Anatomy Flashcards
What are the layers of the Dura Mater?
Periosteal (outer) and meningeal (inner)
Only has two layers in cranium, in the spine on the meningeal layer is present
What are dural reflections?
Reflections of the meningeal dura from the periosteal dura to form dural sheets which seperate brain regions from each other, they prevent rotation of the brain within the cranial cavity
What is the name of the infolding of dura mater which seperates the cerebrum and the cerebellum?
Tentorium cerebelli
Name the 5 layers of the scalp
1- Skin
2- Connective tissue
3- Aponeurosis (frontalis to occipitalis)
4- Loose areolar connective tissue (Danger- Infection can spread via emissary veins into cranium)
5- Pericranium
What are the ant and post borders of the parotid gland, where does it enter the oral cavity?
Ant- Mandible ramus and mastoid process
Post- Sternocleidomastoid
Into oral cavity- Parotid duct through buccinator
Which nerve splits into its branches in the parotid gland, what are the names of these brances? (5)
Facial Nerve
Branches: Temporal Zygomatic Buccal Mandibular Cervical
What provides autonomic supply to the parotid gland?
PNS- Glossopharyngeal nerve = Increased salivation
SNS- Cervical nerves = Decreased salivation
What is the action of the occipitofrontalis muscle?
Raises eyebrows and wrinkles forhead
What is the action of the orbicularis oculi muscle? What nerve supplies it?
Scrunches the eyes (temporal branch of CNVII)
What is the action of the levator palpabrae superioris muscle, what nerve supplies it?
Raises eyelid (occulomotor nerve)
What is the action of the orbicularis oris muscle, what nerve supplies it?
Puckers lips (buccal branch of CNVII)
What is the action of the zygomaticus major muscle, what nerve supplies it?
Raises corner of mouth- smile (Zygomatic branch CNVII)
What is the action of the zygomaticus minor muscle, what nerve supplies it?
Elevates upper lip (Buccal branch of CNVII)
What is the action of the platysma muscle, what nerve supplies it?
Draws corner of mouth inferiorly and wrinkles skin of neck (Cervical branch of CNVII)
(Runs over sternocleidomastoid)
What are the 4 muscles of mastication and what nerve innervates them?
Temporalis, Masseter, Medial/ Lateral Pterygoids (Mandibular Branch of Trigeminal CN V)
What is the origin, insertion, action and innervation of the temporalis muscle?
O: Temporal line on parietal bone
I: Coronoid process of mandible
A: Elevates and retracts mandible
N: Mandibular branch of CN V
What is the origin, insertion, action and innervation of the masseter muscle?
O: Zygomatic arch and maxilla
I: Coronoid procress and ramus of mandible
A: Elevates mandible
N: Mandibular branch of CN V
What is the origin, insertion, action and innervation of the medial pterygoid muscle?
O: (Deep head)- Lateral pterygoid plate (Super head)- Pyramidal process of palatine bone
I: Medial angle of mandible
A: Elevates mandible
N: Mandibular branch of CN V
What is the origin, insertion, action and innervation of the lateral pterygoid muscle?
O: Greater wing of sphenoid
I: Condyloid process of mandible
A: Depresses, protracts and laterally moves mandible
N: Mandibular branch of CN V
Which muscle of mastication depresses, protracts and laterally moves the jaw?
Lateral pterygoid
Name two proximal tributaries of the femoral vein
Great saphernous and deep femoral veins
What are the boundaries of the femoral triangle?
Sup: Inguinal ligament
Med: Adductor longus
Lat: Sartorius
What are the contents of the femoral triangle?
Femoral art/vein/nerve/sheath
Inguinal LN’s
What is the action of the quadriceps muscle?
Which muscles contribute to it?
Which nerve supplies it?
The great extensor of the knee
Rectus femoris + 3 vastus muscles (lat/med/intermed)
Femoral nerve
Do not confuse with quadratus femoris (on post thigh)
What nerve supplies the anterior compartment of the thigh?
Femoral nerve (from lumbar plexus L2 to L4)
What nerve supplies the posterior compartment of the thigh?
Sciatic nerve (tibial part except biceps short head which is common fibular part)
What nerve supplies the medial compartment of the thigh?
Obturator nerve (from Lumbar plexus L2 to L4)
What is the adductor canal?
