Case 2

Question 1

What are the four curvatures of the spine?

Answer 1

2 primary concave, 2 secondary convex anteriorly, the primary develop in the fetus, of the secondary the cervical curvature occurs with holding of the head ad the lumber develops during weight bearing in walking

Question 2

What are the 3 most common abnormal curvatures?

Answer 2

Kyphosis, Lordosis ad Scoliosis

Question 3

What is Kyphosis ad what causes it?

Answer 3

Exaggerated curvature of upper thoracic column. It is caused by bad posture, nutritional deficiencies or abnormal development of the spine.

Question 4

What is Lordosis and what causes it?

Answer 4

Exaggerated convex curvature of lumbar spine. Caused by tight low back muscles, pregnancy or excessive visceral fat.

Question 5

What is Scoliosis ad what causes it?

Answer 5

Abnormal lateral curvature (S-shaped spine). Cause can be congenital, due to abnormalities at birth or idiopathic.

Question 6

Outline the characteristics of a cervical vertebrae

Answer 6

Small, rectangular body, large triangular foramen, bifid spinous process, smallest vertebrae with greatest rage of movement.

Question 7

Outline the characteristics of a thoracic vertebrae.

Answer 7

Heart-shaped, large bodies, circular vertebral foramen, long, inferiorly sloping spinous process, long strong spinous process.

Question 8

Outline the characteristics of lumbar vertebrae

Answer 8

Massive, kidney shaped body, triangular foramen, short, broad spinous process.

Question 9

After notocord development, what three solid rods of cells develop from the mesoderm?

Answer 9

Paraxial mesoderm, intermediate mesoderm ad lateral plate mesoderm. They run parallel to the notocord.

Question 10

Which rod of mesoderm forms the somites?

Answer 10

Paraxial mesoderm.

Question 11

What are the three regions of somites, and what does each region develop into?

Answer 11

Portion nearest notocord and neural tube differentiates intosclertome which will form bone, cartilage, tendons, ligamnets, annulus fibrosus, connective tissue and meninges. The portion of somite nearest ectoderm differentiates into dermatome and becomes skin. The remaining portion differentiates into myotome which will go on to form deep back and neck muscles.

Question 12

How do IV discs form from these?

Answer 12

The sclerotomal portion of each somite differentiates into two regions, anterior and posterior, some of the anterior cells migrate cranially to become the basis of IV discs. As the veretabral bodies, the notocord becomes extremely small in the vertebrae and larger in the IV discs, leading to it gelatinous centre, the nucleus pulposus. This is surrounded by circularly arranged fibers later that constitue the annulus fibrosus.

Question 13

What are unencapsulated nerve endings and what do they mediate? Give an example.

Answer 13

Most abundant type of sensory nerve ending, they mediate painful and thermal sensations eg. Merkel endings.

Question 14

What are encapsulated nerve endings and give an example?

Answer 14

Nerve endings surrounded by a stuctural specialisation of non-neural tissue, the nerve and surrounding tissue are commenly referred to as a corpuscles eg. Meissner’s Corpuscles.

Question 15

Noxious stimulation causes cells damage which causes the release of which chemical mediators?

Answer 15

K+, ATP and ADP, Bradykinin which is formed by circulating globulins with proteolytic enzymes, Histamine and Leukotriens from mast cells, Serotonin from platelts, Lactic acid due to ischemia and Prostaglandins.

Question 16

Where does the spinomesencephalic tract project to?

Answer 16

Periaqueductal grey (PAG) and the superior colliculus.

Question 17

What effects do projections to the PAG in the spinomesencephalic tract cause?

Answer 17

Sent to the posterior horn, they modulate pain at both NS and WDR neurons.

Question 18

What do projections from the superior colliculaus through the spinomesencephalic tract cause?

Answer 18

Influence the movement of our eyes, directing our gaze to the site of injury.

Question 19

Where does the spinoparabracial tract project to and what does it cause?

Answer 19

Parabracial nucleus, that then project to the hypothalamus and amygdala, these connections activate the pituitary-adrenal axis stress response, affects appetite and sleep and mediates fear learning.

Question 20

What is encephalin and what are its two forms?

Answer 20

Penapeptide involved in regulating nocicption in the body. From the two forms one contains leucine (Leu-encephalin) and another contains methionine (Met-encephalin).

Question 21

What is the definition of drug dependency?

Answer 21

Development of withdrawl symptoms when the substance is discontinued.

Question 22

How does drug dependency develop?

Answer 22

Drugs increase the dopamine in the mesolimbic pathway dopaminergic system. This is a reward pathway that begins in the ventral tegmental area of the midbrain and connects to the nucleus accumbens. Increasing the level of dopamine in the NA mediates positive reinforcment of the drug.

Question 23

How does tolerance occur?

Answer 23

receptors become less response to the drug stimulation, so more is needed to create the same effect.

Question 24

What is the criteria for diagnosis addiction?

Answer 24

Of a list of statements, if the patient meets 2-3 they are considered to have mild addiction, 4-5 moderate and 6-7 severe. Statements include: Continuing to use despite negative personal consequences, tolerance, withdrawl, stopping or reducing important social, occupational or recreational activities. ect.