Anatomy Flashcards
Phrenic Nerve
C3,4,5, anterior to lung root, on scalenus anterior, b/w subclavian artery and vein, pierces diaphragm
Vagus Nerve
C X, posterior to lung root, alongside trachea, anterior oesophegus
Fusiform Aneurysm
Dilation of both sides
Saccular Aneurysm
Dilation of one side
Pericardium Location (& anterior mediastinum)
1-4 sternebrae, T5-T8 vertebrae
Inferior mediastinum
T5-T12
Ligamentum Arteriosum
Fibrus band remenant of ductus arteriosus
Vertebrae
7 Cervical - typical & atypical - foramen in transverse processes 12 Thoracic - costal facets for ribs - articular processes in coronal plane 5 Lumbar - articular processes in saggital(ish) plane 5 Sacral (fused) 2-5 Coccyx
Trachea
Begins at C6
Bifurcates at T4/5
Pain referred from lungs and pleura
Visceral = shares AUTONOMIC NERVE SUPPLY of heart and lungs. Pain referred is DULL, NOT SEVERE, POORLY LOCATED.
Parietal = shares SOMATIC NERVE SUPPLY of diaphragm, ribs, intercostals. Pain referred is SHARP, SEVER, WELL LOCATED.
Chest X Ray technique
Full inspiration (7 ribs anterior, 11 ribs posterior)
Posterior to Anterior
‘hug x-ray’ - rotate scapulae
Erect
Check vertebrae is straight (spinous processes)
Airway features
Trachea
Bronchi
Bronchioles
Trachea
- hyaline C shaped cartilages (in adventitia) with muscle bridge
- submucosa contains glandular structures
Bronchi
- cartilage plates
- smooth muscle complete ring between lamina propria and submucosa
Bronchioles
- no cartilage
- loses goblet cells, gains clara cells
- has some smooth muscle
External Oblique
“front pockets”
anterior surface of lower 8 ribs
free posterior muscular edge
interdigitate in vertical raphe (aponeurotic)
free inferior edge
ASIS (anterior superior iliac spine) -> pubic tubercle
Δ opening between pub tub & pub crest
Internal Oblique
“back pockets”
attach to costal margin
attach to thorocolumbar fascia posteriorly
aponeurotic medially
anterior 2/3 of inguinal ligament -> pub crest
TVA
horizontal
underlap costal margin, continuous with plane of diaphragm
attach to thorocolumbar fascia
attach to midline raphe (linea alba)
lateral 1/2 inguinal ligament -> pub crest
Rectus Abdominus
vertical, tendinous inscription (umbilicus, xyphisternum, 1/2 way between)
anterior surface of ribs 5,6,7
linear semilunaris (lateral border)
linea alba medially
insert pubic crest
posterior sheath ceases at arcuate line (TVA + int oblq become anterior)
Nerves of anterior abdominal wall
T10 - umbilicus
L1 - groin
Arteries of anterior abdominal wall
superior epigastric - branch of internal thoracic - anastamose posterior rectus sheath inferior epigastric - branch of internal iliac superficial epigastric - in superficial fascia
Veins of abdominal wall
dual veinous drainage
- portal
- IVC
Inguinal Canal
DEEP RING: deficiency in transcersalis half way between ASIS & pub tubercle
4cm long
parallel to inguinal ligament
roof is arching fibres of internal oblique & TVA
Inguinal Canal Layers
- Internal Spermatic Fascia (transversalis fascia)
- Cremasteric Fascia (has muscle to retract testicle - internal oblique)
- External Spermatic Fascia
Quadratus Lumborum
tip of transverse processes, 12th rib, iliac crest
kidneys lay on top (anterior)
Psoas
inferior border of T12 to upper border of L5
attaches to medial ends of transverse processes
lumbar arteries & veins behind
lumbar plexus within
sympathetic trunk anterior
insertion on lesser trochanter (shared with iliacus)
Kidneys
T12 - L3
right sits lower than left
adrenals (right pyramid, left crescent)
hilum (artery, vein, pelvis) faces anteromedially
cortex (outer, pale striated)
medulla (discontinuous, darkened)
minor calyces (2-3) -> major calyces (3) -> pelvis -> ureter
left renal vein under superior mesenteric artery
5 artery segments
Ureter
descend on posterior abdominal wall on psoas parallel to tips of transverse processes over pelvic brim cross over common iliac artery and vein below uterine artery / vas deferens bladder
3 sites that can become obstructed by kidney stones
- narrowing renal pelvis -> ureter
- compression ureter over pelvic brim (mid ureter)
- narrowing ureter -> bladder
Abdominal Vessels (3 branches)
aorta bifuricates at L4 (into common iliac arteries)
three vascular planes
1. anterior branch (coeliac trunk, superior/inferior mesenteric)
2. lateral branches (kidneys)
3. posterior branches (intercostals/obliques)
Foregut
start at abdominal oesophegus
ends at duodenal papilla (1/2 way down 2nd part of duodenum on posteromedial wall)
supplied by coeliac trunk?
Preganglionic Sympathetic T6-T9 (&afferent)
Parasympathetic - Vagus
Midgut
unclear demarcation
include most of transverse colon (to short splenic flexture)
supplied by superior mesenteric?
Preganglionic Sympathetic T8-T12 (&afferent)
Parasympathetic - Vagus
Hindgut
descending and sigmoid colon and rectum
supplied by inferior mesenteric?
Preganglionic Sympathetic T12-L2
Parasympathetic - Pelvic Splanchnics S2-S4
(afferents sympathetic until sigmoid, then parasympathetic)
Abdominal Vessel Names & Locations
COELIAC TRUNK - T12
- Splenic Artery (pancreas, upper greater curvature - left gastroepiploic artery)
- Common hepatic (proper hepatic, right gastric, pancreaticoduodenal/gastroduodenal)
- Left gastric (lesser curvature)
SUPERIOR MESENTERIC - L1
- (jejunum) long vasa rectae, few vascular arcades
- (ilium) short vasa rectae, many vascular arcades
- right colic (supplies ascending colon)
- middle colic (supplies transverse colon)
INFERIOR MESENTERIC - L3
- left colic (descending colon)
SUPERIOR RECTAL ARTERY
- passes into pelvis
Portal Venous Drainage
Portal vein low pressure and valveless
Behind neck of pancreas at level of L2
Left gastric vein can drain to azygous.
Superficial abdominal wall veins anastomose with portal vein tributaries.
Rectal veins anastamose. Portal hypertension can present as haemorrhoids.
Abdominal Lymphatics
Pre-Aortic (anterior)
- around unpaired three branches; liver, pancreas, gallbladder, spleen (coeliac, inferior/superior mesenteric)
Para-Aortic (side)
- from posterior wall, kindeys, adrenals, testes, ovaries, pelvis and lower limb
Trunks
- intestinal (from pre-aortic lymph nodes)
- right & left lumbar lymph trunks
- Coalesce to form CISTERNA CHYLI (adjacent to aortic hiatus)
X-Ray absorption factors
- THICKNESS of tissue
- DENSITY of tissue
- ATOMIC number of tissue (to 4th power)
H = 1
C = 6
O = 8
Ca = 20
Io = 53
Ba = 56
Abdominal X-Ray Contrast Techniques
Endoscopic Retrograde Cholangio-pancreatography
(inject iodine into bile duct - endoscopically)
Percutaneous Transhepatic Cholangiography
(inject into bile duct - through abdominal wall)
Intravascular
(distribution through blood vessels, excretion by kidney)
(bilirubin like tagging for excretion into bile duct)
Radioisotope Imaging
Emit gamma rays (recorded by gamma camera)
MRI
Alters H+ spin (tissue must have water)
0.3 - 3.0 Tesla
Good spacial and contrast resolution Good for soft tissue (brain) and bone marrow Bad for bones (low H+ appears black) Good for inside joints Availability variable Contraindications (pacemaker, cochlear implant etc.) More Expensive Long Scan Times
GI sacks
Lesser Sack (Foramen of Winslow) - hangs over transverse colon and fuses to form greater omentum
pocket with pancreas posterior and stomach/lesser omentum anterior
Liver
- blood supply
- segment
75% Portal Vein
25% Hepatic Artery
Falciform ligament demarcates left and right anatomically
IVC-Gallbladder demarcates left and right physiologically
Caudate lobe (fissure/IVC/hilum)
Quadrate lobe (fissure/Gallbladder/hilum)
Falciform -> ligamentum teres -> umbilical
ligamentum venosum - shunt to IVC bypassing liver in foetus
Abdominal Viscera Layers
Layer 1: Paired Viscera - retroperitoneal
= kidneys/ureter
Layer 2: Unpaired Viscera - retroperitoneal
= ascending & descending colon
= duodenum
= pancreas
Layer 3: Intraperitoneal Unpaired Viscera
= mesogastrum / stomach
= mesentery / jejunum/ilieum
= transverse mesocolon
Pancreas
- structure
- functions
- histology
retroperitoneal
head (uncinate process), neck, body, tail
principal & accessory pancreatic duct
EXOCRINE:
enzymes for digestion (protein, starches, fat)
- proteases
- amylases
- nucleases
bicarbonate
ACINI with basal RER, luminal ZYMOGEN GRANULES
ENDOCRINE: insulin glucagon somatostatins ISLETS OF LANGERHANS, vascular, pale pink
Spleen
Highly vascular LUQ notched smooth diaphragmatic surface axis lies along shaft of 10th rib thin capsule (trauma can rupture spleen)
Hepatocytes, Liver, and Models
Hepatocytes
RER, Golgi = protein synthesis
SER = fat & steroid metabolism
Hepatocytes organised in LOBULES supported by Reticular fibres
- Central vein (sinusoids)
- Portal Triads (hepatic artery, portal vein, bile duct [canaliculi], lymphatic)
Sinusoids:
- Discontinous lining
- gap between endothelium and hepatocyte = SPACE OF DISSE
- KUPFER CELLS (macrophages) on inner walls
- Classic Lobule Model (central vein)
- Portal Lobule Model (portal triad)
- Acinar Model (O2 conc. gradients)
Synovial Joint Structures
- Articular (hyaline) Cartilage - aneural, avascular
- Fibrous Capsule - collagen, elastin, fibroblasts
- Intrinsic Ligaments
- Extrinsic Ligaments
- Synovial Membrane - highly vascular
Ligaments typically have poor blood supply and don’t repair very rapidly
Special Joint Structures Labrum Fat Pad Disc Menisci Bursae Ligament Tendon
Labrum - fibrocartilaginous rim deepening joint
Fat Pad - within joint, external to membrane
Disc / Menisci - shock absorb, bear weight, blood & nerve supply to outer third
Bursae - contain synovial fluid and communicates with joint
Ligament - thickening of capsule (intrinsic of extrinsic)
Tendon (intracapsular) - labrum provide joining site
Shoulder (glenohumeral) Anatomy (Layers)
- Bones (glenoid fossa of scapula)
- Labrum
- Capsule (reinforced by intrinsic ligaments)
- attach to anatomical neck above
- attach to surgical neck below
- anterior deficiencies for bicep long head and bursa (subscapular) - Tendons (rotator cuff - originate from scapula and insert into capsule)
- infraspinatus: external rotation
- subscapularis: internal rotation
- supraspinatus: abduction (+ deltoid) - Coraco-acromial ligament/arch & sub-acromial bursa
