1. Chapter 6 Section D: Anatomy
7 October 2011
Chapter 6 Section D: Anatomy

2. 1QQ # 13 for 8:30 class
Which will activate muscarinic acetylcholine receptors?
acetylcholine
nicotine
muscarine
curare
atropine.
Nicotinic acetylcholine receptors
Are metabotropic receptors.
Can be activated with nicotine.
Can be activated with acetylcholine.
Can be blocked with muscarine.
Can be activated with atropine.

3. 1QQ # 14 for 8:30 class Pain and temperature information
Is carried in the spinothalamic tract
Is carried in the dorsal column/medial lemniscal tract
Crosses (decussates) in the spinal cord
Is relayed to the somatosensory cortex via 3rd order neurons in the thalamus
Is carried in the anterolateral tract.
Which are true of touch and proprioception pathways?
Second order neurons are located in the dorsal column nuclei
Axons of first order neurons travel in the spinothalamic tract
Axons of first order neurons decussate (cross the midline) in the spinal cord
Axons of second order neurons travel in the medial lemniscus.
Axons of first order neurons ascend in the dorsal columns and synapse onto second order neurons in the dorsal column nuclei.

4. 1QQ # 13 for 9:30 class
Which will block muscarinic acetylcholine receptors?
acetylcholine
nicotine
muscarine
curare
atropine.
Muscarinic acetylcholine receptors
Are metabotropic receptors
Can be activated with nicotine
Can be activated with acetylcholine
Can be blocked with muscarine
Can be activated with atropine.

5. 1QQ # 14 for 9:30 class Pain and temperature information
Is carried in the anterolateral tract
Is carried in the dorsal column/medial lemniscal tract
Crosses (decussates) in the medulla
Is relayed to the somatosensory cortex via 3rd order neurons in the thalamus
Is carried in the spinothalamic tract.
Which are true of touch and proprioception pathways?
First order neurons are located in the dorsal column nuclei
Axons of first order neurons travel in the spinothalamic tract
Axons of first order neurons decussate (cross the midline) in the spinal cord
Axons of second order neurons travel in the medial lemniscus.
Axons of first order neurons ascend in the dorsal columns and synapse onto second order neurons in the dorsal column nuclei.

6. Types of Ligand-Gated Receptors
= ACH = Acetylcholine
Inotropic receptor
Metabotropic receptor
Agonist = Nicotine
Agonist = Muscarine
Antagonist = Curare
Antagonist = Atropine
Types of Acetylcholine Receptors so named for agonist:
Nicotinic AChR and Muscarinic AChR

7. S 2
Pharmacological agents intended to act in brain must be able to cross blood-brain barrier.
Treatments for Parkinsonism: a) tablets of L-Dopa (which crosses the BBB) unlike Dopamine (which would have widespread effects) b) electrical stimulation c) neuronal transplants (self, fetal, stem cell, pig) NIH Stem Cell Information
Who Cares?
Parkinsons Disease

8. 12 pairs of cranial nerves 31 pairs of spinal nerves
Touch, pain, temperature, proprioception
Vessel stretch,
O2, CO2, etc.
Vision, taste, smell, hearing, equilibrium
12 pairs of cranial nerves 31 pairs of spinal nerves
Skeletal Muscle
Smooth muscle Cardiac muscle Glands
Tracts, pathways, commissures
Nuclei
Control of digestive functions in quadraplegics via enteric nervous system.
Nerves & Ganglia

9. S 4
Figure 6.38

10. S 5
Figure 6.39
Components of gray matter
Amygdala & Hippocampus

11. S 6
How do we know the functions of various brain regions?
Analogy: experiments to discover the function of a battery in a car.
a) Correlations of deficits of stroke victims with brain regions affected.
b) Selective ablations.
c) Selective electrical and chemical microstimulation
i) Dr. Hettes’s experiments on rats
ii) Neurologist Wilder Penfield & Epilepsy

12. S 7

13. S 8
Homunculus = representation of body parts

14. S 9
Dorsal roots = sensory (afferent)
Ventral roots = motor (efferent, both somatic and autonomic)
Gray matter regions of brain and spinal cord
“Pinched nerves” and bulging discs
Ascending and descending axonal tracts in white matter not anatomically delineated.
Atlanta-Boston flight
Origin-Destination
Naming of white matter tracts…..

15. S 10
Explanation for Cervical and lumbar enlargements of spinal cord.
Spinal nerves named for vertebral level.
Using patient’s localization of symptoms with knowledge of dermatomes to determine which spinal nerve is affected by damage.
Epidural injections into region of cauda equina of Lidocaine-like agents to block action potentials in sensory and motor axons without risk of damage to spinal cord. 8 12 5 5 1