Flashcards
Further Anatomy of the Brain (Practical)
Cards in this deck (111)
- 1What are the 3 primitive brain vesicles?Prosencephalon
Mesencephalon
Rhombencephalon - 2Wha does the prosencephalon differentiate into?Telencephalon = cerebral hemisphere and basal nuclei
Diencephalon = thalamus and hypothalamus - 3What are the four outgrowths of the diencephalon and what is their function?Dorsal = pineal gland (circadian rhythms - modulates sleep/wake cycle and seasonal breeding via melatonin)
Lateral = eyes
Ventral = pituitary gland (hormone production) - 4What condition is caused by failure of the rostral neuropore to close?Anencephaly
Brain not properly enclosed - 5What condition is caused by failure of the caudal neuropore to close?Spina bifida
Dermoid sinus is a minor form of this - 6Where does the spinal cord lie in relation to the vertebrae?Vertebral canal formed by successive vertebral foraminae
- 7Give 3 features of the atlasNo dorsal spinous process
No body
Articulates cranially with occipital condyles - 8Give 3 features of the axisVery large spinous process
Cranial projection called the dens which articulates with C1
Caudal articular process (part of spinous process) which articluates with C3 - 9What is unusual about the junction between C1 and C2 vertebrae?No intervertebral disc
- 10How can cervical vertebrae be distinguished from vertebrae in other regions?Transverse foraminae
C7 has longer spinous process - 11How can thoracic vertebrae be distinguished from vertebrae in other regions?Prominent spinous processes
- 12How can lumbar vertebrae be distinguished from vertebrae in other regions?Prominent transverse processes
- 13What is the vertebral lamina?Flattened part of vertebral arch which forms roof of spinal canal
- 14What is the vertebral pedicle?Attaches lamina to vertebral body
- 15What is acquired vertebral malformation-malarticulation?Developmental bone disorder causing stenosis (narrowing) of the vertebral canal, leading to compression of the cervical spinal cord
- 16How does the diameter of the spinal cord vary?Wider cranially and narrows caudally
- 17Why is there a discrepancy between the length of the vertebral canal and the length of the spinal cord?Differential growth of vertebrae (faster) compared to spinal cord leads to cranial shift of spinal cord segments
- 18Where do spinal cord segments L5-S6 lie in the dog?Between vertebrae L4 and L5
- 19What is the name for the x-ray technique used to outline the spinal cord by injecting a contrast dye into the CSF under general anaesthesia?Myelography
- 20Where could contrast dye be injected into the CSF?Cisterna magna
Lumbar cistern - 21What type of nerve fibres do the dorsal roots contain?Sensory only
- 22Where are the cell bodies of nerves within the dorsal root located?Dorsal root ganglion
- 23How can the dorsal and ventral aspect of the spinal cord be distinguished?Dorsal median groove or septum (shallow)
Ventral median fissure (deeper) - 24Where is the grey matter in the spinal cord and what does it contain?Centrally located
Contains cell bodies of somatic neurones, dendrites, glia and unmyelinated axons - 25In which region of the spinal cord is there a lateral horn?Thoracolumbar
- 26What does the lateral horn contain?Cell bodies of preganglionic general visceral efferent neurones (sympathetic)
- 27What does the dorsal horn contain?Sensory neurone cell bodies
- 28What does the ventral horn contain?Somatic motor neurone cell bodies
- 29What is the central canal of the spinal cord continuous with?4th ventricle
- 30What is the embryological origin of the central canal?Lumen of neural tube
- 31How is the white matter in the spinal cord arranged?Columns called funiculi - dorsal, lateral and ventral
Composed of fasciculi (axons surrounded by a perineurium which have the same origin, destination and function) - 32Why is there more white matter than grey matter at cervical regions of the spinal cord?Myelinated axons travel from brain to rest of body so fewer further caudally as they have already supplied more cranial structures such as forelimbs and hindlimbs
- 33In which spinal cord segments will preganglionic sympathetic neurones be found?Thoracolumbar
- 34In which spinal cord segments will preganglionic parasympathetic neurones be found?Sacral intermediate grey matter (between dorsal and ventral horns)
- 35What is the lateral ventricle surrounded by in transverse section?Caudate nucleus
- 36What is the translation of dura mater?Tough mother
- 37What fold of the dura mater occupies the longitudinal fissure and what is its function?Falx cerebri
Contains dorsal and ventral sagittal venous sinus
Separates two cerebral hemispheres
