Brain Anatomy Lecture 1 Flashcards
What are the different components of the brain?
1 - Forebrain = Prosencephalon
(Cerebrum)
–> Telencephalon
–> Diencephalon
2 - Midbrain = Mesencephalon
3 - Hindbrain = Rhombencephalon
- -> Pons - -> Medulla = Myelencephalon - -> Cerebellum = Metencephalon
What is the composition of the brainstem?
- Midbrain = Mesencephalon
- Pons
- Medulla = Myelencephalon
+ sometimes includes Cerebellum = Metencephalon
What are the 3 axes of the brain?
–> similar to rest of body
- Lateral-medial
- Dorsal-ventral
- Rostral-caudal (anterior-posterior
mouth to tail)
What are the 2 anatomical axes of the human brain?
What is this due to?
Axis A
–> Forebrain
Axis B
–> Brainstem, cerebellum and spinal cord
This is due to the flexure in the brain at that point (not so pronounced in other vertebrates)
How many flexures are there in the vertebrate brain? What do they separate?
2 flexures separating:
- forebrain from midbrain
- midbrain from hindbrain
What are the main planes of section?
- Horizontal (separates top of brain from bottom) - Sagittal (separates left from right side) - Transverse/frontal/coronal (Separates front from back)
- Oblique
(rarer)
Meninges: what are the main layers and their characteristics?
From in to out:
1 - Pia Mater
2 - Arachnoid Mater
3 - Dura Mater --> lines the skull cavity --> formed into folds (Falx cerebri and Tentorium cerebelli) --> tough, smooth, & fibrous
How many ventricles are there?
What do they contain?
- 2 lateral ventricles: large and associated with telencephalon
- 3rd ventricle associated with diencephalon
- 4th ventricle associated with brainstem
–> all contain cerebro-spinal fluid (CSF)
What connects the third and fourth ventricles?
cerebral aqueduct
Where do the majority of cranial nerves emerge from?
brainstem
What are cerebellar connections points called?
peduncles
–> two stalks that attach the cerebrum to the brainstem
What is the cerebellum attached to?
the pons
Describe the arrangement of grey and white matter in the cerebellum?
deep cerebellar nuclei in centre
- -> bits of grey matter in white matter
- -> on outside: cerebellar cortex
Where is the brainstem/cerebellum positioned in the skull?
Posterior cranial fossa
How many cranial fossas are there/what are they called?
three:
- Anterior cranial fossa
- Middle cranial fossa
- Posterior cranial fossa
What do you call the fold of the dura mater?
Tentorium cerebelli
–> an extension of the dura mater that separates the cerebellum from the inferior portion of the occipital lobes
How many cranial nerves are there?
12 cranial nerves
- some are sensory (e.g. CN1, 2, 8)
- some are motor (e.g. CN3, 4, 6, 11, 12)
- some are mixed = contain both motor and sensory fibres (e.g. CN5, 7, 9, 10)
What is the diencephalon composed of?
- Thalamus
- Epithalamus
- Hypothalamus
- Pineal (epiphysis)
- Pituitary (hypophysis)
Where does the optic nerve (cranial nerve 2) originate?
From the hypothalamus in the diencephalon
How many principle lobes are there in the cerebral cortex? Name them
Four principle lobes:
- frontal lobe
- parietal lobe
- temporal lobe
- occipital lobe
What are the main fissures/sulci of the cerebral cortex?
Fissures separate lobes:
- Longitudinal cerebellar fissure (down middle from front to back of brain)
- Central sulcus (separates frontal lobe from parietal lobe)
- Lateral sulcus (temporal lobe)
- Parieto-occipital sulcus (separates parietal and occipital lobes)
What are the “valleys” and “hills/ridges” of the cerebral cortex called?
valleys = sulci ridges = gyri
What are the deep cerebral ganglia?
- Deep cerebral grey matter within the white matter
- Various names describe groupings of these nuclei: basal ganglia, corpus striatum etc…
- Associated with movement disorders: Parkinson’s disease and Huntington’s disease
What is the circle of Willis?
A circular anastomosis of
arteries from which almost all
the brain’s blood is supplied
What are the three main arteries in the brain?
- Anterior Cerebral Artery
- Middle Cerebral Artery
- Posterior Cerebral Artery