BRAIN AND CRANIAL NERVES

Question 1

Blood brain barrier (what is it?)

Answer 1

-selectively permeable membrane
-between blood and the cranial nervous system

Question 2

Blood brain barrier (how is it formed ?)

Answer 2

-formed from special capillaries
-contain tight junctions
-thickened capillary wall
-wrapped with astrocytes

Question 3

Blood brain barrier (advantages)

Answer 3

-restricts molecules that can flow into the brain
-regulates what substances can pass
-prevents exposure to harmful substances

Question 4

Blood brain barrier (disadvantages)

Answer 4

-molecules (ex. glucose) need to be actively transported across the BBB
-if a brain infection does occur, antibiotics have difficulty crossing the BBB into the brain tissues and reaching therapeutic levels

Question 5

Cerebral Spinal Fluid (what is it?)

Answer 5

-clear colorless fluid
-surrounds the brain and spinal cord
-circulates through the internal cavities and spinal cord
-CSF circulates in the central canal of the spinal cord and the subarachnoid space
-CSF produced in ventricles and moves through cerebral aqueduct, then central canal and sub-arachnoid space

Question 6

Cerebral Spinal Fluid (main functions)

Answer 6

1. Protection: in the form of shock
   absorption
2. Homeostatic function:
   maintaining pH, which is
   important for protein
   functioning
3. Circulation: transports
   nutrients and removes waste
4. Buoyancy: brain floats

Question 7

Hydrocephalus

Answer 7

-failure in the CSF to drain properly
-results in the buildup of CSF and causing pressure on the brain
-can occur from congenital abnormalities, head injury, meningitis, and episodes of bleeding into the brain

Question 8

Brain stem

Answer 8

-medulla oblongata
-pons
-midbrain

Question 9

Medulla oblongata

Answer 9

-Cardiovascular center: Controls rate and force of heartbeat and diameter of blood vessels
-Medullary respiratory center: Controls the rate and rhythm of breathing, coughing sneezing, salivation, swallowing, gagging, and vomiting relaxes

Question 10

Pons

Answer 10

-controls breathing
-acts as a relay center of motor control

Question 11

Midbrain

Answer 11

-visual reflexes
-auditory pathways
-startle reflex
-subconscious muscle activities

Question 12

Cerebellum

Answer 12

-compares intended movements with what is happening with skeletal muscles
-regulates posture, equilibrium and balance

Question 13

Diencephalon

Answer 13

-thalamus
-hypothalamus

Question 14

Thalamus

Answer 14

-relays sensory impulses to the cerebral cortex

Question 15

Hypothalamus

Answer 15

-controls and integrates the autonomic nervous system
-coordinates between nervous and endocrine systems
-produces hormones, controls body temperature, regulates hunger/thirst, assists with internal circadian clock

Question 16

Cerebrum

Answer 16

-two hemispheres
-location of the conscious thought and origin of complex intellectual functions
-Brodmann’s areas: Numbered regions of the cerebral cortex that have “mapped” to specific cognitive functions
-Sensory areas: Perception of sensory information
-Motor areas: Voluntary movements
-Association areas: Memory, personality, intelligence
-Corpus callosum: thick band of axons, connects corresponding regions of the tow hemispheres
-Lobes according to bones:
-Parietal
-Temporal
-Occipital
-Frontal

Question 17

Limbic system

Answer 17

-“emotional brain”
-functional system that is composed of regions from the cerebrum and diencephalon
-primary role in pain, pleasure, docility, affection, anger and memory