Micro Bio Exam 5 Ch 24

Central Nervous System (CNS)

Central Nervous System (CNS)

Controls and coordinates everything and includes brain and spinal cord

Peripheral nervous system (PNS)

Collects data from the body and includes spinal nerves and neurons

Types of neurons

Sensory neurons and Motor neurons

Sensory neurons

Send signals from the sensors in the periphery to CNS

Motor Neurons

Send signals from the CNS to the periphery

Tetanus (Clostridium tetani) (anaerobe)

The painful disease causes intense muscle contraction and Tetanospasmin toxin blocks  the release of GABA, an inhibitory transmitter.

Naegleria fowleri (amoeba)

Infected brain tissue and causes acute and usually lethal CNS infection

Found in freshwater lakes, and very deadly.

Botulism (Clostridium botulinum)

Foodborne pathogens and commonly associated with vegetables and hone due to spores being in soil. Paralysis is due to a toxin binding to motor neurons and blocking acetylcholine release. The bacteria do not survive well in highly acidic environments

Poliomyelitis

Very contagious virus transmitted by fecal-oral route or directly from person to person. Most infected patients are asymptomatic and Only 1% of symptomatic patients develop paralysis. Vaccine efforts have come close to eradicating the disease

Rabies

A zoonotic disease that accumulations of large numbers of viruses in intracellular inclusions (Negri bodies)

Types of meningitis

Bacterial, viral. Bacteria are more lethal. Have to look at the cerebral spinal fluid and viral is clear and bacterial is cloudy.

Fungal infections of CNS

Coccidiodial meningitis is caused by species that grow in dry desert soil. Windy conditions easily spread spores and Initially present as pneumonia and weeks or months later can disseminate and cause meningitis

Candida meningitis is the most common fungal infection and can cause abscesses and meningitis

A pathologist detects Negri bodies while examining a brain section taken at autopsy. What was the cause of death?

rabies

What is the correct order of the meninges, beginning from the most outer structures?

dura mater, arachnoid, pia mater

Bacterial encephalitis and meningitis are difficult to treat because

many antibiotics cannot cross the blood-brain barrier.

The part of the nervous system that collects data from the environment is the

Peripheral nervous system

Naegleria fowleri is commonly acquired through

swimming in warm ponds or streams.

Vaccination is available for all the following EXCEPT

botulism

Which of the following is true about myelin sheaths?

They are destroyed in certain disorders such as multiple sclerosis.

Motor neurons send information

from the CNS to the periphery.

Which of the following statements about prions is correct?

Prions can be transmitted via contaminated food.

The three major types of diseases associated with the CNS are all of these EXCEPT

dermatitis.

Neuron Structure