Structure Of The Central Nervous System Flashcards
What is rostral?
→ Towards the front
What is caudal?
→ towards the back
Why do humans have a curve between dorsal and ventral?
→ we are bipedal
Where are humans symmetrical?
→ towards the midline
What do you call two things on the same side of the mid line?
→ ipsilateral
What do you call two things opposite of the midline?
→ Contralateral
What are two ways of describing a neuron projecting from the thalamus to the cortex?
→Thalamic efferent
→ Cortical afferent
What does an afferent describe?
→ Where the neuron is projecting to
What does an efferent describe?
→ Where a neuron is projecting from
What are your eyes in reference to your nose?
→ Lateral
What do afferent sensory fibres do?
→ Take sensory information from the periphery to the brain
What do efferent motor fibres do?
→ Motor instructions from the brain to the periphery
What are the cranial nerves?
→ Olfactory I
→ Optic II
→ Oculomotor III → Trochlear IV → Trigeminal V → Abducens VI → Facial VII → Vestibulocochlear VIII → Glossopharyngeal IX → Vagus X →Accessory XI → Hypoglossal XII
What type of nerves are the cranial nerves?
→ Sensory
→ Sensory
→ Motor → Motor → Both →Motor → Sensory →Both → Both → motor → motor
Where does the olfactory nerve project and what do they do?
→ Olfactory cortex - perception of smell
→ Hypothalamus - emotional aspects of smell
→ Amygdala
→ Hippocampus - odour memory
Where does the optic nerve project?
Retinal ganglion cells
↓
Lateral geniculate nucleus
↓
visual cortex (occipital lobe)
What type of innervation does the oculomotor nerve have and what do they do?
→ Motor - eyeball and eyelid movement
→ Parasympathetic - pupillary constriction and accomodation
What does the trochlear nerve do and what type of nerrve is it?
→ eyeball movement
→ motor
What type of nerve is the abducens and what does it do?
→ Eyeball movement
→ motor
What mediates up and down eye movement and what muscles are used?
→ CN III (oculomotor)
→ superior and inferior rectus muscles
What nerve and muscle mediates lateral eye movement?
→ CN III
→ Medial rectus
What nerve and muscle mediates diagonal downward movement?
→ CN III
→ Inferior oblique
What nerve mediates inward eye movement and what muscle is used?
→ CN IV (trochlear)
→ Superior oblique
What nerve mediates lateral eye movement and what muscle is used?
→ CN VI (abducens)
→ Lateral rectus
What are palpebrae muscles controlled by?
→ CN II
What are the three divisions of the trigeminal nerve?
→ Opthalmic
→ Mandibular
→ Maxillary
Where is sensory information transmitted to in the trigeminal nerve?
→ From the periphery down the trigeminal efferent to the somatosensory cortex
What types of axons does the facial nerve have and what are their functions?
→ Sensory - taste on anterior 2/3 of tongue
→ Motor - muscles of facial expression & stapedius muscle
→ Parasympathetic - salivary lands, lacrimal glands, glands of the nose and palate
What type axon does the vestibulocochlear nerve have?
→ Sensory
What are the functions and pathways of the vestibulocochlear nerve?
Hearing
cochlea cells
↓
medial geniculate nucleus (thalamus)
↓
auditory cortex (temporal lobe)
Balance vestibular hair cells ↓ Ventral posterolateral nucleus ↓ Vestibular cortex (temporal lobe)
What types of axons does the glossopharyngeal nerve have and what are their functions?
→ Sensory - pharynx, auditory tube in the middle ear, posterior third of the tongue, blood pressure changes in the aorta
→motor - swallowing
→ parasympathetic - salivary glands
What type of nerve is the vagus nerve and what are the functions?
→ Sensory - sensation of pain associated with viscera
→Motor - muscles for speech and swallowing
→ Parasympathetic - smooth muscle in : heart, lungs and abdominal organs
What type of axon does the accessory nerve have and what does it control?
→ Motor
→ Cranial : muscles of pharynx, larynx and soft palate
→ Spinal : head and neck muscles
What type of axon does the hypoglossal nerve have and what does it do?
→ Motor
→ Tongue for movement, swallowing and speedch
What are the three membranes in the skull?
→ Dura mater
→ Arachnoid membrane
→ Pia mater
What is the dura mater like?
→ tough and inelastic
What does the arachnoid membrane do?
→ Adheres layers together
What is the pia mater like and what does it do?
→ thin membrane
→ adheres closely to the brain
What is the subarachnoid space filled with?
→ CSF
Where is CSF made?
→ in the choroid plexus
Where does CSF go to and from?
→ Flows from the cerebrum ventricles down to the brainstem and spinal cord
Where does the CSF enter the subarachnoid space?
→ Via apertures near the cerebellum
Where is CSF absorbed?
→ by blood vessels in the subarachnoid space
What is the function of CSF?
→ to protect the brain from chemical and physical injury
→ regulates intracranial pressure
→ exchanging nutrients and waste products between blood and CNS
What is happening when someone is coding?
→ Intracranial pressure is so high that the brain has been pushed downwards into the brainstem
What arteries supply blood to the brain?
→ Vertebral arteries and carotid arteries
What structure to the arteries of the brain form and what kind of flow is there?
→ Circle of willis
→ turbulent flow
What is the lateral surface of the cerebrum supplied by?
→ Middle cerebral artery
What is most of the medial wall of the cerebral hemisphere supplied by?
→ anterior cerebral artery
What does the lymphatic system in the brain do and where is it?
→ within the dura mater
→ Delivers immune cells
What are the major regions of the brain
→forebrain
→brainstem
→cerebellum
What are the axis of the brain?
→Anterior-posterior
→Rostral-caudal
→Dorsal-ventral
→Superior-inferior
What are the planes of the brain?
→coronal
→horizontal
→sagital
What is the difference between anterograde and retrograde amnesia?
→unable to create new memories
→generally unable to recall past memories
What is the ventricular system?
comprises a series of interconnected, cerebrospinal fluid (CSF)-filled spaces that lie at the core of forebrain and brain stem.
What does the ventricular system comprise of?
→Lateral ventricles- paired structures
→Third ventricle
→Fourth ventricle- extends from cerebral aqueduct.
What is the choroid plexus?
responsible for producing the cerebrospinal fluid (CSF) that fills these ventricular spaces
What are the functions of the ventricular system?
→Protection of the brain (e.g. cushion for physical shocks)
→Transport (e.g. nutrients, waste products)
→ regulation of buoyancy. CSF reduces net weight
Where does the posterior circulation of the brain arise from?
→vertebral arteries
→Arise from subclavian arteries
Where do vertebral arteries converge?
near base of pons to form the basilar artery
What does the basilar artery split into?
→the right and left superior cerebellar arteries and the posterior cerebral arteries at the level of the midbrain
