The Brain (Theme A) Flashcards
Although the relative size of the components of vertebrate brains can vary in size, they all have a common plan - what is this?
Forebrain - Midbrain - Hindbrain (including the cerebellum)
The human forebrain is relatively _______, compared to other vertebrates
Large
What are the 4 components of the brainstem?
- Medulla
- Pons
- Midbrain
- Cerebellum (*which is sometimes considered as separate)
Which 2 components make up the forebrain?
- Telencephalon
- Diencephalon
Why does the human brain have 2 anatomical axis?
Due to the flexure in the brain between the axis (cephalic flexure)
*other vertebrates don’t have such a pronounced flexure
Where are the 2 anatomical axes of the brain?
Axis A - Forebrain
Rostral (forehead side) —> Caudal
Superior / Dorsal (top of head) —> Inferior / Ventral
Axis B - Brainstem, cerebellum, spinal cord
Rostral (top of spine) —> Caudal
Dorsal (back side) —> Ventral (stomach side)
What is the flexure between the 2 anatomical axes of the brain called?
Cephalic flexure
What are the 4 planes of section (of the brain)?
Horizontal - cut horizontally across the head
Sagittal - goes down the midline of the head
Oblique - rarely used
Coronal (transverse) - cut down the head, like ear to ear
*Different to transverse section of the SC, as the axis changes
What does the grey matter contain?
Cell bodies
What does the white matter contain?
Axons
Why is white matter white coloured?
Myelin sheaths of axons - myelin is a pale colour
What are the 3 Brain Meninges? (From outer to inner)
Dura Mater
Arachnoid Mater
Pia Mater
What does the arachnoid mater contain?
CSF
Which of the Meninges is adherent to the surface of the brain?
Pia Mater
Which of the Meninges lines the skull cavity?
Dura Mater
What folds does the Dura Mater form?
- Falx Cerebri
- Tentorium Cerebelli
Where is the falx cerebri?
Fold in the middle of the brain
Where is the tentorium cerebelli?
Between the telencephalon & cerebellum
What are 3 descriptive properties of the Dura Mater?
Tough, smooth, fibrous
How many ventricles are there in the ventricular system?
4
What do the ventricles in the ventricular system contain?
Cerebrospinal fluid (CSF)
How many lateral ventricles are there?
2
What are the (large) lateral ventricles associated with?
Telencephalon
What is the 3rd ventricle associated with?
Diencephalon
What is the 4th ventricle associated with?
Brainstem
The interventricular foramen connects which ventricles?
The lateral ventricles with the 3rd ventricle
The cerebral aqueduct connects which ventricles?
3rd & 4th
Where does the cerebellum attach? (Dorsally or ventrally?)
Dorsally (in axis B)
Which ventricle is associated with the brainstem?
4th
What type of nerves emerge from the brainstem?
Cranial nerves
How many pairs of cranial nerves are there?
12
The cerebellum is attached dorsally to the pons via which structures?
Peduncles
What labels / notation is used to refer to cranial nerves?
Roman numerals (I-XII)
CN1-12
Which part of the brain are the cranial nerves most associated with?
Brainstem
What are the 3 types of cranial nerves?
- Sensory only
- Motor only
- Mixed sensory & motor (contain both types of fibres)
What is the origin of CN1 & CN2
The forebrain