Humerous Anatomical Features
Greater & Lesser tuberosities (anterior / superior)
Bicipital groove in between for bicep long head
Surgical neck - endangers axilliary nerve
mid-shaft - endangers radial nerve (in groove)
supracondylar - endangers median nerve & brachial artery
Condyles (capitulum anteromedial, trochlea anterolateral)
Epicondyles
Clavicle Anatomical Featues
Medial 2/3 curve anteriorly
Lateral 1/3 curve posteriorly
Articulates with scapula
Sternoclavicular Joint
- tight capsule
- disc (outer 1/3 has nerve and blood supply)
- costoclavicular acessory ligament (attach to superior medial surface of first rib)
- subluxation rare - endanger subclavian vein & artery
Acromioclavicular Joint
- plane synovial joint in saggital plane
- weak capsule
- coracoclavicular lig. (conoid, trapezoid) main stabilizer
- subluxation (Grade 1-3)
Radius & Ulna Anatomical Features
Share synovial cavity at elbow
Radius articulates with lateral side of ulna
Radius processes (coronoid anterior, olecranon posterior)
Elbow Joint Complex
- Ligaments
- other
LIGAMENTS:
- Medial Collateral Ligament (attaches to medial epicondyle)
- Lateral Collateral Ligament (attaches to lateral epicondyle)
- Annular ligament (encloses head of radius allowing rotation and provides point of attachment for LCL)
OTHER:
Intracapsular fat pads fill fossae
Olecranon bursa
Most stable in extension
Muscles of forearm
PRONATION/SUPINATION
Pronator teres
supinator
pronator quadratus
FLEXION/EXTENSION (also enhance stability of carpals)
extensor carpi radialis brevis (wrist extensor originating from lateral epicondyle)
flexor carpi radialis
Wrist / Hand bones
- Proximal (lateral to medial)
- Distal (lateral to medial)
Some Lovers Try Positions That They Can’t Handle
S L Tri P Trai Trao C H
Scaphoid (most frequently fractured - at waist)
Lunate (most frequently subluxed)
Triquetral
Pisiform (sesamoid bone in tendon - flexor carpi ulnaris, ossifies at 11/12yo)
Trapezium
Trapezoid
Capitate (largest, first to ossify at 2 years)
Hamate (with hook)
Metacarpals - sesamoid on 1st distally Phalanges - proximal - middle -distal
Wrist Ligaments
Palmar-radio-carpal ligaments - prevent carpals from sliding medially (moreso than dorsal)
- transmit vessels to carpal bones
Radio-scapho-lunate ligament - keeps scaphoid and lunate in position
Deep transverse metacarpal ligament (holds 4 metacarpals together - but not thumb)
Structures of fingers
- Ligaments
- Plates
I Carpometacarpal - Saddle II-III Carpometacarpal - Immobile IV-V Carpometacarpal - Hinge (f/e) Metocarpophalangeal - Condyloid Joints Volar & Dorsal Plates (extend surface area for articulation - site of pathology)
Wrist Joints
Radiocarpal - synovial ellipsoid
- scaphoid (medial/lateral)
- lunate (anterior/posterior)
- F>E, UD>RD
Intercarpal (midcarpal) - condylar
- E>F
- RD>UD
- flexion / extension
- radial / ulnar deviation
Rule of deep muscles
Arise from shaft of long bone that they overlie (and adjacent interosseous membrane)
Rule of superficial muscles
proximal origin, distal insertion
Muscles involved in wrist radial deviation
Extensor carpi radialis longus
Extensor carpi radialis brevis
Flexor carpi radialis
Muscles involved in wrist unlar deviation
Flexor carpi ulnaris
Extensor carpi ulnaris
Radiolucent
Dark structures on XRay
Radio-opaque
Light structures on XRay
T1 vs T2 MRI Imaging Signal Intensity
T1 WEIGHTED Fluid - Dark Fat - Bright Muscle - Intermediate Spinal Cord - Intermediate Cortical Bone - Very Dark Flowing Blood - Dark
T2 WEIGHTED Fluid - Bright Fat - Intermediate to Bright Muscle - Intermediate Spinal Cord - Intermediate Cortical Bone - Very Dark Flowing Blood - Dark
can use fat suppression to darken fat
Age of Elbow Epiphyses Appearance
1st year - Capitulum (+ lat trochlear)
5th year - Medial epicondyle & Radial head
10th year - Trochlear (medial), lat epicondyle, olecranon
Medial and lat epicondyle, radial head, olecranon fuse between 15-20
Muscles attaching pectoral girdle to trunk
THORACIC WALL: Pectoralis Major Pectoralis Minor Subclavius Serratus Anterior
VERTEBRAL COLUMN Trapezium Latissimus Dorsi Levator Scapulae Rhomboid Minor Rhomboid Major
Subclavius
ORIGIN: Anteromedial part of first rib
INSERTION: Inferior surface of clavicle
Stabilizes clavicle
Pectoralis Minor
ORIGIN: costal cartilage ribs 3,4,5
INSERTION: converge on coracoid process
Stabilizes scapula
Serratus Anterior
ORIGIN: lateral aspect of ribs 1-8
INSERTION: medial border of scapula
INNERVATION: long thoracic nerve
Strong protractor
Muscles attaching at humerus to scapula / rotator cuff
Deltoid Subscapularis* Supraspinatus* Infraspinatus* Teres Minor* Teres Major
- rotator cuff muscles
Supraspinatus
ORIGIN: Supraspinatus Fossa
INSERTION: Superior facet on greater tubercle of humerus
Infraspinatus
ORIGIN: Infraspinatus fossa (posterior)
INSERTION: middle facet on greater tubercle of humerus
Teres Minor
ORIGIN: lateral border of the scapula
INSERTION: inferior facet on greater tubercle of humerus
Deltoid
ORIGIN:
INSERTION:
Abductor (need supraspinatus to initiate)
Subscapularis
ORIGIN: subscapular fossa (anterior)
INSERTION: lesser tubercle of humerus
Teres Major
ORIGIN: inferior angle of scapula (bottom of triangle)
INSERTION: proximal humerus just below lesser tubercle
Adducts and medially rotates
Muscles of Upper Arm
ANTERIOR:
Coracobrachialis
Biceps
Brachialis
POSTERIOR:
Triceps
Biceps
ORIGIN: supraglenoid tubercle (long head through bicipital groove), coracoid process (short head)
INSERTION: radial tuberosity
Flexor (in supination) and primary supinator
Coracobrachialis
ORIGIN: coracoid process
INSERTION: mid-shaft of humerus
Assists in flexion and adduction of shoulder
Brachialis
ORIGIN: whole of anterior aspect of distal humerus
INSERTION: coronoid process of ulna
flexor of elbow joint (in all position)
Rule for Deep Muscles
Arise from shaft of long bone they overly (and adjacent interosseous membrane)
Triceps
ORIGIN: infraglenoid tubercle (long head), proximal aspect of posterior shaft of humerus (lateral head), shaft of posterior humerus (medial)
INSERTION: olecranon of ulna
Muscles of Forearm - Anterior
SUPERFICIAL Pronator Teres Flexor Carpi Radialis Palmaris Longus Flexor Digitrum superficialis Flexor Carpi Ulnaris (all attach to common flexor origin: front of medial epicondyle)
DEEP
Flexor pollicis longus
Flexor digitorum profundus
Pronator Quadratus
Muscles of Forearm - Posterior
SUPERFICIAL
Brachioradialis
Extensor Carpi Radialis Longus
Extensor Carpi Radialis Brevis*
Extensor Digitorum*
Extensor Digitorum minimi*
Extensor Carpi Ulnaris*
Abductor Pollicis Longus
Extensor Polllicis Brevis
Extensor Pollicis Longus
DEEP:
Aconeus
Supinator
Extensor Indicis
*arise from common extensor origin (lateral epicondyle)
Flexor Carpi Radialis (FCR)
ORIGIN: Common Flexor Origin
INSERTION: base of 2nd and 3rd metacarpals
has separate tunnel to Carpal Tunnel
Palmaris Longus
ORIGIN: Common Flexor Origin
INSERTION: blends with flexor retinaculum and palmar aponeurosis
absent in 10% of people
Flexor Carpi Ulnaris (FCU)
ORIGIN: Common Flexor Origin AND wide aponeurotic attachment to subcutaneous border of ulna
INSERTION: base of 5th metacarpal*
* actually inserts on pisiform which gives rise to pisometacarpal ligament
Pronator Quadratus
ORIGIN/INSERTION: across distal portions of anterior aspect of shaft of radius and ulna
Pronator Teres
ORIGIN: Common Flexor Origin AND medial aspect of coronoid process
INSERTION: point of greatest convexity on radius
Flexor Digitorum Superficialis (FDS)
ORIGIN: Common Flexor Origin (humeral-ulnar head) AND fibrous arch to radius
INSERTION: 4 tendons inserting on base either side of middle phalynx
*girly fist
Flexor Digitorum Profundus (FDP)
ORIGIN: Shaft of ulna and adjacent interosseous membrane
INSERTION: 4 tendons inserting on base of distal phalynx
*proper fist
Flexor Pollicis Longus
ORIGIN: shaft of radius and adjacent interosseous membrane
INSERTION: base of distal phalynx (thumb)
Thumb version of FDP
Flexor Retinaculum
STOP Scaphoid Trapezium hook Of hamate Pisiform
Tunnel Contents: Palm to Deep
FDS 3,4
FDS 2,5
FDP
median nerve lateral
Flexor Pollicis Longus more lateral
Brachioradialis
ORIGIN: lateral supracondylar ridge (above common extensor origin)
INSERTION: styloid process of radius (distal)
Extensor Carpi Radialis Longus
ORIGIN: lateral supraconylar ridge (above common extensor origin)
INSERTION: base of 2nd and 3rd metacarpals posteriorly
Extensor Carpi Radialis Brevis
ORIGIN: Common Extensor Origin
INSERTION: base of 2nd and 3rd metacarpals posteriorly
Extensor Digitorum
ORIGIN: Common Extensor Origin
INSERTION: 4 tendons inserting base of middle and distal phalynx (like FDS and FDP)
Also tendinous communications between digits
Extensor Digiti Minimi
ORIGIN: Common Extensor Origin
INSERTION: 5th middle and distal phalynx (merge with extensor digitorum)
Extensor Carpi Ulnaris
ORIGIN: Common Extensor Origin
INSERTION: base of 5th metacarpal
Abductor Pollicis Longus
ORIGIN: Posterior aspect of radius, ulna, and interosseous membrane
INSERTION: base of first metacarpal
Extensor Pollicis Brevis
ORIGIN: Posterior aspect of radius, ulna, and interosseous membrane
INSERTION: base of proximal phalynx
Extensor Pollicis Longus
ORIGIN: Posterior aspect of radius, ulna, and interosseous membrane
INSERTION: base of distal phalynx
Anconeus
ORIGIN: Common Extensor Origin
INSERTION: posterior aspect of proximal ulna
small triangular muscle
Supinator
Encircles and obscures view of proximal shaft of radius
Has superficial and deep heads which is the passage for nerve supply to enter posterior compartment
Extensor Indicis
Extensor of index finger (not a major player in pathology)
Extensor Retinaculum
Vertical Septa separate tendons into 6 compartments numbered lateral to medial
Layers of Palm
- Skin and palmaris brevis
- Palmar aponeurosis*
- Thenar and hypothenar muscles
- Neurovascular plane
- Long flexor tendons^ and lumbricals
- Adductor pollicis and neurovascular plane
- Interossei and metacarpals
*does not cover layer 3 muscles. Inserts into skin creases at base of fingers, flexor tendons, and bases of proximal phalanges.
