Week 3

A branching network of vessels or nerves on the spinal cord

It is the end of the spinal cord

It is a thread like structure that the spinal nerves emerge from the spinal cord and exit the vertebral column

The Filum terminale is a thread-like structure made of fibrous tissue that extends from the tip of the conus medullaris to the tailbone. Its function is to provide longitudinal support and stabilization to the spinal cord.

They are cervical, thoracic, lumbar, sacral and coccyx

Cervical 3-5

The first 7 cervical spinal nerves lie above the corresponding vertebrae

All other spinal nerves lie below the corresponding vertebrae

They are composed of cell bodies

It processess sensory information

It processes motor information

It processes autonomic information

It is made up of travelling axons

The cranial nerves 3 to 12

Cranial nerves (10 pairs) enter/exit the CNS via the brainstem

Spinal nerves (31) contain sensory and motor axons from a single spinal segment and enter/exit the CNS via the spinal cord

The dorsal (afferent) root contains sensory axons responsible for bringing information into the spinal cord

he ventral (efferent) root contains motor axons (efferent) that carry information from the spinal cord to the body segments, enabling motor functions

It is a afferent axon

It is a efferent axon

They are sensory axons

They are motor neuron

They are mixed being both motor and sensory neurons

The dorsal ramus supplies muscles of the back and the overlying skin

The ventral ramus supplies muscles of the trunk and limbs, as well as the overlying skin

They are the area of skin innvervated by a single spinal nerve

They are the group of muscles innervated by a single spinal nerve

Paraplegia refers to paralysis of the lower limbs resulting from an injury to the thoracic and lumbar cord

The most common level of injury associated with paraplegia is T12/L1

Quadriplegia, or tetraplegia, is characterized by paralysis of both the upper and lower limbs due to an injury to the cervical cord

The most common level of injury associated with quadriplegia (tetraplegia) is C4-5

Paresis refers to partial loss of voluntary movement and can result in partial loss of all forms of sensation

Analgesia refers to the inability to feel pain or reduced pain sensitivity

Paralysis is the loss of ability to move voluntarily due to the inability to contract muscles

Paresis involves partial loss of voluntary movement, whereas paralysis entails complete loss of voluntary muscle control

A segmental lesion affects the function of a specific spinal cord segment. These lesions interfere with neural function only at the level of the lesion

A vertical tract lesion involves the interruption of ascending and descending information pathways in the spinal cord. Such lesions result in a loss of function below the level of the lesion

A segmental nerve lesion at the horn, root, or spinal nerve level can result in altered or lost sensation in a dermatome at that level, decreased or lost muscle power in a myotome at that level, and decreased or lost stretch reflex

A vertical tract lesion can lead to altered or lost sensation below the level of the lesion, motor tract signs including decreased or loss of muscle power, spasticity, and muscle hypertonia, as well as altered or lost control of blood pressure, bladder and bowel control, and thermoregulation

Vertical tract lesions to the spinal cord affect the motor pathways of the spinal cord, which include both sensory and motor functions

Segmental lesions to the spinal cord affect the corresponding dermatome and myotome levels of the body

They are either complete injury or incomplete injury

An incomplete injury exhibits variable levels of sensation and/or movement in one limb compared to the other

A complete injury entails no sensation and no voluntary movement below the spinal cord lesion

They are three protective connective tissue lauyers that surround the brain, brainstem and spinal cord

Cover and protect the CNS, protect blood vessels on the surface of the CNS, form dural venous sinuses and cerebrospinal fluid is located in the subarachnoid space

DAP -> Dura mater, arachnoid mater and pia mater

The dura mater is a two-layered sheet of fibrous connective tissue

The dura mater forms dural venous sinuses

The dura mater forms septa within the skull

The arachnoid mater is a layer of the meninges that serves as a loose weblike covering of the brain

Arachnoid granulations are small projections found in the arachnoid mater. They allow cerebrospinal fluid (CSF) to re-enter the circulation via dural venous sinuses

The arachnoid mater is superficial to the subarachnoid space

he pia mater is a delicate layer that clings closely to brain tissue and provides a dense, rich blood supply to the underlying neural tissue

It is found in the cerebral hemispheres

It is found in the between the rights and left thalamus

It is found in the posterior to pons and medulla

The vertebral artery leads blood to a specific part of the brain

The basilar artery and internal carotid arteries link up on the inferior surface of the brain to form the Circle of Willis

A ring of vessels connecting the anterior and posterior circulations of the brain

They are the anterior cerebral, middle cerebral, posterior cerebral

Anterior cerebral artery, middle cerebral artery and posterior cerebral artery

Should have anterior, middle and posterior cerebral artery

The anterior cerebral artery supplies the medial cortical surfaces of the frontal and parietal lobes, particularly the prefrontal cortex, and the lower limb region

Signs of involvement with the anterior cerebral artery include paralysis of the contralateral lower limb, sensory loss in the contralateral lower limb, mental impairments, and urinary incontinence

The middle cerebral artery supplies the entire lateral cortical surface of the frontal, parietal, and temporal lobes

The middle cerebral artery supplies the head, upper limb, and thoracic area

The middle cerebral artery supports hearing and language areas, as well as the frontal cortex, basal ganglia, and internal capsule

he posterior cerebral artery supplies the occipital lobe and the inferior cortical surfaces of the temporal and parietal lobes

The terminal branches of the posterior cerebral artery anastomose with branches of the middle cerebral artery (MCA) at the inferior margin of the occipital, temporal, and parietal lobes

The posterior cerebral artery primarily supplies the visual area and the subthalamic nuclei

Signs of involvement with the posterior cerebral artery include contralateral homonymous hemianopia, where injury to one side of the brain affects the contralateral visual field in each eye

The venous system exists to drain blood away from the CNS, returning it to the heart and pulmonary area for circulation

The venous system exists to drain blood away from the CNS and return it to the heart and pulmonary area

The inferior and superior sagittal sinuses serve as major pathways for blood to drain into and away from the CNS. This occurs through the confluence, followed by the transverse sinus and jugular vein

A stroke is sudden and unexpected damage to brain cells, leading to symptoms lasting more than 24 hours in the parts of the body controlled by those affected cell

Stroke occurs when the blood supply to part of the brain is suddenly disrupted, either due to blockage of an artery or bleeding within the brain

Without blood flow, there is no oxygen supplied to brain cells, resulting in the death of neural tissue

Symptoms of a stroke vary depending on which area of the brain is affected

The two major types of strokes are ischemic stroke, caused by blockage of an artery, and hemorrhagic stroke, caused by bleeding within the brain

Ischemic stroke is the most common cause of stroke

In an ischemic stroke, the artery supplying vital nutrients to the brain becomes blocked

A hemorrhagic stroke involves a brain hemorrhage, which happens when an artery bursts inside the brain