Basic Sciences Paper Flashcards
How many layers does the scalp consist of and what are they?
5 layers. Mnemonic ‘SCALP’
Skin
dense Connective tissue
epicranial Aponeurosis
Loose Areolar connective tissue
Periosteum
What is the ‘danger area’ of the scalp?
loose connective tissue layer
it contains emissary veins = potential pathway for infection
What is the arterial supply to the scalp?
External Carotid Artery - 3 branches; superficial temporal, posterior auricular, occipital
Ophthalmic Artery
What is the deep venous drainage of the scalp?
pterygoid venous plexus
What innervates the scalp between the anterolateral forehead and the vertex?
Supraorbital nerve - branch of ophthalmic (Trigeminal)
What is the superficial venous drainage of the scalp?
superficial temporal, occipital, posterior auricular, supraorbital and supratrochlear veins
What does the Zygomaticotemporal nerve supply?
temple area of the scalp
branch of maxillary nerve (trigeminal)
What connects the scalp to the dural venous sinus and creates a potential infection route?
emissary veins
What nerve supplies the anteromedial forehead?
Supratrochlear nerve - branch of ophthalmic nerve (Trigeminal)
What is the innervation of the scalp?
Trigeminal Nerve
Cervical Nerve Roots C2 & C3
What innervates the scalp anterosuperior to the auricle?
Auriculotemporal nerve
What innervates the skin posterior to the ear?
Lesser occipital nerve - from anterior ramus division of C2
What innervates the occipital region skin?
Greater occipital nerve - from posterior ramus of C2
What does the great auricular nerve supply?
skin posterior to the ear and over the angle of the mandible
Where does the great auricular nerve derive from?
Anterior rami of C2 & C3
What does the Third Occipital Nerve supply?
Skin of the inferior occipital region
Where does the third occipital nerve derive from?
posterior ramus of C3
What muscle prevents closure of bleeding vessels and surrounding skin in a scalp laceration?
Occipitofrontalis muscle
What 3 bones make up the anterior cranial fossa?
Frontal Bone
Ethmoid Bone
Sphenoid Bone
What makes up the floor of the anterior cranial fossa?
frontal bone, ethmoid bone and the anterior aspects of the body and lesser wings of the sphenoid bone
Where does the falx cerebri attach to?
Frontal crest - midline ridge of the frontal bone
and
Crista galli of the ethmoid bone
What is either side of the crista galli?
Cribriform plate
What is the role of the cribriform plate?
Supports olfactory bulb and has foramina that can transmit vessels and nerves
Where are the anterior ethmoidal foramen and posterior ethmoidal foramen?
Larger foramina on the cribriform plate on the ethmoid bone
What travels through the anterior ethmoidal foramen?
Anterior ethmoidal artery, nerve, vein
What travels through the posterior ethmoidal foramen?
posterior ethmoidal artery, nerve and vein
What is the thinnest part of the anterior cranial fossa?
Cribriform Plate
What are the consequences of a cribriform plate fracture?
- Anosmia - olfactory nerves can be sheared and therefore loss of sense of smell
- CSF rhinorrhoea - fracture can tear the meningeal covering of the brain causing CSP leak = clear fluid from nasal cavity
What does the anterior cranial fossa contain?
anteroinferior portions of the frontal lobe
What does the middle cranial fossa contain?
pituitary gland
temporal lobes
What bones make up the middle cranial fossa?
Sphenoid
Temporal bones
What is the saddle shaped bony prominence that supports the pituitary gland and where is it?
Sella turcica
in the Middle Cranial Fossa
What are the 3 parts of the sella turcica?
- tuberculum sellae
- hypophysial fossa / pituitary fssa
- dorsum sellae
What are the main foramina of the sphenoid bone in the middle cranial fossa?
- optic canals
- superior orbital fissure
- foramen rotundum
- foramen ovale
- foramen spinosum
What travels through the optic canals?
- Optic Nerves (CN II)
- Ophthalmic arteries
What travels through the superior orbital fissure?
- Oculomotor nerve (CN III)
- Trochlear nerve (CN IV)
- ophthalmic branch of the trigeminal nerve (CN V1)
- Abducens nerve (CN VI)
- ophthalmic veins and sympathetic fibres
What travels through the foramen rotundum?
- maxillary branch of the trigeminal nerve (CN V2)
What travels through the foramen ovale?
- mandibular branch of the trigeminal nerve (CN V3)
- accessory meningeal artery
What travels through the foramen spinosum?
- Middle meningeal artery
- middle meningeal vein
- meningeal branch of CN V3
What are the main foramina of the temporal bone in the middle cranial fossa?