^ synovial sheath for middle three fingers ends just distal to flexor retinaculum and starts again as separate sheath lining fibrous sheath over phalanges
Intrinsic Muscles of the Hand (Anterior)
All For One
And
One For All
Abductor Pollicis Brevis
Flexor Pollicis Brevis
Opponens Pollicis
Adductor Pollicis Brevis
Opponens Digiti Minimi
Flexor Digiti Minimi
Abductor Digiti Minimi
All arise from flexor retinaculum and adjacent carpal bones
Adductor pollicis Brevis arises from shaft of 3rd metacarpal and base of 2nd and 3rd metacarpal and attaches to proximal phalynx of thumb
Abductors and Flexors insert into proximal Phalynx
Opponens inserts into metacarpals
Lumbricals
Arise from Flexor Digitorum Profundus Tendons over metacarpals
Wind around radial side of heach finger inserting into dorsal extensor expansion
extend interphalangeal joints at teh same time as flexing intermetacarpal joints
wave bye-bye
Intrinsic Muscles of the Hand (Deep & Dorsal)
Palmar Interosseous muscles (3)
Originate on metacarpal medial to middle finger
Wind around finger and insert into extensor expansion
wave bye-bye
Dorsal Interosseous muscles (4)
webbing between metacarpals
wind around side lateral to middle finger and attach to extensor expansion
PAD - Palmar interosseous adduct
DAB - Dorsal interosseous abduct
Brachial Plexus
Ganglion (C7-T1)
Trunks (superior, middle, inferior) - supraclaviclular
Divisions (anterior, posterior) - behind clavicle
Cords (lateral, middle, posterior - named according to relationship to axiliary artery)
Nerves
Musculocutaneous Nerve
C5,6,7 anterior division
pierces coracobrachialis
descends in anterior compartment of arm (biceps superficial, brachialis deep)
at elbow - lateral to tendon of biceps - becomes superficial - lateral cutaneous nerve of forarm
Motor Functions:
Brachialis, Biceps brachii, Corocobrachialis .
Sensory Functions: lateral half of the anterior forearm, and a small lateral portion of the posterior forearm.
Ulnar Nerve
(C7),8.T1 anterior division
down medial side of artery
passes behind medial epicondyle (pins & needles)
slips between two heads of FCU (humoral and ulnar)
tucks in under FCU (FDP deep)
passes superficial to flexor retinaculum (next to pisiform)
Motor Functions: Innervates the muscles of the hand (apart from the thenar muscles and two lateral lumbricals), flexor carpi ulnaris and medial half of flexor digitorum profundus.
Sensory Functions: Innervates the anterior and posterior surfaces of the medial one and half fingers, and associated palm area.
Median Nerve
C5, 6, 7, 8, T1, medial & lateral root
anterior/lateral to artery
crosses diagonally in front and ends medial at elbow
comes through centre of cubital fossa
slips between fibrous arch of FDS
FDS superficial, FDP deep
beneath flexor retinaculum (carpal tunnel)
Motor Functions: Innervates most of the flexor muscles in the forearm (except FCU and half FDP), the thenar muscles, and the two lateral lumbrical muscles that move the index and middle fingers.
Sensory Functions: Gives off the palmar cutaneous branch, which innervates the lateral part of the palm, and the digital cutaneous branch, which innervates the lateral three and a half fingers on the anterior (palmar) surface of the hand.
Axiliary Nerve
C5, 6.
Emerges above teres major
Motor Functions: Innervates the deltoid, teres minor and the long head of the triceps brachii.
Sensory Functions: Gives off the superior lateral cutaneous nerve of arm, which innervates the inferior region of the deltoid (“regimental badge area”).
Radial Nerve
C5, 6, 7, 8, T1
Emerges below teres major
runs diagonally across posterior aspect of shaft of humerus (prone to injury)
tucks in under cover of brachioradialis
splits into (superficial) radial nerve and (deep) posterior interosseous
superficial - continues under brachioradialis, onto back of hand, over anatomical snuff box onto dorsum of hand
deep - passes through supinator to deep layer of posterior compartment and supplies all 12 muscles
Motor Functions: innervates the triceps brachii, and the extensor muscles in the posterior compartment of the forearm.
Sensory Functions: Innervates the posterior aspect of the arm and forearm, and the posterior, lateral aspect of the hand.
Arteries of Upper Arm Segments
SUBCLAVIAN (outer border of first rib) AXILARY (lower border of teres major) BRACHIAL (elbow joint) RADIAL & ULNAR
Main arteries are on flexor segments so they aren’t stretched
Veins of Arm
DEEP VEINS
usually paired vena comitantes
connected at intervals by short transverse branches
relatively small, most drainage is superficial
SUPERFICIAL VEINS
commence at dorsal venous arch (fist forces blood in)
BASILIC and CEPHALIC veins come from medial and lateral sides of dorsal venous arch
Basilic Vein
From medial side of DORSAL VENOUS ARCH
winds around ulnar border to anterior surface
pierces fascia on medial side of biceps
joins with brachial veins to form AXILIARY VEIN
Cephalic Vein
From lateral side of DORSAL VENOUS ARCH
winds around radial border of forearm to anterior surface
gives off MEDIAL CUBITAL VEIN
runs up lateral side of biceps into deltopectoral groove to merge with AXILIARY VEIN
Axiliary Artery
3 segments based on relationship to pec minor
- above, distal, deep
supplies wall of axila, anterior chest, and anastamoses around humerus
Brachial Artery
Starts medial to humerus, at elbow becomes anterior
Tendon of biceps lateral
Brachial artery in middle
Median nerve medial
Gives off PROFUNDUS BRACHII (deep brachail artery)
winds around back of humerus diagonally into posterior compartment, runs together with radial nerve
Radial Artery
Tucks under cover of brachioradialis with superficial branch of radial nerve
Wind onto back of dorsum of hand
radial artery passes beneath tendons of anatomical snuffbox (abd policus longus, ext policus brevis)
radial nerve forms part of the roof
superficial palmar branch crosses superficial to flexor retinaculum and onto superficial part of hand
Gives off DEEP PALMAR ARCH (more proximal than superficial palmar arch)
Ulnar Artery
Disappears under cover of FCU with ulnar nerve
Crosses superficial to flexor retinaculum (exposed to wrist lacerations)
Gives rise to SUPERFICIAL PALMAR ARCH
Gives off COMMON INTEROSSEOUS ARTERY (split into posterior and anterior)
White matter vs Grey matter
White matter = myelinated
Grey matter = cell bodies
Spinal Nerve Ending
L1/L2
Thalamus
Part of diencephelon
Major sensory relay to cortex
Many subnuclei
Hypothalamus
Part of diencephalon
Regulates homeostasis (temp, blood volume / pressure, ion concentration, pH, O2, glucose) Controls pituitary
Peripheral Nerve Layers
Axon
Schwann Cells
Endoneurium - loose supporting tissue within fascicle
Perineurium - surrounds fascicle
Epineurium - surrounds collection of fascicles
Meissner Corpuscles
Epidermis Rapidly Adapting High Density 40% of total Type II (Aβ) Fiber Dynamic Deformation, skin motion, detecting slipping objects
Merkel Complexes
Epidermis/Dermis Slowly Adapting Smallest Receptor Field 25% of total Type II (Aβ) Fiber Fine tactile, form and texture
Ruffini Organs
Dermis Slowly Adapting Sensitive to stretch and direction, position Proprioceptive 20% of total Type II (Aβ) Fiber
Pacinian Corpuscles
Dermis/Subcutaneous Rapidly Adapting Low density Most sensitive Vibration (e.g. when grasping) 15% of total Type II (Aβ) Fiber
Proprioception
- Receptor Type
- Afferent Axon Type
- Axon Size
- Conduction Velocity
Muscle Spindle (around individual muscle fibres)
Type Ia (Aα) Fiber Ia, Type II (Aβ) Fiber
12-30µm (largest)
80-120 m/s
Touch
- Receptor Type
- Afferent Axon Type
- Axon Size
- Conduction Velocity
Merkel, Meissner, Pacinian, Ruffini
Type II (Aβ) Fiber
6-12µm
35-75 m/s
Pain / Temperature
- Receptor Type
- Afferent Axon Type
- Axon Size
- Conduction Velocity
Free nerve endings
Type III (Aδ) Fiber
1-5µm
5-30 m/s
Pain / Temperature / Itch
- Receptor Type
- Afferent Axon Type
- Axon Size
- Conduction Velocity
Free nerve endings (unmyelenated)
Type IV (C) Fiber
- 2-1.5µm
- 5-2 m/s
End of Spinal Cord
L1/2
Lumbar puncture at L3/4 into Cauda Equina
Foramen of Skull and their structures
Cribriform Plate - CNI
Optic Canal - CNII, Opthalamic Artery
Superior Orbital Fissure - CNIII, CNIV, CNV1, CNVI
Foramen Rotundum - CNV2 (maxillary)
Foramen ovale - CNV3 (mandibular)
Foramen Spinosum - Middle Meningeal Artery
Foramen Lacerum - Filled with cartilage - internal carotid exits here towards cavernous sinous and exits under optic canal
Internal Auditory Meatus - CNVII, CNVIII
Jugular Foramen - CNIX, X, XI, sigmoid sinus / internal jugular
Hypoglossal Canal - CNXII
Veins of Skull
Emissary - drain blood from scalp (can infect sinuses)
Diploic - drain spongy bone
Supperior Saggital Sinus
Superior Cerebral Veins (drain into saggital sinus)
Inferior Saggital Sinus
Great Cerebral Vein
Straight Sinus
Confluence of Sinuses
Transverse Sinus
Sigmoid Sinus (at petrous part of temporal bone)
Inferior Petrosal Sinus
Superior Petrosal Sinus
Cavernous Sinus (either side of body of sphenoid)
Middle Meningeal Artery origins
Enters through Foramen Spinosum and branches to Anterior / Posterior divisions
Lies in extradural space (fracture of Pterion can rupture artery)
Largest, most important branch of maxillary artery
Maxillary artery branches from External Carotid (also gives off Superficial Temporal and Occipital arteries)
Layers of SCALP
Skin
Connective Tissue (dense - contains neurovascular structures)
Aponeurotic Layer (of occipotofronralis)
Loose Connective Tissue (allows scalp to move)
Pericranium / Periosteum
Fibrous septa in connective tissue hold vessels open and decrease ability to clot
Rich anastamosis of branches of external/internal carotids
Small lacerations will bleed profusely
Occipitofrontalis
Wrinkles Forehead (frontalis) / Raises Eyebrows (w/ occipitalis)
From external occipital protruberance to supraorbital margins (eyebrows)
Extends laterally to zygomatic arches
Lacerations of aponeurosis will gape (frontalis & occipitalis will pull in either direction)
Muscles of Facial Expression (4 layers)
Same as SCALP but missing loose connective tissue (L)
Instead of aponeurosis has muscles of facial expression
- obicularis (around orrifices)
- levators/depressors
Attach to skin of face and bone/fascia underlying - produce expression
Supplied by CNVII
Dermatomes of Head & Neck
VI (opthalmic) - nose, eyes, posterior to level of ears
V2 (maxillary) upper lip, cheek, temporal
V3 (mandibular) - chin, jaw, anterior to ears
X (auricular branch) - external meatus
Cervical Plexus - Neck & behind ear
C2/C3 posterior head and neck
Arterial Supply of Face and skull
(branches from external carotid artery) Lingual Artery (deep to hyoglossus) Facial Artery (winds over inferior angle of mandible, tortuous course towards medial angle of eye) Superficial Temporal Artery Posteterior Auricular Artery Occipital Artery Ascending pharyngeal
(branches of opthalmic artery / internal carotid)
Supratrochlear branches
Supraorbital branches
Parotid Gland
Serous Salivery Gland
Sits below Zygomatic Arch, in front of mastoid process pf temporal bone, above angle of mandible, behind massiter, superficial to styloid process
Wrapped in dense fibrous fascia (mumps is inflammation of glands - causes pain when fascia stretches)
Produces Saliva, duct emerges from anterior aspect of gland, onto massiter, turns inwards, pierces buccinator and enters oral cavity near second upper molar.
