Cranial Nerves 9-12 and blood brain barrier

what is CN 9? is it motor, sensory, or both? what does it feel/control?

glossopharyngeal nerve. both. provides sensation to the posterior 1/3rd of the tongue. controls muscles involved in swallowing and secretion of saliva

what is CN 10? is it motor, sensory, or both? what does it feel/control?

vagus nerve (CRITICAL for speech). both.

sensory responsibilities: provides sensation to eh pharynx and larynx, conveys sensory info from the thoracic and abdominal organs

motor responsibilities: controls muscles of the pharynx and larynx involved in speaking and swallowing

parasympathetic: regulates heart rate, digestive processes, and respiratory rate

what is CN 11? is it motor, sensory, or both? what does it feel/control? (4)

spinal accessory nerve. motor. controls 4 things:

• neck and shoulder movements

• soft palate, larynx, pharynx movements

• indirect impact on breathing

• overall muscle coordination and balance

what is CN 12? is it motor, sensory, or both? what does it feel/control?

hypoglossal nerve. motor. controls tongue muscle, necessary for speaking, swallowing, and manipulating food

what is the blood brain barrier? what are its functions?

a critical component of the brain’s defense system. protects the brain from toxins/pathogens, ensures that water and oxygen can pass through (selective permeability)

what are the 3 main components of the blood brain barrier? describe them

1. endothelial cells: line the interior of the vessels. connected by tight junctions

2. pericytes: encircle the endothelial cells, providing structural support

3. astrocytic end-feet: cover the outide of the blood vessel, interacting with the endothelial cells (permeability)

label

1: endothelial cell

2: pericyte

3: astrocytic end feet