- Hiatus of the greater petrosal nerve
- hiatus of the lesser petrosal nerve
- Carotid Canal
What travels through the hiatus of the greater petrosal nerve?
- greater petrosal nerve (branch of the facial nerve)
- petrosal branch of the middle meningeal artery
What travels through the hiatus of the lesser petrosal nerve?
- lesser petrosal nerve - branch of the glossopharyngeal nerve
What travels through the carotid canal?
- Internal carotid artery
- deep petrosal nerve
What is in the posterior cranial fossa?
brainstem and cerebellum
What bones make up the posterior cranial fossa?
- occipital bone
- two temporal bones
What is the anteromedial border of the posterior cranial fossa?
dorsum sellae of the sphenoid bone
What is the anterolateral border of the posterior cranial nerve?
superior border of the petrous part of the temporal bone
What is the posterior border of the posterior cranial fossa?
internal surface of the squamous part of the occipital bone
What is the floor of the posterior cranial fossa made of?
mastoid part of the temporal bone
squamous, condylar and basilar parts of the occipital bone
What parts make up the brainstem?
Medulla oblogata
pons
midbrain
What travels through the internal acoustic meatus?
- Facial nerve (CN VII)
- Vestibulocochlear nerve (CN VIII)
- Labyrinthine artery
What are the main foramina in the posterior cranial fossa?
- Internal acoustic meatus - temporal bone
- foramen magnum - occipital bone
- jugular foramina - occipital bone
- hypoglossal canal - occipital bone
What travels through the foramen magnum?
- medulla
- meninges
- vertebral arteries
- ascending spinal accessory nerve
- dural veins
- anterior and posterior spinal arteries
What travels through the jugular foramina?
- glossopharyngeal nerve
- vagus nerve
- descending spinal accessory nerve
- internal jugular vein
- inferior petrosal sinus
- sigmoid sinus
- meningeal branches of the ascending pharyngeal and occipital arteries
What travels through the hypoglossal canal?
- hypoglossal nerve
What is MacEwen’s Triangle or supra meatal triangle?
Mastoid Fossa - bony landmark of the temporal bone
What is the relevance of the mastoid fossa?
Important anatomical landmark in otologic surgery
What is the superior border of the mastoid fossa?
Supramastoid crest - extension of the upper border of the posterior root of the zygomatic process
What is the anterior border of the mastoid fossa?
Suprameatal Spine (Spine of Henle) - projection of bone at posterosuperior aspect of the opening of the external acoustic meatus
What is the posterior border of the mastoid fossa?
Hypothetical vertical line that is tangential to the mid-point of the posterior wall of the external auditory canal
What is the ‘safe area’ for beginning the drilling approach during a cortical mastoidectomy?
mastoid fossa/MacEwen’s triangle - no structures other than mastoid antrum underneath
What is a cortical mastoidectomy for?
It’s the removal of mastoid air cells especially for severe acute mastoiditis
Where is the infratemporal fossa located?
base of skull, deep to masseter muscle
What other fossae is the infratemporal fossa closely related to?
pterygopalatine fossa
temporal fossa
What is the lateral boundary of the infratemporal fossa?
condylar process and ramus of the mandible bone
What is the Medial border of the infratemporal fossa?
lateral pterygoid plate, tensor veli palatine, levator veli palatine and superior constrictor muscles
What is the Anterior border of the infratemporal fossa?
posterior border of the maxillary sinus
What is the Posterior border of the infratemporal fossa?
carotid sheath
What is the roof of the infratemporal fossa?
greater wing of the sphenoid bone
What is the floor of the infratemporal fossa?
medial pterygoid muscle
What muscles are located inside the infratemporal fossa?
medial and lateral pterygoids
What muscles insert/originate into the borders of the infratemporal fossa?
masseter and temporalis muscles
What nerves pass through the infratemporal fossa?
- Mandibular nerve - branch of trigeminal CN V - motor and sensory
- Auriculotemporal, buccal, lingual, inferior alveolar nerves - sensory branches of trigeminal
- Chorda tympani - facial nerve CN VII branch
- Otic ganglion - parasympathetic neurone cell bodies
What vasculature is contained in the infratemporal fossa?
- Maxillary artery - terminal branch of external carotid - then gives rise to middle meningeal artery as it passes through
- Pterygoid venous plexus
- Maxillary vein
- Middle meningeal vein
What structure could be damaged by a punch to the side of the skull?
the pterion
What is the Pterion?
It’s the point where temporal, patietal, frontal and sphenoid bones meet
What can happen if you fracture the pterion?
Trauma can damage the MMA, causing raised ICP
What virus commonly causes infectious mononucleosis (glandular fever)?