A a tunnel in the middle thigh which runs from the apex of the femoral triangle, to the adductor hiatus in the adductor magnus muscle. It is bounded by sartorius (ant), vastus medialis (lat) and the adductors (post/med)
What is the hamstring?
Made up of 5 muscles/ tendons: Biceps femoris (long and short head), semimembranous, semitendinosus and a portion of adductor magnus
What is the medical name for the hip?
Coxa
What type of joint is the acetabulofemoral (hip) joint? What are the articular surfaces covered with?
A synovial ball and socket joint
Articular surfaces covered with hyaline cartilage
What is the Acetabular labrum?
A ring of cartilage which surrounds the acetabulum
In the ventral horn of the spinal cord:
a) What colour is the matter?
b) What cells are found there?
a) Grey matter
b) Lower motor neuron cell bodies
Which skull bones are joined by the lambdoid suture?
Connects the parietal and occipital bones
NB it doesn’t close til age 60
What nuclei are involved in the RAS?
Midbrain reticular formation Mesencephalic nucleus Thalamus intralaminar nucleus Dorsal hypothalamus Tegmentum
What is the Pterion and what is its clinical significance?
Meeting of several skull sutures, a common site of fracture, resulting in rupture of the middle meningeal artery and extradural haematoma
Where is the motor cortex found?
Precentral gyrus (posterior frontal lobe)
Where is the sensory cortex found?
Postcentral gyrus (anterior parietal lobe)
What are the different shapes of your menisci in the knee, what are they made from and what is their purpose?
Medial: Cresent shaped (most commonly torn)
Lateral: Circular shaped (deeper articular surface)
Made of semilunar fibrocartlidge, used for shock absorbtion
What type of joints make up the bones of the foot?
All plane synovial except:
Interphalangeal joints- Hinge
Metatarsal/ phalangeal joints- Condylar (aka saddle, allow ab and adduction)
What is a bursa and what 4 bursa are found in the knee?
Sac of synovial fluid + fat which cushions:
1) Pre patellar 3) Suprapatellar
2) Infrapatellar 4) Popliteal
How many vertebrae/ nerves do you have in each spinal region?
Cervical: 7V 8N Thoracic: 12V 12N Lumbar: 5V 5N Sacral: 5V 5N Coccygeal: 3/4V - 1N
What are spinal primary curves?
Concave anterior and reflex shape of foetus (Thoracic and sacral)
What are spinal secondary curves?
Cervical develops at 3-9months (hold head up)
Lumbar develops at 12-18months (walking)
What is the name for the gaps between schwann cells?
Nodes of ranvier
What is the origin of the sciatic nerve?
From nerve roots L4-S3, fibres unite in front of the piriformis muscle
What is the course of the sciatic nerve?
Forms on piriformis, goes through greater sciatic foreamen, in post compartment of thigh, to popliteal fossa and then behind adductor magnus where it divides into:
a) Tibial part (L4-S3) b) Common fibular part (L4-S2)
Which area’s are innervated by the sciatic nerve?
Tibial: (Motor)- All post lower leg (except biceps short)
(Sensory)- Sole of foot
Common Fibular: (Motor)- All ant/ lat lower leg
(Sensory) Dorsal surface of foot
SCIATIC: All posterior thigh
Which is the only muscle in the posterior lower leg to be innervated by the sciatic nerve?
Short head of biceps femoris
What nerve innervates the sole of the foot?
Tibial branch of sciatic nerve
What is the name of the outer part and inner part of an intervertebral disc?
Outer: Annulus fibrosus
Inner: Nucleus pulposus (mucoprotein gel)
What is the lumbar cistern region?
From conus medularis (end of spinal cord- L1/L2) to
around S2. A cistern is a swelling (of the sub-arachnoid space)
LP usually done at L4/L5
Describe the path the needle would take in an LP
Through skin, 1st give indicates through ligamentum flavum, second give indicates through dura mater so now in sub-arachnoid space
How much circulating CSF do you have and how much do you produce each day?
Circulating: 150ml
Produced each day: 500ml
Where are the dural venous sinuses located and what do they do?
Between the endosteal and the meningeal layers of the dura mater. They do venous drainage of the cranium and drain into the IJV’s
How is CSF reabsorbed by the dural venous sinuses?
Small projections of arachnoid mater into the dura allow CSF from the subarachnoid space to drain into the dural venous sinuses
How does the pia mater differ to the other two meningeal layers?
Very highly vascularised, with some vessels sticking through to supply the brain. Also very thin, sticks to brain and follows contours of gyri and fissures
What point is the lateral attachment for the inguinal ligament?