CNI
Olfactory Nerve
Sensory (smell)
Exit: Cribriform Plate
Special Somatic - Smell
CNII
Optic Nerve
Sensory (sight)
Exit: Optic canal
Some axons cross optic chiasm
Travel to Lateral Genticulate Nucleus within Thalamus
Thalamus to visual cortex (optic radiation)
- temporal: superior visual field
- parietal: inferior visual field
Special Somatic - Vision
CNIII
Occulomotor
Motor
Exit: Superior Orbital Fissure
Nuclei:
- Midbrain General Somatic Motor (Superior Rectus, Inferior Rectus, Medial Rectus, Inferior Oblique, levator palpebrae superioris)
- Midbrain General Visceral Motor (parasympathetic from Edinger Westphal nucleus - iris/sphincter pupillae[pupils], ciliary muscle[accomodation])
Dysfunction:
Down and out, ptosis, dilation (mydriosis)
third nerve paulsy due to uncal herniation
CNIV
Trochlear
Motor
Exit: Superior Orbital Fissure
Exits dorsal surface of brainstem & crosses to contralateral side
Nuclei:
- Midbrain General Somatic Motor (Superior Oblique)
Dysfunction:
Diplopia (double vision) - can’t look down and in
CNV
Trigeminal Nerve
Mixed (motor and sensory)
Nuclei:
- Midbrain General Somatic Sensory [mesencephalic-proprioception]
- Pons General Somatic Sensory [chief sensory - temp/touch]
- Pons/Medulla/Spinal Cord General Somatic Sensory [spinal trigeminal nucleus - pain]
- Pons Branchial Motor (motor nucleus - mastication, mylohyoid, tensor tympani, tensor veli palatini)
(trigeminal ganglion sits at petrous part of temporal bone)
V1 - OPTHALAMIC (superior orbital fissure)
- supraorbital
- supratrochlear
V2 - MAXILLARY (foramen rotundum)
V3 - MANDIBULAR (foramen ovale)
Sensory input from face, teeth, eyes, nose, external ear, anterior 2/3 tongue (lingual) & dura Mastication & mylohyoid Lateral & Medial pterygoids Temporalis Tensor Tympani (inner ear) Tensor Veli Palatini (raise soft palate)
CNVI
Abducent Nerve
Motor
Exit: Superior Orbital Fissure
Nuclei:
- Pons General Somatic Motor (Lateral Rectus)
Dysfunction:
Diplopia (double vision) - can’t abduct
CNVII
Facial Nerve
Mixed (motor and sensory)
Wraps around behind CNVI nucleus
Exit: Internal Acoustic Meatus
Nuclei:
- Pons Branchial Motor (facial expression, stapedius, digastric)
- Pons General Visceral Motor (parasympathetic/greater petrosal - lacrimal, sublingual, submandibular salivary glands)
- Pons/Medulla/Spinal Cord General Somatic Sensory (small region near external auditory meatus)
- Medulla General and Special Visceral Sensory (nucleus solitarius - chorda tympani - taste anterior 2/3)
Exits skull via stylomastoid foramen (through internal auditory meatus), between mastoid and styloid process inferior
gives off posterior auricular nerve and supplies occipitalis (and digastric)
enters posteromedial surface of parotid
creates plexiform arrangement (pes anserinus)
gives off 5 terminal branches
- Temporal (frontalis)
- Zygomatic (orbicularis occuli)
- Buccal (buccinator)
- Mandibular (orbicularis oris)
- Cervical (platysma - clench teeth)
CNVIII
Vestibulocochlear
Sensory
Exit: Internal Auditory Meatus
Nuclei:
- Pons/Medulla Special Somatic (hearing/equilibrium)
- Pons Special Somatic (hearing/equilibrium)
Dysfunction:
Nystagmus, vertigo, hearing loss, tinitus
CNIX
Glossopharyngeal
Mixed (motor and sensory)
Exit: Jugular Foramen
Nuclei:
- Medulla: Branchial Motor (nucleus ambiguus - stylopharyngeus)
- General Visceral Motor (parasympathetic to parotid - from inferior salivatory nucleus)
- Pons/Medulla/Spinal General Somatic (pharynx, middle ear, posterior 1/3 touch)
- Medulla General and Special Visceral (nucleus solitarius - taste post 1/3, carotid body)
CNX
Vagus
Mixed (motor and sensory)
Exit: Jugular Foramen
Inside carotid sheath, alongside trachea, posterior to hilum of lung, anterior to oesophegus
Nuclei:
- Medulla Branchial Motor (nucleus ambiguus - levator palati, pharynx, larynx, upper oesophegus, soft palate, palatoglossus(tongue))
- Medulla General Visceral Motor (dorsal motor nucleus - parasympathetic - organs from pharynx to abdomen)
- Pons/Medulla/Spinal General Somatic Sensory (pharynx, larynx, oesophagus, behind ear & auditory meatus)
- Medulla General and Special Visceral (nucleus solitarius - baroreceptors and chemoreceptors of aortic arch, afferents from visceral organs)
Dysfunction:
Hoarse voice, dysphasia
CNXI
Spinal Accessory (upper 5-6 of cervical spinal cord)
Motor
Exit: Jugular Foramen (enters via Foramen Magnum)
Heads beneath or through sternocleidomastoid to floor of posterior triangle, crosses obliquely on levator scapulae and dissapears under trapezius)
Nuclei:
- Spinal Branchial Motor (sternocleidomastoid, upper trapezius)
Dysfunction:
Won’t be able to shrug ipsilateral shoulder,
can’t turn head to contralateral side
CNXII
Hypoglossal
Motor
Exit: Hypoglossal Foramen
Nuclei:
Medulla General Somatic Motor (tongue intrinsic and extrinsic - hyoglossus, genioglossus, styloglossus) (all except palatoglossus)
Dysfunciton:
Tongue deviates towards side of lesion
Cranial Nerve Nuclei in Motor Columns (medial to lateral)
- General Somatic
- Branchial (gill/face)
- Visceral
General Somatic CNIII (eye) CNIV (eye) CNVI (eye) XI (neck muscles) XII (tongue)
Branchial
V (mastication)
VII (facial expression)
X & IX (nucleus ambiguus - levator palati, stylopharyngeus)
Visceral III (edinger-westfall nucleus - pupil/iris) VII (superior salivatory nucleus) IX (inferior salivatory nucleus) X (dorsal motor nucleus of vagus)
Cranial Nerve Nuclei in Sensory Columns (medial to lateral)
- General/Special Visceral
- General Somatic (pain/fine touch)
- Special Somatic
General/Special Visceral
VII, IX, X (nucleus solitarius) - taste & autonomic
I (smell)
General Somatic
V (sensation of face and cranial dura)
V,VII,IX,X (skin behind ear & auditory meatus)
Special Somatic
VIII (hearing and equilibrium)
II (vision)
Reticular Formation
In tegmentum. Thalamus -> grey of spinal cord
Rostral (midbrain & upper pons): maintain alert conscious state, modulate forebrain activity (reticular activating system)
Caudal (pons & medulla): carry out important motor reflex and autonomic functions through cranial nerve nuclei and spinal cord (e.g. breathing, HR, etc.)
Nucleus Ambiguus
Mostly Motor
Lies behind inferior olive
CNIX: stylopharyngeus
CNX: levator palati, pharynx, larynx, upper oesophegus, palatoglossus(tongue)
(soft palate muscles for speech and swallowing)
Nucleus Solitarius
Extends from Pons to nucleus gracilis (mostly medulla)
Rostral (gustatory nucleus);
afferents from taste and palate (VII, IX, X)
Caudal (visceral sensory)
afferents from heart, abdominal viscera, aortic body (X)
baroreceptors & chemoreceptors from carotid body and sinus (IX)
mediate the gag reflex, the carotid sinus reflex, the aortic reflex, the cough reflex, the baroreceptor and chemoreceptor reflexes, several respiratory reflexes and reflexes within the gastrointestinal system regulating motility and secretion.
Brain XRAY, MRI, CT, Ultrasound
XRAY
- shows skull and bony lesions
MRI
- best for soft tissue (not bones)
- non ionising radiation
- fMRI track blood oxygen level
- expensive
- contraindicated for pt’s with metal implants
- better contrast resolution
CT
- positron emition tomography(identify metabolic function with glucose labelling)
- fast
- good for bones
- better spatial resolution
- Grey & White matter almost appear the same
- Ionising RADIATION!
Ultrasound
- used in neonates
- fontanel act as acoustic window
- good for viewing glands (thyroid, submandibular, carotids)
Amygdala
Implicit emotional learning
Related to depression and anxiety
Kluver-Bucy Syndrome: tameness/loss of fear
Sympathetic NS Origins
T1-L2
Preganglionic neurons in intermediolateral cell column
Sympathetic Chain
Prevertebral Ganglia
Generally more distant from organs
Parasympathetic NS Origins
Cranial
S2-S4
Generally closer to or within organs
Fovea
Area of high visual acuity
Avascular (gets nutrients form choroid)
High density of cones (colour)
No rods (nightvision)
Lamina Cribosa
continuation of 1/3 of scleral fibres (dense connective tissue) in the eye creating web/holes for axons of optic nerve
In glaucoma lamina cribosa can be pushed out and damage axons travelling through it
Blood supply to the eye
Central renal artery (tributary of opthalamic artery, branch of internal carotid) - supplies internal retina
Long Posterior Ciliary artery - travel in chroroid all the way to the front of the eyeball & feeds photoreceptors
Short Posterior Ciliary Artery - doesn’t travel far in choroid, supplies photoreceptors
Anterior Ciliary Artery - supplies anterior structures like conjunctiva
Edinger-Westphall nucleus
Parasympathetic cranial nerve nucleus of the oculomotor nerve (cranial nerve III), supplying the constricting muscles of the Iris and the ciliary muscle.