Epstein-Barr virus
What is Epstein-Barr associated with?
Infectious mononucleosis
Burkitt’s lymphoma
Nasopharyngeal carcinoma
Autoimmune diseases - SLE
What is the classical triad of infectious mononucleosis?
fever
pharyngitis
lymphadenopathy
What imaging needs to be done for infectious mononucleosis?
USS Abdo - splenomegaly (consideration for contact sport)
CT abdo - if concerned re: splenic rupture
How long post infection with EBV would you expect to see VCA-IgM (viral capsid antigens) for?
3-4 months
When do you expect to see VCA-IgG (viral capsid antigen) post EBV infection?
first detected at 2-4 weeks post infection and persist for life
Approx what distance is the duodenal papilla from the pylorus?
7-10 cm
What is the pathophysiology of aortic dissection?
1st - tear in tunica intima of aorta
2nd - degeneration of tunica media, blood tracks & causes false lumen
3rd -false lumen can occlude aortic branches
4th - blood vessel occlusion & change of blood flow = symptoms
What are the two types of classification system for an aortic dissection?
De Bakey (I-III) and Stanford (A & B)
Which classification of aortic dissection do you definitely surgically repair?
De Bakey I & II, Stanford A
What are the De Bakey Classifications?
I - intima tear @ ascending aorta and dissection affects descending aorta or abdo aorta
II - dissection in the ascending aorta
III - dissection in the descending aorta and propagates distally
What are the Stanford Classifications?
A - dissection in ascending aorta +/- aortic arch involvement +/- descending aorta involvement
B - dissection in descending aorta not affecting ascending aorta
What hormonal therapy can be used for carcinoid (neuroendocrine) tumours?
somatostatin analogues - octreotide or lanreotide
What hormonal therapy can be used for endometrial carcinomas?
Progestins
What hormonal therapy can be used for pheochromocytomas?
phenoxybenzamine - blocks alpha receptors
What hormonal therapy can be used for pre-menopausal ER +ve breast cancers?
tamoxifen - oestrogen antagonist
What hormonal therapy can be used for post-menopausal ER +ve breast cancers?
aromatase inhibitors - anastrozole, letrozole, exemestane
What hormonal therapy can be used for prostatic carcinomas?
Gonadotrophin-releasing hormone analogues - goserelin & buserelin
What is the blood supply to the ureter?
Upper part - renal artery
Middle - abdominal aorta
Lower - internal iliac arteries
What structures are in the renal hilum posterior to anterior?
Renal pelvis - most posterior
Renal artery
Renal vein - most anterior
What hormones & enzymes do the kidneys produce?
Erythropoietin
Renin
1,25-dihydroxyvitamin D
What level does the ureter arise at?
L2
What is the path of the ureter?
- Arises at L2
- Descends anteriorly to psoas major, adjacent to transverse processes of lx spine
- Crosses bifurcation of common iliac artery at roughly SIJ level
- Travels under uterine artery or vascular deferens
- Enters bladder at level of ischial spines
What is the innervation of the ureter?
Ureteric plexus & sensation are from T12-L2
Pain refers to those dermatomes
What surface of the bladder is covered by peritoneum?
Only superior surface
What causes the detrusor muscle to relax/contract?
Autonomic nervous system
Parasympathetic = contract and urination - pelvic nerve S2-4 act on muscarinic (M3) receptors
Sympathetic = relaxation and urine storage - inferior hypogastric plexus T12-L2 act on adrenergic beta receptors
What extra urethral sphincter do men have?
Internal urethral sphincter
What are the 3 layers of the detrusor muscle?
Inner longitudinal
Middle circular
Outer longitudinal
What causes the external urethral sphincter to relax/contract?
Conscious control - somatic
Pudendal nerve S2-4 on nicotinic receptors
What causes the external urethral sphincter to relax/contract?
Conscious control - somatic
Pudendal nerve S2-4 on nicotinic receptors
Blood supply to AV node
Right coronary artery
Define expiratory reserve volume
Additional amount of air that can be exhaled after normal exhalation
Ductus venosus function
Shunt between umbilical vein and IVC
Delivers oxygenated blood from placenta to heart
Closes and becomes ligamentum venosum on underside of live
Commonest cause of osteomyelitis in non-sickle cell patient
Staph aureus
Define inspiratory reserve volume
Max vol of air that can be inspired in excess of normal inspiration
Which part of nephron is impermeable to water
Ascending loop of Henle
Useful landmark for femoral artery
Mid-inguinal point
Common cause of narrow anion gap metabolic acidosis
Type 1 renal tubular acidosis
Locations of ectopic testis
Perineal
Superficial inguinal.pouch
Femoral canal
Pre-penile
Superficial peroneal nerve supplies
Muscles of lateral compartment - eversion
Cutaneous sensation to foot dorsum except 1st dorsal Web space
Deep peroneal nerve
Muscles of anterior compartment
Sensation to 1st webbed space
Pharyngeal pouch
Defect between thyropharyngeus and cricopharyngeus
Killans dehiscence
MOA aliskiren
Direct renin inhibitors
For me of essential hypertension
Where is stellate ganglion located?