Anterior superior iliac spine
What bony projection is between the greater and lesser sciatic notches?
Ischial spine
Which artery supplies the occipital lobe?
Posterior cerebral artery
Which artery supplies the frontal lobe and sup/ med parietal lobes?
Anterior cerebral artery
Which area’s are supplied by the basilar artery? Which arteries form the basilar artery?
Brain stem and cerebellum
Created by confluence of L/R vertebral arteries
Which blood vessel supplies brocha’s and wernicke’s area’s?
Middle cerebral artery
Where does the middle cerebral artery supply?
Most of the lateral hemispheres (including brocha’s, wernicke’s, basal ganglia and internal capsule)
MOST COMMON site of stroke
Cranial sutures are held together by connective tissue called?
Sharpneys fibres
What bones meet at the pterion (pteryion)
Frontal, parietal, temporal and sphenoid
What is the pterygoid plexus?
Venous plexus which receives blood from the middle meningeal veins and drains into the maxillary vein. Located between nose and ear, just above the top lip
What bones does the squamous suture join?
Parietal and temporal
What does the coronal suture seperate?
Frontal and parietal bones
What is the name for the sheet of dura mater which runs in the longitudinal fissure, separating the L/R hemispheres
Falx cerebri
What is the name for the in folding of dura mater which separates the two halves of the cerebellum hemispheres
Falx cerebelli
Which in folding of the dura mater contains a hole for the pituitary stalk?
Diaphragm sellae
How is the dura mater drained venously?
Venous sinuses inbetween the layers of the dura mater drain into the internal jugular veins
What anchors the pia mater to the surface of the brain?
Processes of astrocytes
What are arachnoid trabeculae?
Projections of arachnoid mater which go into the pia mater
Where is the CSF contained?
In the subarachnoid space between arachnoid and pia mater
What happens to the dura mater at the end (caudal) of the spinal cord?
Blends with filum terminale to form the coccygeal ligament
What is significant about the subdural space?
In a living person there is no actual space there, the inner DM touches the outer AM
What is the conus medullaris? At what vertebral level is it found?
Tapered lower end of spinal cord (L1/L2)
Arachnoid mater ends here
What is the filum terminale?
Thread of fibrous tissue going down from the conus medullaris. It’s a continuation of the pia matter
What is the dural sac?
A continuation of the dura mater inferior to the conus medullaris, it contains the cauda equina and filum terminale (and the lumbar cistern)
What is the name of the structure which separates the two lateral ventricles?
Septum pellucidum
Where would the third ventricle be found?
In the diencephalon
What is the role of the cerebral aqueduct?
Runs through midbrain to connect 3rd and 4th ventricles
Where would the 4th ventricle be found?
Behind the pons, anterior to the cerebellum
How is CSF produced?
In the choroid plexus by ependymal cells
Name 3 functions of CSF
Cushions, supports and suspends, transports nutrients, messengers and waste
How is CSF returned to the venous system?
Via arachnoid villi (projections of arachnoid mater into dura mater)- Into the dural venous sinuses
At what level do the internal carotid arteries split from the common carotids? Where does the ICA enter the skull?
Leaves common carotid at C3
Enters skull through foreamen lacerum
At what level do the vertebral arteries arise from the the subclavian arteries? Where do they enter the skull?
Leave subclavian at C6
Enter skull through foreamen magnum
From which vessels does the spinal cord receive its blood supply?
Ant spinal artery x1 (central)
Posterior spinal arteries x2 (lateral)
Supplemented by radicular arteries
What is the venous drainage to the spinal cord?
In subarachnoid space: 1- Post spinal vein (in centre) 2- Posteriolateral spinal vein (x2) 3- Anterior spinal vein Outside dura mater: Internal vertebral venous plexus
Through what does the internal carotid artery enter the middle cranial fossa?
Carotid canal
What is the difference between emissary veins and normal veins?
Emissary veins have no valves
Which nerve innervates the dura mater?
Middle meningeal branch of V3 (Mandibular)
What are the three cellular levels of the cerebellar cortex?
Bottom- Granular
Middle- Purkinje
Top- Molecular
What is the name for the opening between the lips?
Oral fissure
What is the vestibule of the mouth?
Space between the gums/ teeth and lips/ cheeks
parotid duct from parotid gland empties in vestibule by 2nd molar tooth
