Apologia Advanced Biology Module 8 Lecture 2

Front 1

meninges

Back 1

three specific layers of tissue surround and protect the brain

Front 2

dura mater

Back 2

The meninges layer right beneath the skull
attached to the periosteum of the skull so that they form one layer

Front 3

dural sinuses

Back 3

collect the blood which returns from the brain as well as cerebrospinal fluid

Front 4

arachnoid mater

Back 4

next layer of meninges below the dura mater

Front 5

subdural space

Back 5

The space between the dura mater and the arachnoid mater

Front 6

pia mater

Back 6

last meningeal layer below the arachnoid mater

Front 7

subarachnoid space

Back 7

The space in between the arachnoid layer and the pia mater

Front 8

meningitis

Back 8

This is a potentially life-threatening situation which can be caused by viruses or bacteria. Meningitis is an inflammation of the meninges.

Front 9

median foramen

Back 9

allow the CSF to leave the ventricles and enter the subarachnoid space.

Front 10

arachnoid granulations

Back 10

which dump the CSF into a dural sinus

Front 11

Damage to the dural sinuses can cause bleeding into the subdural space. This is called a “subdural hematoma.” What effect would this condition have on the brain?

Back 11

This would lead to pressure on the brain. If the dural sinuses fill up, the pressure will push on the brain, which can lead to unconsciousness

Front 12

When someone fractures a skull, the meninges can be torn. This can cause CSF to leak out of the nose or the ear. This situation is dangerous not only because it indicates severe damage to the head, but also because it increases the risk of meningitis. Why would leakage of CSF out of the body increase the risk of meningitis?

Back 12

If CSF is getting out, that means bacteria and other pathogens can get in. Since meningitis is caused by bacteria and viruses, this increases the risk of meningitis.

Front 13

lumbar enlargement

Back 13

a region of increased diameter where the nerves of the lower limbs enter and exit the spinal cord

Front 14

conus medullaris

Back 14

Just below the lumbar enlargement, the spinal cord tapers to a conelike structure

Front 15

cauda equina

Back 15

conus medullaris and the many nerves that attach to it because together, they look like a horse's tail.

Front 16

dorsal column

Back 16

column on the back side of the spinal cord

Front 17

lateral column

Back 17

is on the side of the spinal cord

Front 18

ventral column

Back 18

is on the belly side of the spinal cord

Front 19

fasciculi

Back 19

columns are further divided called nerve tracts

Front 20

dorsal horn

Back 20

Axons from the sensory neurons synapse with association neurons

Front 21

ventral horn

Back 21

The cell bodies of the motor neurons

Front 22

lateral horns

Back 22

cell bodies of the autonomic neurons

Front 23

dorsal roots

Back 23

On each side of the spinal cord

Front 24

dorsal roots

function

Back 24

The dorsal root enters the spinal cord at the posterior horn, and it carries afferent signals from the sensory receptors to the spinal cord. Each dorsal root also contains a ganglion, which is made up of the cell bodies of afferent neurons.

Front 25

ventral roots

Back 25

The ventral root leaves the spinal cord at the ventral horn, and it carries efferent action potentials from the spinal cord to the effectors

Front 26

dorsal root ganglia

Back 26

are where these cell bodies are gathered

Front 27

epidural anesthetic

Back 27

anesthetic is injected into epidural space, and it deactivates the spinal nerves so that the afferent pain signals do not reach your brain.

Front 28

epidural space

Back 28

between the vertebral column and the dura mater.

Front 29

Where are the cell bodies of the neurons which make up the ventral root?

Back 29

the cell bodies are in the spinal cord

Front 30

reflex arc

Back 30

the neural pathway that mediates a reflex action

Front 31

When you touch a hot stove, your hand pulls back quickly as a result of the reflex arc. However, when you touch warm water, you do not pull your hand back quickly. Thus, the reflex arc has a decision-making mechanism that interprets the afferent signals and determines whether or not the reflex should be activated. Which neuron in the reflex arc is responsible for this?

Back 31

The association neuron must be responsible for this

Front 32

afferent neuron simply sends the signal into the spinal cord

Back 32

simply sends the signal into the spinal cord

Front 33

efferent neuron

Back 33

sends the signal to the muscle

Front 34

association neuron

Back 34

directs the message

Front 35

motor pathway

Back 35

descending pathways - motor nerves carry signals from the CNS to the muscles

Front 36

sensory pathway

Back 36

ascending pathways, because the action potentials begin in the receptors of the PNS and then travel up the spinal cord to the brain.

Front 37

upper neurons

location & function

Back 37

neurons in the motor cortex

send action potentials down through the midbrain, through the pons, and to the medulla

Front 38

medullary pyramid

location & function

Back 38

medulla

approximately 80% of the axons cross over

Front 39

lower motor neuron

location & function

Back 39

neuron between the spinal cord and muscles

will carry the signals to the neuromuscular junction of the muscle

Front 40

indirect motor pathways

location & function

Back 40

These pathways have more synapses

carry those signals which need a significant amount of regulation.

Front 41

primary neuron

Back 41

where action potentials will be produced in a sensory pathway.

Front 42

secondary neuron

Back 42

neurons between the spinal cord and brain