Photoreceptors
Light activates Rhodopsin -> transducin -> Phosphodiesterase -> cGMP breaks down to GMP -> Na+ influx ceases -> Cell becomes hyperpolarized -> releases less neurotransmitter (glutamate)
Bipolar Cells (Vision)
ON or OFF types
Important in ‘through’/’central’ pathway
Important for spatial vision & colour vision
ON -> depolarize in response to light
OFF -> hyperpolarize in response to light
Ganglion Cells (Vision)
Types: ON, OFF, M, P
Release Glutamate
Fire action potentials (increase/decrease in response to light)
Have a ‘receptive field’
synapse in LGN of thalamus
P&M cell pathways terminate in seperate layers of Primary Visual Cortex (V1)
M: Magnocellular (10%) - big cells - motion P: Parvocellular (80%) - small cells - colour vision & acuity
Amacrine Cells (Vision)
Lateral inhibition
Axonless
Allow us to see movement
Horizontal Cells (Vision)
Lateral inhibition between photoreceptors
Use GABA (inhibitory)
respond to light by hyperpolarizing
Involved in ‘surround’ response pathway of receptive field.
Lateral Genticulate Nucleus (LGN)
Thalamic relay station for visual pathway
Magnocellular Layers 1&2
Parvocellular Layers 3,4,5,6
Ipsilateral Eye Layers: 2,3,5
Contralateral Eye Layers 1,4,6
Give off Optic Radiations to Primary Visual Cortex V1 (around calcarine fissure, central vision most posterior)
Intrinsically Photosensitive Ganglion Cell
Contain melanopsin Responsible for - Circadian rhythm / sleep (SCN) - Pupil response (CNII -> OPN -> Erdinger-Westphal-> CNIII -> Ciliary Ganglion -> sphincter pupillae) - Information about light levels - photophobia
Suprachiasmatic Nucleus (SCN)
ipGCs project to SCN in Hypothalamus
Drives circadian rhythm
Semicircular Canals
Sensory information about Head Position Hair follicles (cupula) in Ampulla Discharge in relation to changes in position (directional) due to flow of endolymph
Otolith Organs (saccule & utricle)
Sensory information about linear acceleration
Dorsal Visual Stream
Area MT (Middle Temporal Lobe) specialized for processing object motion Directional selective Respond to different types of motion
Ventral Visual Stream
Area V4
Orientation and colour selective
Important for perception of shape and colour
Area IT (Inferior Temporal)
Major output area of V4
Important for visual memory and perception (esp faces)
Ossicles
Bones of middle ear
Malleus
Incus
Stapes
Match impedance of air to impedance of fluid within inner ear
Size: 20:1 (tympanic membrane»_space; oval window)
Lever action 1.3:1
Lower Motor Fiber
- Efferent Axon Type
- Axon Size
- Conduction Velocity
Type α (Aα) Fiber,
13-20µm
80-120m/s
Sensory Fiber & associated receptor Type Ia (Aα) Type Ib (Aα) Type II (Aβ) Type III (Aδ) Type IV (C)
Ia - muscle spindle
Ib - golgi tendon organ
II - muscle spindle & cutaneous mechanoreceptors
III - touch and pressure noiceceptors, temp (cold)
IV - noiceceptors, temp (warmth)
Basal Ganglia
In telencephalon
Help Motor Cortex formulate and execute movement
Allow selection of patterns (‘subroutines’)
Evaluate success of actions in achieving goals
Initiate movement
Damage leads to Parkinsons & Huntingtons
Striatum (caudate and putamen)
Globus Pallidus (GPi & GPe)
Subthalamic Nucleus
Substantia Nigra
Direct (select subroutines)
MC (+)-> Striatum (-)-> GPi (-)-> Thalamus (+)-> SMC
Indirect (suppress movement)
MC (+)-> Striatum (-)-> GPe (-)-> Subthalmic (+)-> GPi (-)-> Thalamus (+)-> SMC
Initiation
MC (+)-> Striatum (-)-> Sub Nigra (+)(-)-> Striatum (direct or indirect)
Middle Cerebral Artery
Origin: ICA (bifurcation with ACA)
Gives of lenticulostriate arteries (supply basal ganglia and internal capsule)
Supplies: Lateral surface
Territories: motor & sensory (except lower limb), parieto-occipital association, language (on dominant side)
Anterior Cerebral Artery
Origin: ICA (bifurcation w/ MCA)
has anterior communicating artery (gives off small branches to supply optic chiasm & anterior hypothalamus)
Supplies: Medial frontal and parietal lobes
Territores: Motor & sensory (lower limbs)
Posterior Cerebral Artery
Origin: Basilar (from joining of vertebral)
give off small brances to ventral midbrain, thalamus, posterior hypothalamus
Supplies: Medial and inferior temporal and occipital lobes
Territores: visual cortex
Misc CNS arteries
- Opthalmic
- Anterior Choroidal
- Superior Cerebellar Artery
- Pontine perforating arteries
- Anterior Inferior Cerebellar Artery
- Posterior Inferior Cerebellar Artery
- Anterior Spinal Artery
- Posterior Spinal Artery
Opthalmic: from ICA to optic cavity, top of nasal cavity, and frontal scalp
Anterior Choroidal: from ICA to structures in deep lateral hemispheres, optic tract, lateral ventricles, hippocampus
SCA: from basilar artery
Pontine: from basilar to Pons
AICA: from basilar a.
PICA: from basilar or vertebral a.
Anterior Spinal: from both vertebral a. (& segmental branches of aorta)
Posterior spinal: one from each vertebral a. (& segmental branches of aorta)
*spinal arteries anastamose through circumferential branches
Cochlea Structure
Scala Vestibuli Scala Media (endolymph - high K+) - stria vascularis (recycle K+) - tectorial membrane - inner hair cells (project ot brainstem nuclei) - outer hair cells (amplify movements of basilar membrane)* - basilar membrane (wider at apex) Scala Tympaniy (perilymph - low K+)
*antibiotics cause loss of OHC & loss of hearing (100 fold less sensitive)
Blood Supply of Nasal Cavity
SUPERIOR
- ethmoidal arteries (branches of opthalmic arteries)
INFERIOR
- greater palatine artery (branch of maxillary artery - ECA)
POSTERIOR
- sphenopalatine artery (branch of ECA) - nosebleed (epistaxis)
ANTERIOR
- superior labial arteries (branch of facial artery)
- lateral branch of facial arteries (from ECA)
- anastomoses from superior/inferior/posterior
Nerve supply of Nasal Cavity
SUPERIOR/ANTERIOR - CNI - olfactory - CNV1 - Anterior ethmoidal nerves INFERIOR/POSTERIOR - CNV2 - Greater/Lesser palatine
Pharynx Range
Base of skull -> C6
Cerebellum
Coordinate Timing and Sequence
Maintain Muscle Tone
Motor Learning
Planning Sequences of muscle activation for complex movement
ATAXIA: inability to integrate / cordinate movement
Effects of unilateral lesion are ipsilateral
Anterior Lobe Syndrome:
- ataxic gait (drunken sailor) - can’t walk in a line
- loss of inter-limb coordination (heel-shin test)
Posterior Lobe Syndrome:
- Dysmetria (nose-finger overextension)
- Dysdiadochokinesia (rapid alternate movements - palm test)
- Speech abnormality (slurring, explosive speech)
Flocculonodular Lobe Syndrome:
- Truncal Ataxia (can’t stabilize trunk)
Hippocampus
In Medial Temporal Lobe
Critical for learning and memory
Most sensitive structure for induction of seizures (epilepsy)
Venous Drainage of Skull
Superior Venous Sinus Inferior Venous Sinus Great Cerebral Artery Straight Sinus Confluence Transverse Sinus Sigmoid Sinus Petrosal Sinus (inferior superior) Cavernous Sinus Superior Orbital Vein
Muscles of tongue (intrinsic, extrinsic) & mouth
Floor of Mouth:
Digastric -
Mylohyoid - (large) mandible to hyoid
Geniohyoid - (small) mandible to hyoid
Extrinsic Tongue:
Genioglossus - tongue to mandible (protrude tongue) -XII
Palatoglossus - tongue to palate (elevate tongue) - X
Styloglossus - tongue to styloid process (retract tongue) - XII
Hypoglossus - tongue to hyoid (depress tongue) -XII
Intrinsic Tongue:
Transverse, vertical, superior/inferior longitudinal - XII
Tongue innervation
- motor
- sensory (touch)
- sensory (taste)
Motor:
XII (except palatoglossus - X)
Sensory (touch):
Ant 2/3 - V3
Pos 1/3 IX
Sensory (taste):
Ant 2/3 - VII
Pos 1/3 - IX
Teeth #
Incisors (4)
Canine (2)
Premolars (4)
Molars (6) - including wisdom
x2 for upper and lower
supplied by superior/inferior alveolar nerve - V2/V3
supplied by maxillary artery -> alveolar arteries
Larynx length
Epiglottis -> C6/lower border of cricoid
Structures of larynx
Hyoid bone Epiglottic cartilage Thyroid cartilage (open posteriorly) Cricoid cartilage (lamina & arch) Arytenoid cartilages (vocal & muscular processes) vestibular fold (false vocal chords) vocal ligaments (adduct = phonation)
Muscles
Posterior cricoarytenoid (abduct vocal ligaments)
Lateral cricoarytenoid (adduct vocal ligaments)
cricothyroid (lengthen vocal fold)
vocalis / thyroarytenoid (relax vocal fold)
transverse/oblique arytenoids (close rima glottis)
Nerves
superior laryngeal
- external laryngeal (cricothyroid muscle)
- internal laryngeal (sensory above vocal ligaments)
inferior laryngeal (sensory below vocal ligaments)
recurrent laryngeal (all other muscles - hoarse voice)
Blood supply
superior laryngeal vessels (lateral to larynx)
inferior thyroid vein (medial to larynx)
Tracheotomy location
cricothyoid membrane
Anterior Triangle of Neck
- Borders
- Structures
Mandible, Sternocleidomastoid, Manubrium
Posterior Triangle of Neck
- Borders
- Structures
Behind sternocleidomastoid, in front of trapezius, above medial 1/3 of clavicle
Transmitting structures to upper limb and back (e.g. brachial plexus)
Organisation and Fasica of Neck
- Superficial Fascia
- Investing Fascia
- Pretracheal/Buccopharyngeal Layer
- Prevertebral Layer
- Carotid Sheath
SUPERFICIAL
- platysma (blends with muscles of face - CNVII)
- EJV (angle of mandible -> descent on SCM)
- AJV
INVESTING
- trapezius
- sternocleidomastoid (SCM)
[between] - strap muscles
Suprahyoid msucles (hyoid to skull - elevate larynx)
Infrahyoid muscles (hyoid to sternum/clavicle/etc - depress larynx)
innervated by anterior rami of cervical nerves
PRETRACHEAL(to hyoid)/BUCCPHARYNGEAL
- Thyroid / Parathyroid
- Thymus
- Trachea
- Oesophegus
PREVERTEBRAL
- vertebra
- scalenus anterior (attach to anterior tubercles & first rib)
(subclavian & brachial plexus passes between)
- scalenus medius (attach to posterior tubercles & first rib)
- longus colli (maintains curvature of lordosis)
CAROTID (expansile)
- Carotid
- Jugular
- Vagus
Cervical Vertebra Features
NERVE ROOTS PASS IN FRONT FACET JOINTS!
