brain & spinal cord Flashcards
what are the 3 major divisions of the brain?
- cerebrum
- cerebellum
- brainstem
what are gyri vs sulci?
- gyri are the folds/ ridges in the brain
- sulci are the** grooves** of the brain
what are fissures in the brain?
a fissure is a deeper groove (sulci) and can also be called sulcus
what did the brain develop from?
- the ectodermal neural tube
- the prosencephalon, mesencephalon & rhombencephalon
what is the** mesencephalon**?
midbrain - including the pons and cerebellum
(recap) what term does the arachnoid and pia matter make?
leptomeninx
where are the dural venous sinuses located?
between the periosteal and meningeal layers of the dura
Describe the arachnoid mater
- web like arachnpid trabeculae bridge
- not attached to dura, but the pressure of the CSF keeps it in direct contact
describe the pia mater
- gives brain a ‘shiny’ appearance
- adheres to brain surface and follows all contours
what are the properties of CSF?
- clear liquid
- contains glucose, proteins, ions and waste products
what are the functions of CSF?
- mechanical protection - shock absorber
- homeostasis function
- ciruclation - exchange of nutrients and waste between blood and nervous tissue
what cells are the CSF secreted by? Where are they located?
- the choroid plexus in the lateral ventricles
what are the ventricles of the brain?
- 2 lateral ventricles
- 3rd ventricle
- 4th ventricle
Describe the circulation of CSF
- CSF leaves the lateral ventricles through the intraventricular foramina (hole)
- CSF** enters the 3rd ventricle**
- it then passes through the cerebral aqueduct
- CSF then enters the ventricle and leaves through the median aperture & lateral aperture
- CSF then** enters subarachnoid space** which is continous with spinal chord
- CSF can** leave subarachnoid space **through the granulations into the venous system
What are the parts of the cerebrum?
- cerebral hemispheres - which are separated by the falx cerebri
- basal ganglia
what sulcus separates the frontal and parietal lobes?
the central sulcus
what does the transverse lateral sulcus separate?
separates the superior frontal and parietal lobes from the temporal lobes
what does the parieto-occipital sulcus separate?
- it separates the occipital lobes from the parietal & temporal lobes
what is the corpus callosum?
- a** broad band of nerve fibres** joining the 2 hemispheres of the brain
- remember it is a commisural fibre
what are the main functions of the cerebrum?
- conscious **thought process **
- **memory **storage
- conscious and subconscious regulation of skeletal muscle contractions
what are the basal nuclei?
the basal nuclei are paired masses of grey matter (cell bodies) in each cerebral hemisphere
what is the** function of the basal nuclei**?
- receive **input from cerebral cortex **
- provide motor output to other parts of the cortex via the thalamus
what is the limbic system in the cerebrum?
- the centre of emotional and behvaioural expression
what is the primary somatosensory area and where is it located?
- processes somatic sensations eg touch,proprioception, temperature etc
- posterior central gyrus
what is the primary motor area?
recieves and processes info about motor functions
what is the central core of the brain and what are are its contents?
diaencephalon
* contains epithalamus, thalamus (in walls of dianecephalon), **hypothalamus **(floor of dianecephalon)
what are the parts of the brainstem?
- midbrain
- pons
- medulla oblongata
- reticular formation
what are the functions of the midbrain?
- processes visual and auditory data
- maintains consciousness
what 2 important cranial nerves arise in the midbrain?
- CNIII - oculomotor
- IV- trochlear
what is the pons?
- pons = bridge
- between the mid brain and medulla oblongata
what are the functions of the pons?
- relays sensory information to cerebellum and thalamus
- subconscious somatic and visceral control
what cranial nerves are in the pons?
- trigeminal CN V
- CN VI-VIII (abudecens, facial, vestibulocochlear)
what cranial nerves arise from the medulla oblongata?
- glossopharyngeal (CN IX)
- vagus (CN X)
- hypoglossal (CNXII)
what is the function of the medulla oblongata?
- relays sensory info to the thalamus & other portions of the brainstem
- autonomic centres for reg of visceral function - cardiovascular, respiratory, digestive etc
What are the 2 hemispheres of the cerebellum separated by?
the vermis
what are the 3 lobes of the cerebellum?
- anterior lobe
- posterior lobe
- flocculonodular lobe
what are the 5 regions of the spinal chord?
- cervical
- thoracic
- lumbar
- sacrum
- 1 coccygeal nerve
what are the 3 layers of the spinal meninges?
- pia mater
- arachnoid mater
- dura mater
what does the grey matter in the spinal cord contain?
nerve cell bodies and fibres
what does the white matter of the spinal cord contain?
- myelinated fibres- may be ascending or descending
compare the **dorsal vs ventral horn **of the spinal cord
- **dorsal **-receive axons of sensory (afferent) neurons
* ventral - send out axons - motor (efferent) neurons
what is the acronym for remembering dorsal vs ventral
DAVE
* dorsal - afferent
* ventral - efferent
