Week 3: The Meninges Flashcards
what are the meninges ?
the meninges are 3 layers of membrane that cover and protect the brain and spinal cord.
what is the outermost layer of the meninges ?
the outermost layer of the meninges is the dura mater. it is a thick strong membrane made up of dense irregular connective tissue. it provides protection to the brain and spinal cord.
what is the middle layer of the meninges ?
it is called the arachnoid mater. it is much thinner and is avascular. it has a loose web-like arrangement of collagen and elastic fibers.
what is the innermost layer of the meninges ?
pia mater. it is made up of squamous/cuboidal epithelium and is highly vascularized. it adheres closely to the surface of the brain and spinal cord.
what is the space between the dura mater and arachnoid mater ?
it is called the subarachnoid space. it is filled with cerebrospinal fluid that cushions and protects the brain and spinal cord.
what is the epidural space ?
the space between the dura mater and vertebral bone in the spinal column. it contains fat and blood vessels and is a site for epidural anesthesia during labor.
what is a difference between the spinal and cranial meninges ?
- the cranial meninges have no epidural space.
- there are two layers of dura mater in the cranial meninges called the periosteal layer and meningeal layer.
what are the differences between the periosteal layer and meningeal layer ?
the periosteal layer is the outer layer of the
dura mater that is attached to the skull. the meningeal layer is the inner layer of the dura mater that is attached to the arachnoid mater.
what happens when the dura mater layers separate ?
usually the two layers are attached together but sometimes they split up and create a cavity called a dural venous sinus.
what are dural venous sinuses?
they form when the two layers of the dura mater separate and they are endothelial lined venous channels so they’re carrying blood.
the function is to drain venous blood from the blood and send it through the internal jugular vein.
what is the superior sagittal sinus ?
the superior sagittal sinus is a dural venous sinus that is located in the dura mater along the midline of the brain in the falx cerebri. it collects deoxygenated blood from the brain and drains it into the internal jugular vein.
distinguish between the CNS and the PNS. give two differences and one similarity!
CNS: composed of the brain and spinal cord.
the CNS processes and integrates information. it acts as the main control center of the body.
PNS: composed of nerves and sensory and motor neurons.
the PNS transmits signals between the CNS and the rest of the body.
Similarity: both the CNS and PNS are essential parts of the nervous system, and they work together to regulate bodily functions.
somatic nervous system vs autonomic nervous system. give two differences and one similarity!
SNS: voluntary control. Affects skeletal muscles. Ex: walking
ANS: involuntary control. Affects smooth muscle, cardiac muscle, and glands. Ex: digestion.
Ans can be split into sympathetic nervous system: fight or flight. and parasympathetic nervous system: rest and digest. and the enteric nervous system which is responsible for controlling the gastrointestinal system.
Similarity: both the somatic nervous system and autonomic nervous system are part of the peripheral nervous system.