Prevents medio-lateral touching of brain parts - 38What fold of dura mater occupies the transverse fissure and what is its function?Tentorium cerebelli
Contains transverse venous sinus
Supports occipital lobe of cerebral hemispheres
Prevents rostro-caudal touching of brain parts - 39What happens to the spinal dura as it enters the foramen magnum?Closely adherent to bone - epidural space obliterated
- 40What collective term is often given to the arachnoid mater and pia mater?Leptomeninges
- 41What does the epidural space contain?Fatty tissue
- 42What does the subarachnoid space contain?Cerebrospinal fluid
- 43Is the subarachnoid space the same thickness the entire length of the spinal cord?No - varies in thickness causing pooling of CSF in certain areas called cisterns e.g. lumbar cistern and cisterna magna
- 44How is the spinal cord tethered in place caudally?Filum terminale
- 45What is the preferred site for epidural anaesthesia in the dairy cow?Epidural space between the periosteum and the dura mater
Between coccygeal vertebrae 1 and 2 - 46What limits cranial diffusion of epidural anaesthetic?Fat in epidural space
- 47Why is careful dosage of epidural anaesthetic important?Too high will block L4-L6
Femoral, sciatic or obturator nerves - 48What conditions are epidural anasthesia used for in the cow?Anaesthetise pudendal nerve = analgesia of perineum and pelvic viscera
Used to prevent straining e.g. in prolapse or dystocia - 49What does the epidural space contain as well as fatty tissue?Veins draining spinal cord
- 50What are the consequences of erroneously injecting local anaesthetic into the CSF?Anaesthetic toxicity - death of animal due to cardiovascular depression
- 51What are ventricles?Fluid-filled spaces in the brain continuous with the central canal of the spinal cord
They are lined with choroid plexus tissue which produces CSF - 52What is choroid plexus tissue made up of?Group of arterioles, each coated with a layer of pia
Layer of cuboidal epithelium (ependymal cells) - 53Give 3 functions of cerebrospinal fluidShock absorber for protection
Circulates nutrients and chemicals
Removes waste products to maintain a suitable environment for the CNS (chemical buffer) - 54Give 2 reasons for collecting cerebrospinal fluid from a patientTest for infection e.g. meningitis (high protein and white blood cell count)
Blood indicates subarachnoid haemorrhage - 55What could be suspected if a sample of cerebrospinal fluid has a high protein content?Can indicate tumour, bleeding, injury or inflammation
Blockage of CSF flow causes rapid accumulation of protein in the lower spinal area - 56What clinical condition can occur after blockage of CSF flow at the midbrain aqueduct due to a tumour, for example?Hydrocephalus
- 57How does cerebrospinal fluid exit the lateral ventricle?Interventricular foramen
- 58What is the fate of CSF from the fourth ventricle?Can pass into central canal
Can also pass straight into subarachnoid space of spinal cord via lateral apertures - 59What is the location of the vagosympathetic trunk?Neck -> branches recurrent laryngeal nerve at base of heart -> vagus nerves branch into dorsal and ventral before diaphragm
- 60What is the location of the paravertebral chain?Just below vertebrae
- 61Where are the stellate and middle cervical ganglia located?Between neck and heart
Dorsal = stellate/ cervicothoracic ganglion
Ventral = middle cervical ganglion - 62What do the sympathetic chain ganglia contain?Cell bodies of postganglionic sympathetic neurones
Preganglionic neurones have cell bodies in lateral horn of spinal cord - 63What 3 types of nerve fibres are found in the vagosympathetic trunk?Parasympathetic
Sympathetic
Recurrent laryngeal nerve (somatic afferent and efferent) - 64Is the paravertebral chain sympathetic or parasympathetic?Sympathetic
- 65Are the stellate and middle cervical ganglion sympathetic or parasympathetic?Sympathetic
- 66How may damage to the cranial part of the sympathetic chain be demonstrated clinically?Constriction of pupil due to loss of sympathetic innervation to dilator pupillae muscle
Caused by Horner's syndrome - deficit in sympathetic supply causing parasympathetic system to override - 67Which branch of the vagus nerve is given off at the base of the heart?Recurrent laryngeal nerve
Runs back up neck to supply motor and sensory innervation to laryngeal muscles including dorsal cricoarytenoid muscle and laryngeal mucosa - 68What is laryngeal hemiplegia?Denervation of the dorsal cricoarytenoid muscle by the recurrent laryngeal nerve
- 69What are the 2 main fibre types found in the spinal nerves?Somatic afferent
Somatic efferent - 70Describe the pathway of a mechanoreceptor impulse to spinal cordRelayed to relevant spinal nerve and then to dorsal root ganglion where cell body of receptor lies
