S2.B1 Meninges

As a result, CSF is usually cloudy with many white blood cells, increased protein, and bacteria.

Dura mater is also called the pachymeninx. The arachnoid and pia mater are collectively called the leptomeninges

It may also have some sensation through the vagus nerve.
*Irritation of the dura here will have referred pain to the back of the head.

A subdural hematoma is between the dura and arachnoid planes. More specifically, it is in the dural border layer.

The arterial supply to the cranial dura mater, particularly from the middle meningeal artery, runs between the periosteum of the skull and the periosteal layer of the dura mater. This space is known as the epidural space (potential space in the cranium). Damage to these arteries, especially in trauma, can lead to epidural hematomas, which are medical emergencies. So, the statement is true.

The correct answer is meninges. The meninges are connective tissue membranes that surround and protect the central nervous system, which includes the brain and spinal cord. These membranes consist of three layers: the dura mater, arachnoid mater, and pia mater. The meninges provide a barrier against infection and physical damage, as well as help to regulate the circulation of cerebrospinal fluid.

The falx cerebri lies in the longitudinal fissure and separates the hemispheres.
It is the tentorium cerebelli that lies in the transverse fissure but it separates the cerebrum from the cerebellum.

Meningeal septa are thin partitions that divide the cranial cavity into compartments. These septa help to provide structural support and organization within the cranial cavity. They separate different regions of the brain and help to prevent the spread of infection or injury from one area to another. Therefore, meningeal septa are most responsible for forming compartments in the cranial cavity.

The brain is insensitive to pain, but the dural coverings are sensitive.

The correct answer lists the layers of the meninges in the correct order from outside to inside. The meninges are the protective membranes that surround the brain and spinal cord. Starting from the outside, the order is as follows: Skull, periosteal dura, meningeal dura, dural border cells, arachnoid barrier cells, subarachnoid space, and pia mater. This order represents the layers of the meninges, with the pia mater being the innermost layer that directly covers the brain and spinal cord.

they are venous structures

The periosteal layer of dura is attached to the skull, but not to the vertebral column.

Kernig sign is where the thigh is lifted at a 90 degree angle, an attempt is made to straighten the leg. Inability to straighten, due to tight hamstrings is an indication of meningitis.
Brudzinksi sign is where the head it pulled upward and the knees bend in reaction to stretching the dura.

The infratentorial dura is innervated by cervical spinal nerves 2 and 3. As such, irritation of this dura will refer pain to the back of the neck.

Viral meningitis can be caused by a variety of viral agents and is usually seen in younger patients. Few antiviral agents are effective in treatment, therefore treatment in mild cases is generally only supportive, with conditions improving in 1-2 weeks.

It is the extension of the spinal meninges after the end of the spinal cord, usually around L1-L2. It contains the cauda equina and it is the space commonly accessed in spinal taps

The pia mater forms the filum terminale internum, while the dura has a specialized projection called the filum terminale externum

The irritation of nerves in the dura can produce referred pain (usually a headache) that appears to originate in the area of the afferent nerve innervation.
In this case, where dura above the tentorium cerebelli is innervated by the trigeminal nerve, a headache in this region will be referred to the face.

During the first month of development, the meninges begin to form. By the end of the first trimester, which is also the end of the first month, they have already developed into three layers, which is the adult pattern. Therefore, the correct answer is 1st, 1st.

The arachnoid villi are specializations of the dura arachnoid interface in dural sinuses that allow the drainage of CSF into the venous system. It is essential in order to maintain intracranial pressure.

The arachnoid mater has two primary parts, the arachnoid barrier layer and the arachnoid trabeculae. The arachnoid trabeculae play a crucial role in suspending the brain in the subarachnoid space. Additionally, the trabeculae help to reduce the weight of the brain by about 97%.

The ectomeninx around the brain stays attached to the periosteal connective tissue layer. But in the spinal cord, it is initially continuous with the vertebral periosteum during development but later separates forming epidural space

The dura mater is divided into periosteal, meningeal, and border cell portions. The most distinct boundary is between dural border cells and meningeal dura.
The periosteal and meningeal layers contain a large amount of collagen and are very strong.
*Meanwhile, the border cell layer lacks dense CT, forming weakness between the arachnoid and dura...this can allow for blood to flow into these layers creating a subdural hematoma.

Is where the ectoderm fails to completely dissociate from neuroectoderm, leaving an epithelium lined channel to the surface of the skin

consist of areas in which the meningeal portion of the dura folds inward to separate the cranial cavity into compartments.
Although the diaphragma sella is a dural septa, it is the smallest septum forming the roof of the hypophyseal fossa encircling the infundibulum.

They may invade the adjacent skull but rarely penetrate brain tissue. Neurological signs are generally due to compression or edema.