Anatomy Flashcards
(24 cards)
HINDBRAIN
The hindbrain comprises:
-The myelencephalon (medulla oblongata and lower part of the fourth ventricle)
–The metencephalon (pons, cerebellum and intermediate part of fourth ventricle), and
-Isthmus rhombencephalon.
The medulla oblongata opens into the fourth ventricle.
The nucleus ambiguous gives rise to fibres of the accessory, vagus and glossopharyngeal nerves.
The locus caeruleus receives sensory fibres from the trigeminal nerve.
The three parts of the cerebellum include the vermis and the two hemispheres which are confluent.
The pyramids (spinothalamic tracts) are medial to the olives.
The median portion of the cerebellum is the vermis and the cerebellar hemispheres lie lateral to it.
Brachial Plexus
-Anterior rami of C5 to T1.
-Roots are located in the posterior triangle.
-Pass between the scalenus anterior and medius.
BRAIN TUMOURS METS
Tumours that most commonly spread to the brain include:
lung (most common)
breast
bowel
skin (namely melanoma)
kidney
Glioblastoma multiforme
Glioblastoma is the most common primary tumour in adults and is associated with a poor prognosis (~ 1yr).
Histology: Pleomorphic tumour cells border necrotic areas.
Meningioma
The second most common primary brain tumour in adults.
They arise from the arachnoid cap cells of the meninges.
Histology : Spindle cells in concentric whorls and calcified psammoma bodies.
Vestibular schwannoma
Benign tumour arising from the eighth cranial nerve (vestibulocochlear nerve). Often seen in the cerebellopontine angle.
Neurofibromatosis type 2 is associated with bilateral vestibular schwannomas.
- Histology: Antoni A or B patterns are seen. Verocay bodies (acellular areas surrounded by nuclear palisades
Pilocytic Astrocytoma
The most common primary brain tumour in children
* Histology: Rosenthal fibres (corkscrew eosinophilic bundle)
Medulloblastoma
A medulloblastoma is an aggressive paediatric brain tumour.
Histology: Small, blue cells. Rosette pattern of cells with many mitotic figures.
Ependymoma
Commonly seen in the 4th ventricle
* May cause hydrocephalus
* Histology: perivascular pseudorosettes
Oligodendroma
Benign, slow-growing tumour common in the frontal lobes
* Histology: Calcifications with ‘fried-egg’ appearance.
Haemangioblastoma
Vascular tumour of the cerebellum
* Associated with von Hippel-Lindau syndrome
* Histology: foam cells and high vascularity
Pituitary Adenoma
Pituitary adenomas are benign tumours of the pituitary gland. They are either secretory (producing a hormone in excess) or non-secretory. They may be divided into microadenomas (smaller than 1cm) or macroadenoma (larger than 1cm).
Craniopharyngioma
Most common paediatric supratentorial tumour
- A craniopharyngioma is a solid/cystic tumour of the sellar region that is derived from the remnants of Rathke’s pouch. It is common in children, but can present in adults also. It may present with hormonal disturbance, symptoms of hydrocephalus or bitemporal hemianopia.
Cardiac action potential
Phase 0 Rapid depolarisation Rapid sodium influx
These channels automatically deactivate after a few ms
Phase 1 Early repolarisation Efflux of potassium
Phase 2 Plateau Slow influx of calcium
Phase 3 Final repolarisation Efflux of potassium
Phase 4 Restoration of ionic concentrations Resting potential is restored by Na+/K+ ATPase
Cardiac physiology
> > Left ventricular ejection fraction = (stroke volume / end-diastolic LV volume ) * 100%
Cardiac output = stroke volume x heart rate
Pulse pressure = Systolic Pressure - Diastolic Pressure
Systemic vascular resistance = mean arterial pressure / cardiac output
Cerebral perfusion pressure
CPP= Mean arterial pressure - Intra cranial pressure
Skier’s thumb, Gamekeepers thumb
Damage to ulnar collateral ligament
Iliopsoas abscess
Fever/back pain with pain on extension of the hip → iliopsoas abscess
BRAIN AREAS
Medial thalamus and mammillary bodies of the hypothalamus Wernicke and Korsakoff syndrome
Subthalamic nucleus of the basal ganglia Hemiballism
Striatum (caudate nucleus) of the basal ganglia Huntington chorea
Substantia nigra of the basal ganglia Parkinson’s disease
Amygdala Kluver-Bucy syndrome (hypersexuality, hyperorality, hyperphagia, visual agnosia
De Quervain’s tenosynovitis
De Quervain’s tenosynovitis: inflammation of the sheath containing the extensor pollicis brevis and abductor pollicis longus tendons.
APL-EPB
De Quervain’s tenosynovitis
Features
- pain on the radial side of the wrist
tenderness over the radial styloid process
- Abduction of the thumb against resistance is painful
Finkelstein’s test: the examiner pulls the thumb of the patient in ulnar deviation and longitudinal traction. In a patient with tenosynovitis, this action causes pain over the radial styloid process and along the length of extensor pollicis brevis and abductor pollicis longus
Management
- analgesia
- steroid injection
- Immobilisation with a thumb splint (spica) may be effective
- Surgical treatment is sometimes required.
De Quervain’s tenosynovitis
Condition in which the sheath containing the extensor pollicis brevis and abductor pollicis longus (APL-EPB) tendons is inflamed.
Pain on the radial side of the wrist/tenderness over the radial styloid process.
Brachial Plexus Injuries
Erb-Duchenne paralysis
damage to C5,6 roots
winged scapula
may be caused by a breech presentation
Klumpke’s paralysis
damage to T1
loss of intrinsic hand muscles
due to traction
De Quervain’s tenosynovitis
De Quervain’s tenosynovitis is a common condition in which the sheath containing the extensor pollicis brevis and abductor pollicis longus tendons is inflamed. It typically affects females aged 30 - 50 years old.
Features
pain on the radial side of the wrist
tenderness over the radial styloid process
abduction of the thumb against resistance is painful
Finkelstein’s test: the examiner pulls the thumb of the patient in ulnar deviation and longitudinal traction. In a patient with tenosynovitis this action causes pain over the radial styloid process and along the length of extensor pollisis brevis and abductor pollicis longus
Management
analgesia
steroid injection
immobilisation with a thumb splint (spica) may be effective
surgical treatment is sometimes required
