Week 2

Question 1

What are the 3 main areas of the brain stem?

Answer 1

• Midbrain
• Pons
• Medulla

Question 2

What is the function of the brain steam?

Answer 2

Connects the spinal cord to the brain
- A passage way for ascending (sensory pathways) and descending (motor pathways)

Question 3

Efferent

Answer 3

Motor

Question 4

Afferent

Answer 4

sensory

Question 5

What is the function of the spinal cord?

Answer 5

• Connects the CNS to the PNS

Question 6

Where is the spinal cord located?

Answer 6

Within the vertebral cannel - protects it and ends at L1 or L2
- At the lumbar and sacral levels the spinal nerves descend in a leash like arrangement

Question 7

In the spinal cord what is the Cauda equina?

Answer 7

Long nerves roots from L1 that is required to extend downward to our lumbosacral vertebral column to then go out and innovate our legs

Question 8

What is filum terminale in the spinal cord?

Answer 8

Connective tissue extending from the cord and terminating at the coccyx

Question 9

In the spinal cord what is the Conus medullaris?

Answer 9

Around L1/L2 area – marking the end of the spinal cord

Question 10

What are meninges and what are the 3 layers in the spinal cord?

Answer 10

3 layers of connective tissue that protect the spinal cord
1. Dura mater
2. Arachnoid
3. Pia mater

Question 11

What is the role of the dura mater?

Answer 11

Toughest fibrous membrane that is tightly adherent to the inside of the skull - protecting it

Question 12

What is the role of the arachnoid mater?

Answer 12

Closely apposed and loosely attached to the dura mater

Contains arachnoid granulations – allow the absorption of cerebrospinal fluid

Question 13

What is the role of the pia mater?

Answer 13

Extremely thin and delicate

Follows the contours of the brain

Helps protect dense rich blood supply of underlying neural tissue

Question 14

What is the role of the subarachnoid space?

Answer 14

Between the arachnoid and pia mater

Filled with cerebrospinal fluid – cover the central nervous system – provides nutrients and acts as protection

Protective role as it offers buoyancy and cushions against sudden head movements

Question 15

What structure produces cerebrospinal fluid?

Answer 15

The choroid plexus

Question 16

Where is cerebro spinal fluid produced?

Answer 16

Inside the brain, in the 4 fluid filled ventricles of the ventricular system

Question 17

What is the central canal?

Answer 17

A passageway for cerebral spinal fluid to come through

Question 18

What is the dorsal posterior horn?

Answer 18

Site of termination of many afferent neurons via root. Receives our primary afferent sensory fibers from our dorsal roots. Processes sensory information
- A component of spinal grey matter

Question 19

What is the ventral (anterior) horn?

Answer 19

Contains lower motor neurons (efferent)
- A component of spinal grey matter

Question 20

What is the lateral horn?

Answer 20

Processes automatic information (only at T1-L2 spinal segments)

Question 21

What are dermatomes?

Answer 21

Areas of the skin innervated by a single spinal nerve

Question 22

What are myotomes?

Answer 22

A group of muscles innovated by a single spinal nerve

Question 23

What are spinal cord injuries and what are the 2 pahses?

Answer 23

• A damage to the spinal cord that may cause temporary or permanent change to function of the cord
• Phase 1 – primary damage – Happens immediately when the injury takes place
  -Phase 2 – secondary damage – initiated by the trauma but occurs over a period of hours, days or months

Question 24

What is a complete spinal cord injury?

Answer 24

Complete loss of sensory and motor function

Question 25

What is a Incomplete spinal cord injury?

Answer 25

Preservation of sensory and/or motor function

Question 26

What is quadriplegia?

Answer 26

Paralysis of the upper and lower limbs as a result of damage to the cervicle area

Question 27

What is paraplegia?

Answer 27

Damage to the spinal cord below the cervical area, sparing arm function - at the lumbar region

Question 28

What are segmental nerve lesions?

Answer 28

- Injuries affecting specific segments of a nerve - Occurs at the horn, root or spinal nerve - Altered or lost sensation in a dermatome at that level -Decreased or lost stretch muscle power in a myotome at that level - Decreased or lost stretch reflex

Question 29

What do peripheral nerve lesions cause?

Answer 29

- Smaller isolated impact - Altered or lost sensation in a peripheral nerve distribution - Decreased or lost muscle power in a peripheral nerve distribution - Decrease or lost stretch reflex

Question 30

What is the ventricular system?

Answer 30

4 fluid filled cavities in the brain that protects the brain from chemicals and trauma

Question 31

What is cerebrospinal fluid?

Answer 31

Acts as a shock absorber, removes waste and keeps pressure balanced in the brain

Question 32

How does the cerebro-spinal fluid circulate?

Answer 32

Once CSF is made, it flows through these ventricles and enters the subarachnoid space, which surrounds the brain and spinal cord. It eventually gets absorbed back into the bloodstream through structures called arachnoid granulations.

Question 33

What arteries make up the circle of Willis?

Answer 33

- Anterior cerebral artery - Middle cerebral artery - Posterior cerebral artery

Question 34

What are anastomoses in the circulatory system?

Answer 34

Serve as back up routes for blood supply in case there is a vessel being block

Question 35

Where does the ACA supply?

Answer 35

Supplies the medial cortical surfaces of the frontal lobe with are involved in motor for the lower limb via the corticospinal tract, also has a key role in higher order cognitive function Supplies medial cortical surfaces of the partial lobe – receives and processes sensory input from the lower limb Supplies prefrontal cortex

Question 36

Where does the MCA supply?

Answer 36

Majority of the lateral surfaces of the brain - front, parietal, temporal - Supplies head, upper limb and thoracic areas of motor and sensory cortex - Hearing areas - Language - Frontal cortex - Basal ganglia

Question 37

Where does the PCA supply?

Answer 37

- Visual areas - Subthalamic nuclei - Hippocampus

Question 38

What is a stroke?

Answer 38

A sudden and unexpected damage to brain cells that causes symptoms that last more than 24 hours in the parts of the body controlled by those cells when blood supply to part of the brain is distrupted

Question 39

What is a Ischemic stroke or Brain Infarction ?

Answer 39

Embolus (formed elsewhere in the body) or thrombus (formed from the heart) lodges in a vessel, obstructing blood flow – causing blockage Blockage deprives an area of blood, resulting in almost immediate onset of deficits

Question 40

What is a hemorrhagic stroke?

Answer 40

- Burst - Deprives the downstream vessel of blood and the extravascular blood exerts pressure on the surrounding brain - Present with the worst deficits within hours of onset and then improvement occurs as pooling of blood decreases

Question 41

What is a subarachnoid stroke?

Answer 41

Bleeding in the subarachnoid space Causes sudden, excruciating headache with a brief loss of consciousness Cause is most often from head trauma

Question 42

What does a stroke in the ACA cause?

Answer 42

- Loss of fine touch in contralateral lower limb - Contralateral hemiplegia and gait difficulties - Lack of emotional expressiveness - Urinary incontinense

Question 43

What does a stroke in the MCA cause?

Answer 43

- Contralateral hemiplegia - face and upper limb motor impaired - Impairment of non-verbal communication - Contralateral sensory loss - face and upper limb sensation

Question 44

What does a PCA cause?

Answer 44

- Difficulties with eye movement - Blindness - Memory loss