Transverse mass - anterior & posterior tubercles w/ transverse foramen
bifid spinous process (increased surface area for muscle attachment) - C7 has longest
articular surfaces at 45degrees w/ uncinate processes on C3-6 (keep movement in saggital plane) - innervated by posterior rami
Largest intervertebral discs throughout vertebral column (prolapse usually trauma related)
Atypical Cervical Vertebra Features
- Atlas
- Axis
NERVE ROOTS PASS BEHIND FACET JOINTS!
Atlas (C1)
- No body
- anteiror/posterior arches
- facet for dens
- saucer-shaped upper surfaces for occipital condyles
- longest transverse process
- loose fibrous capsule permits nodding (F/E) - 20% of ROM
Axis (C2)
- Dens (odontoid process) - body from C1 (atlas)
- 2 lateral facet joiunts
- allow 50% of spinal rotation
- Strong spinous process (muscles of stabilisation)
- rectus capitis posterior major/miinor
- superior/inferior oblique
- Ligaments stabilize dens (endagement of cord)
- transverse ligament / cruciform
- alar ligaments (resist range of rotation of head around dens)
Internal Carotid Course & Branches
Branch of common carotid (C4)
runs in carotid sheath
through carotid canal, above foramen lacerum, through cavernous sinus
gives off opthalmic, MCA, ACA, anterior choroidal, posterior communicating
Contains carotid sinus and body
External Carotid Course & Branches
Branch of common carotid (C4) Anterior Branches - Superior thyroid artery - Lingual artery - Facial artery
Posterior Branches
- Occipital
- Posterior Auricular (behind ear)
Deep
- Ascending pharyngeal artery
Terminal
- Maxillary artery (middle meningeal, sphenopalatine, alveolar)
- Transverse facial (eye level)
- Superficial temporal artery
**Some Anatomists Like Freaking Out Poor Medical Students
S - superior thyroid artery A - ascending pharyngeal artery L - lingual artery F - facial artery O - occipital artery P - posterior auricular artery M - maxillary artery S - superficial temporal artery
Level of bifurcation of carotid artery
C4
C3/4 is also upper border of thyroid cartilage
Ligaments of Cervical Spine
Resist movement in saggital plane (F/E) - susceptible to whiplash injury
Ligamentum Nuchae (from supraspinatus)
ATLAS to occiput
Posterior atlanto-occipital membrane (from ligamentum flavum)
AXIS to occiput Anterior atlanto-occipital membrane (from anterior longitudinal ligament) Membrana tectoria (from posterior longitudinal ligament)
Thyroid
Between Tyroid cartilage & 6th Tracheal ring
Isthmus between 2nd & 3rd Tracheal rings
encased in pretracheal fascia
50% of cases have pyramidal lobe
Descends from Foramen Caecum during development
Superior Thyroid Artery (from external carotid)
Inferior thyroid artery (from subclavian)
(10%) Thyroid ima artery (subclavian)
Superior Thyroid Veins (IJV)
Middle Thyroid Veins (IJV)
Inferior Thyroid Veins (subclavian)
Internal/External branch of superior laryngeal (CNX) recurrent laryngeal (CNX)
Cervical Plexus
from ventral rami of C1-C4
Phrenix (C3,4,5) - descends on scalenus anterior in posterior triangle into thorax
Superficial (cutaneous) (C2,3,4)
- lesser occipital
- greater auricular
- transverse cervical
- suprascapula
Deep branches
- ansa cervicalis (motor - strap muscles of neck)
Imaging modalities of Orbit
CT
MRI
Ultrasound (of globe)
Dacrystogram (imaging of lacrimal duct with dye)
Best Imaging modality for paransal sinuses
CT - excellent delineation of bony anatomy
MRI good for suspected soft tissue tumors
Best imaging modality for mandible and maxilla
OPG (Orthopantomogram) - dentist XRAY
Best Imaging modalities for thyroid
CT, Ultrasound, PET
Best Imaging modalities for vessels
Ultrasound
CT/CT angiography
MRI/MRI angiography
Digital subtraction angiography
Best Imaging modality for temporal bones
thin slice CT
due to complicated bony anatomy of the region
Can image: inner ear bony labrynth ossicles mastoid air cells facial nerve course
Adrenal Layers (from outer to inner) and their products
Capsule
- N/A
Zona Glomerulosa
- Aldosterone
Zona Fasciculata
- Cortisol
Zona Reticularis
- Dehydroepiandrosterone (DHEA), Androgens, Oestrogens
Medulla
- Catecholamines (Adrenaline, NA, Dopamine)
Hip joint & Acetabulum
- Ilium (superior)
- ischium (postero-inferior)
- pubis (antero-inferior)
meet to form lunate surface of acetabulum w/ notch - labrum (fibrocartilage deepens cup & increases surface area)
Blood supply via anastamoses from Medial & Lateral Femoral Circumflex Arteries from femoral artery
ligaments:
iliofemoral (front, strong - upside down V shape)
pubofemoral & ischiofemoral (behind, weak)
Cuff of ‘fixator muscles’ to stabalise head of femur (‘rotator cuff’).
- external/outward rotators
- run parallel to neck of femur
- pull head of femur into socket
Gluteal muscles cover joint posteriorly
Gluteus medius & minimus abduct hip & maintain position in coronal plane (injury = trendellenberg gait)
Adductor muscles from pubis/symphisis to medial femur
Innervation:
- Femoral (crosses in front of joint)
- Obturator (L2,3,4 - crosses medial aspect of joint)
- Sciatic (passes posterior and medial)
Referred pain:
FROM hip via obturator to knee/thigh
TO hip from lumbar spine
Hip dislocation usually posteriorly, endanger blood supply and sciatic nerve
Femur
Head - directed upwards, medially, forwards - with fovea - non articular, has ligament attached regresses after puberty) - protected by psoas bursa anteriorly Anatomical Neck - line of growth plate Greater Trochanter - gluteal muscles Lesser Trochanter Intertrochanteric Line (anterior) Intertrochanteric Crest (posterior)
Superior Trabecular System:
- Arcuate - resist bending forces
- Vertical - resist compression
Inferior Trabecular system
- Medial & Lateral - resist pull on greater & lesser trochanter
Retinacular fibres provide blood supply to head of femur
Hip close packed position
Hip extended
Abducted
Medially Rotated
Position of greatest stability
Ligaments taught
Knee Joint
2 joints in one
- femur with tibia (tibiofemoral)
- femur with patella (patellofemoral)
Large ROM – most stable in extension (close packed)
Anterior & posterior cruciate ligaments (intracapsular but extrasynovial)
- Anterior tibial to posterior lateral condyle of femur
- Posterior tibial to medial condyle of femur
- Primary stabilisers in A-P direction
- PCL prone to injury w/ impact to knee during flexion
Medial & lateral collateral ligaments
- M: resists valgus (abduction) and lateral tibial rotation, blends with capsule, attaches to meniscus, commonly injured
- L: resists varus (adduction), seperated from meniscus by popliteus tendon
Medial condyle 1cm larger than lateral
Femur rotates medially on tibia during extension (around tight ACL in last 15-20degrees)
Active contraction of popliteus (medial surface of tibia, lateral condyle) for flexion
Condyles surrounded by meniscus (fibrocartilagenous disc)
- increase area of contact by 33%
- medial meniscus is longer, less mobile, prone to injury
- ‘locked knee’ - torn meniscus & stuck
- no meniscus -> weight focused on centre -> osteoarthritis
Capsule reinforcements:
- Anterior - patella tendon & retinacular fibres
- Lateral - popliteus, biceps femoris, iliotibial tract
- Medial - ‘pes anserinus’ - Sartorius, Gracilis, Bursa, Semiteninosus
Posterior - oblique popliteal ligament
Pes Anserinus of Knee
Say Grace Before Tea
Sartorius - anterior compartment
Gracilis - medial compartment
Bursa
semiTendinosus - anterior compartment
Patellofemoral Joint
Maintained by 3 structures
- Strong vastus medialis muscle - pull patella medially
- Medial patellar retinaculum - keep patella medial
- Raised lip on lateral femoral condyle - prevent patella from moving laterally
Patella wants to move laterally because quadriceps aligned obliquely laterally
Problem with tracking = chondromalacia patellae
Gluteus Maximus
ORIGIN: Gluteal surface of ilium & sacrum
INSERTION: posterior iliotibial tract and gluteal tuberosity
INNERVATION: Inferior gluteal nerve
ACTION: Extend, lateral rotation, abduct thigh at hip
* Similar to posterior deltoid
Gluteus Medius & Minimus
ORIGIN: Superior posterior ilium
INSERTION: anterolateral aspect of greater trochanter
INNERVATION: Superior gluteal nerve
ACTION: medial rotation, abduction of hip
* similar to lateral fibres of deltoid
* prevent hip drop when walking
Piriformis, Obutrator, Gemelli, Quadratus Femoris
ORIGIN: Anterior surface of sacrum exiting via greater sciatic notch, inferior pubic ramus, inferior ischial ramus
INSERTION: (gluteal region) greater trochanter
INNERVATION: from sacral plexus
ACTION: lateral rotation
Piriformis:
Trianglular muscle forming part of wall of pelvis
Arises from middle 3 segments of sacrum anteriorly
exits via greater sciatic foramen
attaches on greater trochanter
Sacral plexus lies on piriformis
Obturator internus:
arises from internal surface of obturator membrane, margins of obturator foramen, and extends onto postero-superior bony surface and exits via the lesser sciatic foramen
Iliacus
ORIGIN: iliac fossa and passes beneath inguinal ligament
INSERTION: lesser trochanter
INNERVATION: femoral nerve
ACTION: Flex hip and maintains lumbar lordosis (w/ psoas)
Muscles of medial compartment of thigh
Adductors of hip (mostly)
- Pectineus
- Gracilis
- Adductor Brevis
- Adductor Longus
- Adductor Magnus
Muscles of anterior compartment of thigh
Flexion of hip and extension of knee
- Pectineus
- Sartorius
- Rectus Femoris
- Vastus Lateralis
- Vastus Intermedius
- Vastus Medialis
- Articularis Genus
Muscles of posterior compartment of thigh
Flexion of knee
- Biceps Femoris
- Semitendinosus
- Semimembranosus
Muscles of anterior compartment of leg
Dorsiflex foot and extend toes
Tibialis anterior
Extensor Hallucis Longus
Extensor Digitorum Longus w/ fibularis tertius
Muscles of posterior compartment of leg
Plantarflex foot and flex toes Gastrocnemius Soleus Tibialis Anterior Flexor Hallucis Longus Flexor Digitorum Longus
Muscles of lateral compartment of leg
Evert foot
Fibularis longus
Fibularis brevis
Tensor fascia lata
ORIGIN: below lateral iliac spine
INSERTION: Iliotibial tract
INNERVATION: superior gluteal nerve
ACTION: Flexes, abducts, medially rotates
* similar to anterior and lateral deltoid
Iliotibial tract
Lateral thickening of fascia lata of thigh
Extends from iliac crest to lateral proximal tibia
shared aponeurotic tendon of gluteus maximus (inserts posteriorly) and tensor fascia lata (inserts superior/anterior)
- prevent tilt/drop during swing phase
Pectineus
ORIGIN: Pubic crest
INSERTION: below lesser trochanter
INNERVATION: femoral and obturator nerves
ACTION: flexion of hip w/ iliopsoas, adduction of hip w/ adductors
Sartorius
ORIGIN: Anterior superior iliac spine
INSERTION: below medial condyle of tibia
INNERVATION: femoral nerve
ACTION: ‘dog poo muscle’ - sitting cross legged
Vastus Medialis
ORIGIN: anterior to lesser trochanter of femur and linea aspra
INSERTION: tibial tuberosity (anterior)
INNERVATION: femoral nerve
ACTION: extensor of knee
Vastus Lateralis
ORIGIN: below greater trochanter of femur and linea aspra
INSERTION: tibial tuberosity (anterior)
INNERVATION: femoral nerve
ACTION: extensor of knee
Rectus Femoris
ORIGIN: Anterior inferior iliac spine and above acetabulum
INSERTION: tibial tuberosity (anterior)
INNERVATION: fermoral nerve
ACTION: thigh flexion, knee extension
Vastus Intermedius
ORIGIN: Anterior shaft of femur
INSERTION: aponeurosis blends with quadriceps tendon and inserts on tibial tuberosity (anterior)
INNERVATION: femoral nerve
ACTION: extensor of knee
Adductor longus & brevis
ORIGIN: Inferior pubic ramus