Between T1 and C8
Damage to stellate ganglion causes
Horners Syndrome
Causes of horners
Apical lung tumours (pancost)
First rib #
UL injury - klumpskes
Diaphragm insertion
Central tendon
Level abdominal.aorta passes through diaphragm
T12
IVC goes through diaphragm.
T8
Level oesophagus passes through diaphragm.
T10
Bleeding in clavicopectoral fascia is caused by which artery
Thoraco-acromial artery
Which is the commonest site of obstruction in cerebrospinal fluid flow
Cerebral aqueduct of sylvius
ACID –> EGGT hypersensitivity reaction
- A -Atopy/anaphylactic - IgE
- C - Cyto - IgG
- I - Immune - G
- D - delayed T cells
Primary metabolic effect of adrenaline
Glycolysis
Primary metabolic effect of adrenaline
Glycolysis
What forms tendinous part of diaphragm?
Septum transversum
What forms muscular part of diaphragm?
2 pleural peritoneal membranes and peripheral body wall muscle
What forms the crura of the diaphragm?
Mesentery of oesophagus
Structures passing diaphragm at T8
IVC
Right phrenic
Structures passing through diaphragm T10
Oesophagus
Vagus nerve
Structures passing through the diaphragm at T12
Abdo aorta
Thoracic duct
What are Aschoff-Rokitansky sinuses associated with?
Chronic cholecystitis
Annular pancreas
Embryology anomaly
Duodenal obstruction
2nd part of duodenum is completely/incompletely encased by the pancreas
Narrowing and dilation of prox dueodenum
Becks triad for tamponade
Hypotension
Muffled heart sounds
Distended neck veins
Nasolacrimal duct drains into…
Inferior meatus
What hormone is responsible for hydroxylation for vit D3?
PTH
levator ani muscles
Pubococcygeus
Puborectalis
Ileococcygeus
TFTs for Graves
Decreased TSH
Raised T4 and T3
S&S of small bowel atresia
Neonate
Bilious vomiting
Passed meconium but nothing since
Abdo distension
Dilated bowel loops on AXR
MOA UV light on micro organisms
Forms pyrimidine dimers and alter form of DNA and interfere with normal base pairing during DNA synthesis
Takayasu’s arthritis
Large vessel inflammatory vasculitis affecting aorta & branches
Women over 40
Which factor is involved in extrinsic coag cascade
7
Brain cyst after infarction caused by
Liquidative necrosis
Most characteristic histological feature of invasive ductal carcinoma
Pleomorphism
Atypical ductal cells
Most characteristic histological feature of invasive ductal carcinoma
Pleomorphism
Atypical ductal cells
Practical treatment for hereditary angio-oedema
FFP
Ideally you need recombinant C1 esterase inhibitor but this is often not immediately available
Common organism for fourniers gangrene
Mixed flora
Most likely complication of chronic suppurative otitis media
Lateral sinus thrombosis
Formation of male external genitalia requires
Dihydrotestosterone
Vessel anterior to medial malleolus
Great saphenous vein
Cervix lymph drainage
Internal iliac lymph nodes
What activates classical complement pathway?
Immunoglobulins
SMA passes posterior to what?
Splenic vein
Neck of pancreas
Staghorn calculi
Recurrent UTIs
Urease producing bacteria
Struvite or calcium carbonate
Radio-opaque
Partial rectal prolapse in kids mx
Most resolve with Conservative management
Portal vein formed by
Splenic and SMV
Parasympathetic nerve fibres leave CNS
CN 3, 7, 9, 10
2nd, 3rd, 4th sacral segments of spinal cord
What sits in the superficial perineal space in males?
Corpus spongiosum
What drains the anterior region of the heart?
Great cardiac vein
Where does the great cardiac vein run down?
Anterior interventricular groove
Stab wound just below right nipple will damage what?
Pulmonary trunk
Other middle mediastinal contents
Primary structure forming posterior wall of inguinal canal
Conjoint tendon
Role of pneumotaxic centre
Upper part of pons
Controls rate and pattern of breathing
Regulates amount of air that can be taken into each breath
Number of secondary ossification centres between C3-L5
5