Cranial cavity and brain Flashcards
What does the coronal suture do?
Joins the frontal bone to the 2 parietal bones
What does the sagittal suture do?
Joins each parietal bone together along the midline
What does the lambdoid suture do?
Joins the occpital bone to the 2 parietal bones
Where is the bregma?
Junction between the frontal and 2 parietal bones
Where is the lambda?
Junction between the occipital and 2 parietal bones
What are the components of the temporal bone?
Squamous part, zygomatic mastoid and styloid processes, external acoustic meatus and petrous part
What is the significance of the anterior cranial fossa?
Cribriform plate of the ethmoid bone contains small perforations through which the small olfactory nerves pass
What are the 4 foramen in the middle cranial fossa?
Foramen rotundum, foramen ovale, foramen spinosum and foramen lacerum
What are the important holes in the posterior cranial fossa?
Foramen magnum, internal acoustic meatus, jugular foramen and hypoglossal canal (foramen)
What does the prosencephalon become?
Telencephalon and diencephalon
What does the mesencephalon become?
Stays as mesencephalon
What does the rhombencephalon become?
Metencephalon and myelencephalon
What structures do the telencephalon and diencephalon become?
Cerebral hemisphere
Thalamus, hypothalamus, optic nerve and retina, pituitary
What do the metencephalon and myelencephalon give rise to?
Pons and cerebellum (1) and medulla oblongata (2)
What is the biggest connection the L and R hemispheres?
Corpus callosum - bunde of white matter joining the cerebral hemispheres together.
What is the interventricular foramen?
- small structures
- between fornix and anterior pole of thalamus
- connects lateral ventricles to third ventricle
What is the insula?
- thin ribbon of grey matter
- lies deep to lateral sulcus
- insulated by the frontal and temporal lobes
Where is the third ventricle found?
Between the two thalami
What does the third ventricle contain?
Hypothalamus
What is the cerebral aqueduct?
A small cavity in the midbrain that connects the third ventricle to the fourth ventricle
What are subarachnoid cisterns?
- compartments within subarachnoid space
- pia mater and arachnoid membrane are not in close approximation
- CSF forms pools/cisterns –> provides the brain with nutrients, allow for solute exchange, basic mechanical/functional support for the brain
What are arachnoid granulations?
- small outpouching of the arachnoid mater
- protrudes into the venous sinuses
- allow CSF to exit the subarachnoid space and enter blood stream
What are the three layers of meninges?
Dura, arachnoid and pia mater
Describe dura mater
- tough mother
- outermost layer, fibrous protective layer which adheres to the periosteum of the skull
Describe arachnoid mater
- spidery mother
- middle layer
- much more delicate membrane, lines the inner surface of the dura mater
Describe pia mater
- delicate mother
- adheres to the brain surface and follows its contours
What are the three types of haematoma?
1) Extradural
2) Subdural
3) Subarachnoid
Outline extradural haematoma
- between skull and dura
- arterial blood –> middle meningeal artery
- result of skull fracture –> brain damage due to increased pressure
Outline subdural haematoma
- between dura and arachnoid
- venous blood –> superior cerebral vein
- result of damage to brain
Outline subarachnoid haematoma
- between arachnoid and pia
- usually result of aneurysm, skull fracture or cerebral laceration –> meningitis irritation, severe headache, stiff neck and often loss of consciousness