INSERTION: posterior femur (linea aspra)
INNERVATION: Obturator nerve
ACTION: adductor
Adductor magnus
ORIGIN: Inferior pubic ramus around to ischial ramus
INSERTION: linea aspra to above medial condyle of femur
INNERVATION: Obturator nerve & sciatic (tibial)
ACTION: adductor & partial flexor of knee
Gracilis
ORIGIN: Inferior pubic ramus
INSERTION: below medial condyle of tibia
INNERVATION: Obturator
ACTION: adductor
Semitendinosus
ORIGIN: Inferior ischial ramus (tuberosity of ischium)
INSERTION: Inferior pubic ramus
INNERVATION: tibial nerve (from sciatic)
ACTION: Hamstring - hip extension, knee flexion
Biceps Femoris
ORIGIN: Inferior ischial ramus (tuberosity of ischium) (long head), linea aspra (short head)
INSERTION: proximal lateral fibula
INNERVATION: tibial nerve (except short heat - common fibular)
ACTION: Hamstring - hip extension, knee flexion
Semimembrinosus
ORIGIN: Inferior ischial ramus (tuberosity of ischium)
INSERTION: posterior medial condyle of tibia
INNERVATION: tibial nerve (from sciatic)
ACTION: Hamstring - hip extension, knee flexion
Popliteus
ORIGIN: lateral condyle of femur and meniscus
INSERTION: below medial condyle of tibia
INNERVATION: Tibial nerve
ACTION: medial rotation and flexion of knee
Tibialis anterior
ORIGIN: anterior aspect of shaft of tibia/fibula/interosseous membrane
INSERTION: medial cuneiform and base of first metatarsal
INNERVATION: Deep fibular nerve
ACTION: dorsiflexion and inversion
Extensor Hallucis Longus
ORIGIN: anterior aspect of shaft of tibia/fibula/interosseous membrane
INSERTION: distal phalynx and middle phalynx
INNERVATION:
ACTION: big toe extension
Extensor Digitorum Longus
ORIGIN: anterior aspect of shaft of tibia/fibula/interosseous membrane
INSERTION: distal phalynx and middle phalynx
INNERVATION:
ACTION: toes (except big toe) extension
*gives off Fibularis Tertius to base of 5th metatarsal
Medial to Lateral structures of Dorsum of Foot
Timothy has a nasty, dirty toe
Tibialis anterior eHl Artery (anterior tibial / dorsalis pedis) Nerve (deep fibular nerve) eDl fibularis Tertius
Fibularis Longus
ORIGIN: Proximal shaft of fibula, groves cuboid, passes beneath sole of foot
INSERTION: medial cuneiform and base of 1st metatarsal
INNERVATION:
ACTION: eversion of foot
Fibularis Brevis
ORIGIN: Distal shaft of fibula, groves lateral malleolus
INSERTION: base of 5th metatarsal
INNERVATION:
ACTION: eversion of foot
Gastrocnemius
ORIGIN: each condyle of femur
INSERTION: achilles tendon - calcaneus of heel
INNERVATION:
ACTION:
Soleus
ORIGIN: proximal tibia and fibula w/ arch for neurovascular bundle
INSERTION: archilles tendon - calcaneus of heel
INNERVATION:
ACTION:
Flexor Digitorum Longus
ORIGIN: Shaft of tibia, fibular and interosseus membrane
INSERTION: 4 toes (2nd - 5th metatarsals)
INNERVATION:
ACTION:
Flexor hallucis Longus
ORIGIN: Shaft of tibia, fibular and interosseus membrane
INSERTION: 1st metatarsal (big toe)
INNERVATION:
ACTION:
Tibialis Posterior
ORIGIN: Shaft of tibia, fibular and interosseus membrane
INSERTION: medial cuneiform and base of 1st metatarsal
INNERVATION:
ACTION: Plantar flexion and inversion
Structures from medial malleolus to calcaneus
Tom Dick and Very Naughty Harry
Tibialis posterior fDl Artery (posterior tibial artery) Vein (vena comitantes) Nerve (tibial nerve) fHl
Tibia & Fibula
TIBIA Weight bearing Condyles Intercondylar eminence Tibial tuberosity Soleal line Medial Malleolus
FIBULA Non-weight bearing, muscle attachment Head Shaft Lateral Malleolus
SUPERIOR JOINT:
Synovial - anterior & posterior ligaments
INFERIOR JOINT: Fibrous prevents separation - anterior, posterior, and interosseous ligaments malleolar mortise (oblique angle) - inferior transverse ligament
Bones of foot (posterior to anterior)
Calcaneus
Talus
Navicular
Cuboid
Cuneiforms (medial, intermediate, lateral)
Metatarsals (5)
Phalanges (distal, proximal, middle - except hallux)
+ sesamoid bones - under metatarsals
+ accessory bones - unfused centres of ossification
Lumbar Plexus
Ventral rami L1-L4
Within Psoas Major
From Lateral Border:
Ilioinguinal and iliohypogastric (L1)
Lateral cutaneous nerve of thigh (L2,3)
Femoral nerve (L2,3,4)
Onto Anterior Surface
Genitofemoral (L1,2)
- L1 is femoral branch
- L2 is genital branch
From medial border
Obturator (L2,3,4)
*L5 forms lumbosacral trunk and joins with sacral plexus
Iliohypogastric & Ilioinguinal nerve
From Lumbar Plexus within Psoas
L1
Slip in between Transversus Abdominus and Internal Oblique and track around to supply anterior abdominal wall
Lateral Cutaneous Nerve of Thigh
From Lumbar Plexus within Psoas
L2,3
Swings wide and tucks under beginning of inguinal ligament.
Supplies thigh and skin down lateral side of thigh
Can be compressed during pregnancy = numbness and tingling.
Femoral Nerve
From Lumbar Plexus within Psoas
L2,3,4 posterior divisions
Emerges and tucks into gutter between iliacus and psoas
Runs under inguinal ligament (lateral to artery, vein, lymph)
Divides into terminal branches distal to ligament (2.5cm)
MOTOR to extensors (quads, sartorius, pectineus)
SENSORY to anteromedial thigh, knee, leg, ankle (up to but not beyond 1st metatarsal) via Anterior Cutaneous Branches and Saphenous Nerve
Articular branches to hip and knee
Genitofemoral Nerve
From Lumbar Plexus within Psoas
L1 - femoral branch, supplies area of skin beow middle of inguinal ligament
L2 - genital branch, supplies spermatic cord
Obturator Nerve
From Lumbar Plexus within Psoas
L2,3,4 anterior divisions
Crosses pelvic brim
Runs along lateral wall of pelvis into obturator canal and into medial compartment of thigh
- anterior branch (between longus and brevis)
- posterior branch (between brevis and magnus)
MOTOR to adductors (gracilis, longus, brevis, magnus, pectineus)
SENSORY to peritoneum and medial patch above knee (inflammation of peritoneum can refer pain here)
Articular branches to hip
Sacral Plexus
Lumbosacral Trunk (L5) joins S1-4 on piriformis
Visceral branches to pelvic viscera
Somatic branches to walls and floor of pelvis
Somatic branches that exit pelvis with piriformis and supply structures of lower limb
- Sciatic Nerves (L4,5, S1-3)
- Superior and Inferior Gluteal Nerves
- Posterior Cutaneous Nerve of Thigh
Sciatic Nerve
L4,5, S1-3 anterior and posterior divisions
Exits pelvis via Greater Sciatic Foramen
Emerges beneath Piriformis in gluteal region (posterior to hip)
Descends posterior to thigh
Divides at apex of popliteal fossa
- Tibial
- Common Fibular
MOTOR to hamstrings (tibial except SHOB - common fib.)
SENSORY via terminal branches only
Articular branchess to hip
Tibial Nerve
L4,5, S1-3 anterior divisions (sciatic)
Vertical descent through popliteal fossa, beneath fibrous arch of soleus, descends on tibialis posterior, posterior to medial malleolus onto sole of foot, gives off medial and lateral plantar nerves
- lateral plantar (similar to ulnar) - supplies lateral 1.5 toes and all intrinsic muscles of sole of foot
- medial plantar (similar to median) - supplies medial 3.5 digits
MOTOR to muscles of posterior leg and sole of foot
SENSORY to posterior leg (sural nerve), heel, and sole of foot (medial calcaneal, medial and lateral plantar)
- lateral plantar (similar to ulnar) - supplies lateral 1.5 toes and all intrinsic muscles of sole of foot
- medial plantar
Common Fibular Nerve
L4,5, S1-3 posterior divisions (sciatic)
Runs medial to biceps femoris, superficial to lateral head of gastrocnemius, winds around neck of fibula onto fibularis longus and gives off terminal branches
- deep fibular nerve (descends deep to EDL, anterior to interosseous membrane, beneath extensor retinaculum, onto dorsum of foot)
- superficial fibular nerve (descends in lateral compartment)
Deep Fibular Nerve
MOTOR to anterior compartment of leg and Extensor Digitorum Brevis
SENSORY to 1st toe cleft
Articular branches to ankle and foot
Superficial Fibular Nerve
MOTOR to lateral compartment of leg (Fibularis longus and brevis)
SENSORY to lower lateral leg and dorsum of foot
Posterior Cutaneous Nerve of Thigh
Branch from sacral plexus
SENSORY to posterior thigh
Leg Myotomes
- Hip Flexion/Extension
- Knee Extension/Flexion
- Ankle Dorsiflexion/Plantarflexion
- Foot Inversion/Eversion
- Big to Dorsiflexion/Plantarflexion
HIP
L2,3 / L4,5
KNEE
L3,4 / L5,S1
ANKLE
L4,5 / S1,2
FOOT
L4 / L5, S1
BIG TOE
L5, S1 / S1, S2
Branches of Arteries of Lower Limb
External Iliac
Femoral
- Profunda femoris
- Popliteal
Popliteal (under adductor hiatus)
- Genicular anastamoses
- Anterior Tibial
- Posterior Tibial
Anterior Tibial
- Dorsalis Pedis (pierces first interossei)
Posterior Tibial (Inferior border of popliteus)
- Fibular
- Medial and Lateral Plantar (under flexor retinaculum)
Lateral Plantar artery
- swings wide and creates deep plantar arch - completed by termination of dorsalis pedis from dorsum of foot)
Veins of Lower Limb
Greater Saphenous Vein (acompanies saphenous nerve)
- from dorsal venous arch
- anterior to medial malleolus
- up medial side of leg
- hands breadth behind patella
- medial thigh
- through saphneous opening emptying into femoral vein
Superficial Saphenous Vein
- from dorsal venous arch
- posterior to lateral malleolus
- posterior leg
- pierces deep facia and joins paired vena comitantes of anterior and posterior tibial arteries to become popliteal vein
(vertical) Superficial inguinal lymph drain lower limb
(horizontal) Superficial inguinal lymph drain abdominal wall, external genitalia, and anal canal
Drain to deep lymph (following arteries)
Superficial lymph follows veins
Structures of Dorsum of the Foot
- EXTENSOR DIGITORUM BREVIS
- arises from superolateral part of calcaneus, deep to long extensor tendons, joins EDL tendons - EXTENSOR HOODS
- Triangular, apex inserts into base of distal phalynx, centre of each hood attaches to sides of middle phalynx and wrapped over metatarsalphalyngeal joint - DEEP FIBULAR NERVE
- Supplies EDB (as well as extensors), sensory to webbed space between 1st and 2nd toes - DORSALIS PEDIS ARTERY
- name change of anterior tibial artery
- gives off arcuate artery laterally which gives off metatarsal and digital arteries
- continues to first web space and gives off deep plantar artery which dives through first dorsal interosseous and completes deep plantar arch
Layers of Sole of Foot
Plantar Aponeurosis
- thickening of deep fascia from medial process of calcaneal tuberosity dividing into five slips
- vertical septa divide plantar aspect into medial, deep, lateral compartments
- Short
- abductor digiti minimi & abductor hallucis insert into base of proximal phalynx
- Flexor digitorum brevis splits and inserts into base of middle phalynx (FDL passes through and inserts distally)
- arise from calcaneal tuberosity, aponeurosis and septa
- assist and maintain arches
- neurovascular structures run here. - Long
- FDL, FHL
- lumbricals on medial side of toes and insert into expansion of FDL
- quadratus plantae - arises from two heads on calcaneus and inserts into border of FDL (optimises function and straightens line of pull) - Short
- short flexor for each of the big (flexor hallucis brevis) and little toes (flexor digiti minimi brevis), and an adductor hallucis - Short
- interossei in intermetatarsal spaces
- abduction/adduction around plane of second digit
- 3 plantar adducting (PAD)
- 4 dorsal abducting (DAB)
- insertions of fibularis longus and tibialis posterior into base of first metatarsal
Demarcation of false pelvis from true pelvis
iliopectineal line demarcates false pelvis above from true pelvis below
What structures seperate the greater and lesser sciatic foramen?
