Occupational Health Exam 3

What is the lungs first line of defense? Describe it and what are the four actions that makes this happen?

1. progressive mechanical filtering through the upper airways (nose, nasopharynx, pharynx, and larynx) and the lower airways.

Four actions:
1. Filtration
2. sedimentation
3. sneezing
4. coughing

What is the second line of defense? Examples?

- fluids that line the airways
-gas exchange structures
- clearance mechanism that physically remove particles from the airway surface

Examples:
-mucociliary epithelial barriers
-macrophages

What is the lungs response to exposure to an environmental agent? ****How does exposure to the same agent but in different forms and concentrations affect the actions?***

-Exogenous agent --> lung reactions --> 1,2,3,4

Where:
1. resolution
2. permanent alteration
3. Scarring
4. Neoplasia

- reactions produced may differ in type and severity

What are the five types of asbestos?

1. Chrysotile
2. Amosite
3. Crocidolite
4. Anthophyllite
5. Tremolite

What are the two forms of asbestos? Which is most often seen?

1. fibrous mineral of two major types
-serpentine: 95%
-amphibole: 5%
2. Hydrated magnesium silicates

Define hepatoxicity.

1. any change from the normal state


2. More specifically any change in
---enzyme: activity/amount
---organelle or membrane: structure/composition


3. Any change in cell:
---ultra structural appearance
--- integrated activity

5. Any change
---bile production
---blood: flow and distribution
----distribution/metabolic interactions with other organs

What are the three major functions that the liver performs?

1. plasma proteins SYNTHESIS AND RELEASE
2. maintenance of carbohydrate, glycolipids, sterile and amino acid HOMEOSTASIS
3. toxic exogenous substances BIOTRANSFORMATIONS

What factors influence toxicity due to dose?

1. route of contact (physiochemical properties)
2. bioavailability
3. Metabolism

What are the four principal effects that developmental toxicants can have an offspring? **** know the graphical representation of the effects observed between an embryo and the other. Draw and label it and know it.***

1. death of the fetus
2. structural malformation
3. altered growth
functional deficiency

idk about the graph

What are the two basic forms of peripheral nerve damage? describe each.

1. Segmental demyelination
2. Axonal degeneration

Segmental demyelination

1. primary destruction of the neural myelin sheath with some sparing of the axon
-Begins at nodes of Ranvier
-slows the nerve conduction
-no muscle denervation but atrophy may occur if long term paralysis occurs
-remyelination begins during recovery
-recovery is rapid in mild to moderate neruopathies

Axonal degeneration

1. Associated with metabolic derangement of the entire neuron and manifested by the degeneration of the distal portion of the nerve fiber
-myelin sheath degeneration may also occur
-Nerve condition rates are normal until condition worsens
-distal muscles show denervation
-recovery may occur by axonal regeneration but is slow and incomplete segmental demyelination may co-exist.

What are the three defined stages of fetal development

1. pre implantation (conception - 17days)

2. embryonic (18-58 days post conception ... organogenesis occurs)

3. fetal (58 days to birth)