Enters dorsal horn of spinal cord - 71Why is the sciatic nerve easy to identify?Very large
- 72What does the sciatic nerve innervate?Hamstrings (hip extension and stifle flexion)
Branches into tibial and peroneal nerves
Sensory to caudal and lateral asects of the limb - 73Which muscles are innervated by the femoral nerve?Quadriceps (stifle extension)
Hip flexors:
Rectus femoris
Sartorius
Iliopsoas - 74What muscles does the obturator nerve innervate?Adductor muscles:
Gracilis
Adductor
Pectineus - 75Which muscles does the tibial nerve innervate?Minor stifle flexors: gastrocnemius, SDF, popliteus
Hock extensors: gastrocnemius, SDF
Digit flexors - 76Which muscles does the fibular nerve innervate?Hock flexors: cranial tibial and peroneus longus
Digit extensors - 77What are the nerves supplying the hindlimb collectively called as they emerge from the spinal cord?Lumbosacral plexus
- 78Give the 3 types of somatic sensory neuroneExteroreceptive
Proprioceptive
Special (sight, hearing, balance) - 79What is the function of visceral sensory neurones?Transmit stimuli from blood vessels, mucous membranes and viscera
Special senses (smell and taste) - 80What do somatic motor neurones innervate?Skeletal muscle
- 81What do visceral motor neurones innervate?Involuntary muscle cells and glands
Branchial division innervates striated muscle embryologically associated with branchial arches e.g. pharyngeal and laryngeal muscles - 82What are the 2 categories of visceral motor neurones?Sympathetic
Parasympathetic - 83Where is the hippocampus located?Caudal to caudate nucleus in lateral ventricle
- 84Describe the blood supply to the cerebrum and cerebellumRostral cerebral artery = medial
Middle cerebral artery = most of cerebral hemispheres
Caudal cerebral artery = dorsal cortex of occipital lobe
Rostral and caudal cerebellar arteries - 85Where do the internal carotid arteries enter the skull in the dog?Carotid siphon in base of skull
- 86Where does the basilar artery enter the skull?Foramen mangum
- 87Where do the maxillary arteries come from?Branches of the external carotid arteries which anastomose with the internal carotid arteries
- 88What is the most important blood supply to the brain in the dog?Internal carotid arteries
Maxillary and basilar less important - 89What happesn to the internal carotid arteries during a cow's development?Proximal 2/3 of internal carotid artery occlude before 18 months
- 90What is the primary blood supply to the brain in the ox?Maxillary artery
Anastomosis between vertebral and maxillary artery connecting to distal 1/3 of internal carotid artery - 91Give the arrangement of vertebrae in a dogC7
T13
L7
S3
Cd 20-23 - 92Where does the spinal cord end in a dog?L6/L7
Cranial sacrum in small animals - 93Give the arrangement of vertebrae in a catC7
T13
L7
S3
Cd 20-23 - 94Where does the spinal cord end in a cat?L6
- 95Give the arrangement of vertebrae in a horseC7
T18
L6
S5
Cd 20 - 96Where does the spinal cord end in a horse?Cranial quarter of sacrum (S2)
- 97Give the arrangement of vertebrae in a cowC7
T13
L6
S5
Cd 18-20 - 98Where does the spinal cord end in a cow?L6/S1
- 99What is the term for the tapering at the caudal end of the spinal cord?Conus medullaris
- 100What is the filum terminale?Attachment of meninges to coccygeal vertebrae
- 101What is the cauda equina?Bundle of spinal nerves remaining after termination of the spinal cord
- 102Give 3 consequences of an intervertebral disc protrusion between L4 and L5?Loss of somatic innervation to hindlimbs
Loss of parasympathetic innervation to pelvic organs
Sensory deficit to pudendum - 103What is the term for the structures that attach the pia and arachnoid mater?Pia trabeculae
- 104What does the pia mater attach to?Astrocytes that coat the surface of the central nervous system
- 105What forms the filum terminale?Fused meninges
- 106What is the ion composition of CSF?High potassium
High calcium
Low sodium - 107Why does CSF usually have a low protein and glucose content?Blood brain barrier impermeable to large molecules
- 108What is the consequence of femoral nerve paralysis?Cannot bear weight due to paralysis of quadriceps
- 109What is the consequence of obturator nerve paralysis?Leg splay due to paralysis of adductor muscles
- 110Give 2 consequences of fibular nerve paralysisKnuckling over of digit due to reduced extension
Sensory deficit - 111Give 2 consequences of tibial nerve paralysisTarsus sinking to floor due to reduced extension
Sensory deficit
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- BVSc Animal Health Science 2 (Neuroanatomy) Flashcards on Further Anatomy of the Brain (Practical), created by Florence Edwards on 03/12/2016.
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