ischial spine, sacrospinous ligament, and sacrotuberous ligament, seperates greater and lesser sciatic foramen
Levator Ani
pubococcygeus and iliococcygeus (not ischiococcygeus)
Forms pelvic floor
Closes off pelvic outlet
LATERAL ORIGIN
- internal aspect of body of pubis
- along side wall of pelvis (across half of obturator internus fascia)
- to ischial spine
INSERTION
- raphe (tip of coccyx to anorectal junction)
large opening anteromedially for passage of viscera to perineum
ACTIONS:
lifts pelvic floor / anus,
w/ contraction of diagphram causes increased intraabdominal pressure and compression of pelvic contents and promotes evacuation
slings are vital for support of pelvic viscera (prolapse)
helps rotate babies head during birth
Pubococcygeus
- part of levator ani (anterior fibres)
- origin: internal aspect of body of pubis
- insertion: anococcygeal raphe
(also includes puborectalis and pubovaginalis/prostaticus slings)
overlaps iliococcygeus
Puborectalis
- anterior fibres of pubococcygeus (levator ani)
- origin/insertion: internal aspect of body of pubis
- sling extending around and blending with anorectal junction
- important for fecal continence
Pubovaginalis/Puboprostaticus
- most anterior fibres of pubococcygeous (levator ani)
- origin/insertion: internal aspect of body of pubis
- slings around vagina / prostate
Iliococcygeus
- part of levator ani (posterior fibres)
- origin across half of obturator internus fascia to ischial spine
- insertion: anococcygeal raphe
Ischiococcygeus
- origin coxxyx/sacrum
- insertion ischial spine
(same as sacrospinous ligament) - used by dogs to wag tail
- closes posterior part of pelvic floor
Parietal fascia of pelvic cavity
- covers piriformis, obturator internus, and levator ani
- continuation of fascia of anterior abdominal wall (Fascia Transversalis)
- continuation of fascia of posterior abdominal wall (Fascia iliacus)
Visceral fascia of pelvic cavity
- continous with extraperitoneal fat layer of abdomen
- many thickenings (called ligaments) which are condensations of fascia around neurovascular structures
- significant support structures to pelvic viscera
female: rectouterine ligament
lateral cervical (cadinal) ligament
lateral vesical ligament
pubovesical ligament
Epiphysis of pelvis
iliac crest
ASIS & AIIS
ischial tuberosity
pubic tubercle
acetabulum
- common sites of avulsion fractures (tendon stronger than bone)
- length of time epiphysis stays open determins pelvic shape
Boundaries of Pelvic Inlet
- pubic symphysis/crest/tubercle
- pectineal lineof pubis
- arcuate line of ilium
- sacral alar joint
- body of sacrum (promotary)
Boundaries of Pelvic Outlet
- inferior margin of pubic symphysis
- ischial tuberosity
(sacrotuberous ligament) - tip of coccyx
(can be broken up into anterior - urogenital, and posterior - anal, triangles of the perineum)
Perineal Pouches
- superficial and deep pouches
- seperated by perineal membrane
- superficial and deep transverse perineal muscles in posterior edge between perineal body and ischial tuberosities
- perineal body (site of muscle attachment in posteromedial perineal membrane)
- deep pouch contains sphincters (external urethral, sphincter urethrovaginalis)
- roots of external genitalia attach to external surface of perineal membrane
Ligaments of Pelvis
- interosseous sacroiliac
- iliolumbar
- sacrotuberous
- sacrospinous
Boundaries of pelvic plane of least dimensions
- S4 vertebra
- through ischial spine
- inferior part of pubis
“Pelvic Pain Line”
above = sympathetic visceral afferents nerves (above L1)
below = parasympathetic visceral afferents (S2,3,4)
Examples of secondary cartilagenous joints
pubic symphysis
intervertebral discs
manubriosternal
(all have a disc)
Obturator Foramen
- covered by obturator membrane
- gives rise to obturator internus internally
- gives rise to obturator externus externally
- obturator nerve, artery, vein pass through obturator canal
Greater Sciatic Foramen
- bounded by sacrospinous and sacrotuberous ligamennts
- sciatic nerve
- pudendal nerve, internal pudendal artery (out)
Lesser Sciatic Foramen
- bounded by sacrospinous and sacrotuberous ligamennts
- pudendal nerve, internal pudendal artery (in)
Pudendal Nerve
- branch of sacral plexus
- arises from S2,3,4
- exits greater sciatic foramen with piriformis
- curls behind ischial spine
- runs in pudendal canal on obturator internus
- enters lesser sciatic foramen
branches: - inferior rectal nerve (to external anal sphincter)
- perineal nerve (supplies structures in urogenital triangle - motor and cutaneous including genitals)
Broad Ligament
parietal peritoneum draping over uterine (fallopian) tubes and extending to side wall of pelvis
contains proper ovarian ligament attaching to ovary on posterior side of broad ligament
suspensory ligament holds ovary in place (inside peritoneum)
Pelvic Shapes
50% - Gynaecoid
30% - Android
20% - Anthropoid
2% - Platypelloid
Anteversion
Anteflexed
Anteversion
- curvature related to other structure (i.e. uterus & vagina)
Anteflexed
- curvature within organ (i.e. uterus)
Bladder
shaped like pyramid tipped forward (apex towards pubic bone)
detrusor muscle in wall of bladder (contraction = urination)
- when full can push up peritoneum 8-10cm (suprapubic aspirate)
base of bladder has smooth triangular region - trigone - entry/exit at each point of the triangle (ureters, urethra)
Uterus
fundus, body, cervix (internal/externial uterine opening) fallopian tubes (intramural, isthmus, ampulla, infundibulum, fimbria) cervix stabilized by lateral cervical (cardinal) ligament
Structures associated with bladder (male)
- vas deferens (originates at epididymus, ascends as component of spermatic cord in inguinal canal, through deep ring, passes along side wall of pelvis, along lateral bladder, above ureter, to posterior bladder)
- seminal vesicles (coiled tubules, join w/ vas deferens to form ejaculatory duct and empty into prostate/urethra)
- prostate (between neck of bladder and levator ani, above urogenital diaphragm, anterior to rectum)
Structures associated with bladder (female)
- uterus (anteverted and anteflexed)
- uterine artery (from internal iliac artery, to uterus, passes over ureter)
Lowest point in female peritoneum
- recto-uterine pouch (pouch of douglas)
- can palpate or aspirate free fluid via vagina
Rectum
beneath peritoneum, does not have mesentary
no teniae coli - span to become one longitudinal muscle coat
situated in concavity of sacrum
Upper Anal Canal
upper 2/3 of anal canal divided by pectinate line
lined by mucosa
supplied by superior rectal artery (inferior mesenteric from abdominal aorta)
venous drainage to portal system
innervated by autonomic nerves (dull, poorly localised pain)
internal sphincter (thickening in smooth muscle wall under autonomic innervation)
Lower Anal Canal
lower 1/3 of anal canal divided by pectinate line
lined by skin
supplied by inferior rectal artery (internal iliac branch)
venous draining to IVC
innervated by pudendal somatic nerves (sharp, intense, well localised)
deep external sphincter (fuses with puborectalis)
superficial external sphincter (attached anteriorly to perineal body and tip of coccyx)
subcutaneous external sphincter (immediately beneath skin)
Blood supply of Pelvic Structures
FROM ABOVE:
- ovarian from aorta (uterus, fallopian tube, artery)
- superior rectal arteries (terminal inferior mesenteric) from aorta
FROM SIDES:
- anterior branches of internal iliac from side wall
- superior vesical arteries (paired)
- inferior vesical arteries (male - prostate and vas deferens)
- uterine artery (cervix)
- vaginal artery (female - vagina)
- middle rectal arteries
Branches of Internal iliac artery
Arises at pelvic brim opposite sacroiliac joint
Posterior division (parietal branches only)
Anterior division (to visceral and parietal)
- superior vesical arteries (paired)
- inferior vesical arteries (male - prostate and vas deferens)
- uterine artery (female - in lateral cervical ligament, over ureter, gives off cervical and vaginal branches, turns upwards within broad ligament alongside uterus, along fallopian tube and and meets ovarian artery)
- vaginal artery (female - vagina)
- inferior rectal artery (anal canal)
Male vs Female pelvis
MALE Thick and heavy Heart Shaped Narrow inverted v greater sciatic notch acute subpubic arch large acetabulum round obturator foramen Larger overall
FEMALE Thin and light Transverse oval 90 degree greater sciatic notch obtuse subpubic arch small acetabulum oval obturator foramen true pelvic inlet broader/rounder
At what level do each of the following structures perforate the diaphragm?
- aorta
- oesophagus
- IVC
AORTA - T12
OESOPHAGUS - T10
IVC - T8
