glutathione GSH (Glutamate, Cysten, Glycin) -> Cystein has an SH group providing antioxidant capacity (free radical neutralizer)

Question 2

How does Glutathione provide protection from free radicals?

Answer 2

It takes up free radicals (O*) and will be oxidized and forms a dimer with another Glutathione
-> GSH + GSH -» GSSH (dimer)

the dimer can be broken up by receiving an electron from NADPH
GSSH -> GSH + GSH

Question 3

How can GSSH be recycled?

Answer 3

-By the reduction to GSH with electrons provided by NADPH
-GSH can neutralize free radicals again

Question 4

Where is NADPH coming from?

Answer 4

1. Glucose is converted into Glucose-6-P when entering the cell
2. G6P-Dehydrogenase takes off an H atom from G6P and reduces NADP+ to NADPH

Question 5

What is the role of NADPH in biochemical reactions?

Answer 5

It is a reducing equivalent and donors electrons for many biochemical reactions

Question 6

Which gene abnormality affects the amount of NADPH?

Answer 6

-genetic variation of G6P-Dehydrogenase
-millions of people affected
-all variations have reduced function
-people living on the equatorial area often affected

Question 7

Which disease is associated with a dysfunctional form of G6P-DH in people living in the equatorial area?

Answer 7

Malaria

Question 8

Why are G6P-DH deficiencies harmful to patients?

Answer 8

-Because people with reduced function of G6P-DH will produce less NADPH -> lowering their ability to control oxidative stress

-a number of drugs can cause oxidative stress

Question 9

What is the first symptom in patients suffering from increased oxidative stress and G6P-DH deficiency?

Answer 9

Hemolytic anemia

Question 10

Which NT on the pre-ganglionic neuron and which receptor on the post-ganglionic neuron is involved in signal transduction?

Answer 10

ACh and nicotinic receptor

Question 11

Which NT is released for the Parasympathetic system and which receptor does it bind to at the organ?

Answer 11

ACh binding to the muscarinic receptor

Question 12

What would be the effect of ACh binding to nicotinic receptors?

Answer 12

ALWAYS stimulatory

-nicotinic receptors present in all ganglia, adrenal medulla, and on skeletal muscles

Question 13

Which NT is released for the Sympathetic system and which receptor does it bind to at the organ?

Answer 13

NE binding to alpha or ß-receptors

Question 14

Length of pre & post-ganglia

Answer 14

Parasympathetic: long Pre-ganglia - short Post-ganglia

Sympathetic: short Pre-ganglia - long Post-ganglia

Question 15

What are the exception of NT release in the sympathetic system?

Answer 15

-Sweat glands -> ACh to muscarinic receptors
-Renal vascular smooth muscle -> Dopamin to Dopamin receptors
-ACh on nicotinic receptors (ganglion) and Epinephrine and NE release into the circulation

Question 16

What is special about somatic (skeletal muscle) stimulation?

Answer 16

-it has no ganglia

-ACh to nicotinic receptor

Question 17

What happens with the nervous system in a Fight or Flight situation?

Answer 17

hair stands up
-sweating (ACh - muscarinic receptor)
-dilation of the pupil (to receive more light), lens flattens for distance vision
-airways open up
-saliva production stops
-ingestion stops
-heart increases, the force of attraction increases
-liver function increased (Gluconeogenesis, fat as source)
-bladder emptying blocked
-vasoconstriction in areas that are not important in fight situation (skin, intestine) -> blood flow to muscles

Question 18

How can organs be connected to Parasympathetic and Sympathetic nerves and still have different effects?

Answer 18

Because depending on the situation FIGHT or FLIGHT/FEED & BREED one system is stimulated more

Question 19

How do parasympathetic nerves cause discrete responses?

Answer 19

-parasympathetic nerves don’t merge in ganglia, they are directed separately to the organs
f.e. FEED & BREED: watery mouth - but no constriction of pupils

Question 20

How do sympathetic nerves cause general responses?

Answer 20

-sympathetic nerves merge in ganglia, so when activated they stimulate multiple organs
f.e. FIGHT or FLIGHT: dry mouth + dilation of pupils

Question 21

Where do different nerves of the parasympathetic originate from?

Answer 21

Medulla:
cranial nerve 3: Eye (pupils)
cranial nerve 7: Salivary glands, nasal mucosa
cranial nerve 9: Salivary glands, nasal mucosa
cranial nerve 10 (Vagus nerve): Lungs, heart, intestine, stomach, kidney, liver, gallbladder, and more

Sacral spine: Intestine, Bladder, Genitals

Question 22

Where do different nerves of the sympathetic originate from?

Answer 22

-Thoracic spine
-Lumbar spine

Question 23

What is the autonomic tone?

Answer 23

baseline input (constitutive activity) on the organs from both the parasympathetic and sympathetic systems

Question 24

What would happen to the heart rate if the parasympathetic Vagus nerve was damaged?

Answer 24

-The heart rate would go up because the heart is also stimulated by the sympathetic NS

-the Parasympathetic nerve decreases heart rate, so when cutting it off only sympathetic stimulation would occur

Question 25

What is the effect of ACh binding on muscarinic receptors?

Answer 25

-can be either inhibitory or excitatory -> depending on the receptor (M1, M2, M3, M4, M5) -> slow the heart, but stimulates the bladder (both PARAYSMPATHETIC) -muscarinic receptors found on all organs

Question 26

What is the effect of NE binding on adrenergic receptors?

Answer 26

-α1-receptors are generally stimulatory -α2-receptors are generally inhibitory -ß-receptors are generally inhibitory (ß1, ß2, ß3) Exception ß-receptors of the heart are stimulatory