Nervous system S1 L2 - Organization of the Nervous System

Define The Nervous System

Define Neurology

Why do 10% of people in the UK consult a GP?

What are the basic functions of the nervous system?

Define CNS

How is it suspended?

How is the brain isolated from potentially harmful metabolites in the blood?

How is the brain surrounded?

Where is the CNS protected?

How does it become irreversibly damaged?

What are the two big divisions of the nervous system?

What is the CNS?

What are the components of the CNS?

What does the brain consist of?

What is the PNS?

What does the PNS consist of?

What do the spinal nerves do?

How many spinal nerves are there?

What do the cranial nerves do?

How many cranial nerves are there?

What is the forebrain called embryologically?

What are the components of the prosencephalon?

What is the midbrain called embryologically?

What is the hindbrain called embryologically?

What are the components of the rhombencephalon?

Define Central Nervous System

What are the lobes of the cerebral cortex?

Define cerebrum?

What is contained inside the cerebrum?

Where is CSF formed?

What are the functions of CSF?

How often is CSF changed?

Describe the circulation pathway of CSF

How does CSF leave the lateral ventricles?

How does CSF leave the 4th ventricle?

Then via the central canal, to where does it go?

Then via the foramina of Luschka and Magendie, CSF goes to where?

How is CSF absorbed?

Question

A blockage occurs in the cerebral aqueduct (of Sylvius).
Which ventricles will be dilated?

A) 4th ventricle only
B) 3rd and 4th ventricles
C) Lateral ventricles only
D) Lateral ventricles and 3rd ventricle
E) All ventricles

D) Lateral ventricles and 3rd ventricle

A patient has obstruction at the foramen of Monro.
Which structure will be dilated first?

A) 3rd ventricle
B) 4th ventricle
C) Lateral ventricle
D) Subarachnoid space
E) Central canal

C) Lateral ventricle

Which structure is responsible for CSF production?

A) Arachnoid villi
B) Choroid plexus
C) Dura mater
D) Pia mater
E) Cerebral cortex

B) Choroid plexus

A blockage at the foramina of Luschka and Magendie will cause:

A) Dilation of lateral ventricles only
B) Dilation of 3rd ventricle only
C) Dilation of all ventricles
D) No change
E) Only subarachnoid expansion

C) Dilation of all ventricles

Which of the following is the correct sequence of CSF flow?

A) 3rd → lateral → 4th → SA space
B) Lateral → 3rd → 4th → SA space
C) Lateral → 4th → 3rd → SA space
D) 4th → 3rd → lateral → blood
E) Lateral → SA → 3rd → blood

C) Lateral → 4th → 3rd → SA space

A lesion in the aqueduct of Sylvius causes dilation of:

A) Only 4th ventricle
B) Only lateral ventricles
C) Lateral and 3rd ventricles
D) All ventricles
E) Subarachnoid space only

C) Lateral and 3rd ventricles

CSF is mainly absorbed into the venous system through:

A) Choroid plexus
B) Foramen of Monro
C) Arachnoid villi
D) Central canal
E) Dural sinuses directly

C) Arachnoid villi

CSF is replaced approximately:

A) Once per week
B) Once per day
C) 2–3 times daily
D) 4–5 times daily
E) Continuously without turnover

D) 4–5 times daily

Define brainstem

What does the brain stem consist of?

What does the brain stem contain?

What pathways are found in the brain stem?

What nuclei are present in the brain stem?

What functions are controlled by collections of neurons in the brain stem?

From where does the spinal cord start?

Where does the spinal cord end?

A patient presents with sudden respiratory arrest and loss of heart rate control after brain injury.
Which structure is most likely damaged?

A) Cerebrum
B) Pons
C) Midbrain
D) Medulla oblongata
E) Spinal cord

D) Medulla oblongata

👉 لأنها تحتوي:

🔥 Cardiorespiratory center

(تنفس + نبض)

A lesion in the brainstem causes loss of both sensory and motor signals between the brain and body.
What is the main reason?

A) Damage to cranial nerves only
B) Damage to white matter pathways
C) Damage to cortex
D) Damage to cerebellum
E) Damage to meninges

B) Damage to white matter pathways

👉 لأن:

Ascending + descending pathways = white matter

A patient presents with double vision and inability to move both eyes together.
Which function is affected?

A) Balance
B) Arousal
C) Conjugate eye movement
D) Cardiorespiratory center
E) Motor cortex

✅ Answer: C) Conjugate eye movement

Damage to brainstem nuclei may affect which of the following?

A) Spinal reflexes only
B) Cranial nerve functions
C) Hormonal secretion
D) Memory only
E) Vision cortex

B) Cranial nerve functions

👉 لأن:

Cranial nerve nuclei موجودة في brainstem

A lesion affects the lower end of the medulla oblongata.
Which structure is most likely involved next?

A) Brain cortex
B) Cerebellum
C) Spinal cord
D) Thalamus
E) Pons

C) Spinal cord

👉 لأن:

spinal cord يبدأ من نهاية medulla

A patient presents with loss of consciousness (coma) after brainstem injury.
Which function is most likely affected?

A) Balance
B) Arousal
C) Eye movement
D) Motor output
E) Sensory input

B) Arousal

What is the cerebrum equal to?

What do all parts of the CNS consist of histologically?

Define white matter

Define gray matter

Where is gray matter distributed?

What is found on the surface of the cerebral hemisphere (CH) and its function?

What are the deep structures of CH and their functions?

Define cerebral cortex

Define the anterior part of cerebral cortex

Define the posterior part of the cerebral cortex

On what are Brodmann areas based?

How are Brodmann areas labeled?

What is Area 3 (S1)?

What is the function of Area 4 (M1)?

What is Area 6 (PMA)?

What is the function of Area 7?

What is Area 8 (SMA)?

What is the function of Area 17 (V1)?

What is Area 41 (A1)?

What is the function of Area 45?

Define the outer white matter

How is the outer white matter divided?

Define the posterior column

Define the lateral column

Define the anterior column

Define the gray matter

What is the gray matter concerned with?