Week 1 - Severson Flashcards
What layers make up the scalp?
S: Skin C: Connective tissue (superificial fascia) A: Aponeurosis L: Loose connective tissue P: Pericranium/Periosteum
In what layer are the major blood vessels and nerves of the scalp?
Connective tissue layer (superficial fascia)
Why is bleeding so perfuse with scalp injuries?
Because they are tethered open by surrounding connective tissue. The blood vessels also anastomose freely and hemorrhage cannot be controlled by compressing any single vessel.
What are the major dangers of scalp wounds?
Infectious processes may arise subcutaneously in the scalp and progress intracranially via the Diploic/Emissary veins that drain into the dural venous sinuses (eventually could involve the meninges –> meningitis).
What do the areas of the fontanelles become later in life?
Anterior fontanelle –> Bregma Posterior fontanelle –> Lambda
The superficial veins of the scalp connect to the dural sinuses by means of the _______?
Emissary veins
What layer of the scalp are the diploic veins are located in?
Between the two bony layers of the skull.
The superficial temporal arter is a terminal branch of the ______?
External carotid artery
The auriculotemporal nerve supplying the temporal region of the head is a sensory branch of the _________ nerve.
Mandibular division (V3) of the Trigeminal nerve
What is the pericranium and endocranium?
Pericranium = outer periosteum Endocranium = inner periosteum (periosteal layer of dura)
What are the paranasal sinuses and where are they located?
- Frontal sinuses - above bilateral eyebrows 2. Ethmoid sinuses - under frontal lobe/below cristal galli area 3. Sphenoid sinuses - under sella turcica 4. Maxillary sinuses - above teeth/below nose bilaterally
Define the 3 cranial fossae and their contents.
- Anterior cranial fossa - frontal lobe –> lesser wings 2. Middle cranial fossa - greater wings –> petrous part (ridge) 3. Posterior cranial fossa - jugular foramen –> occipital lobe/cerebellum
Where are the ventricles of the brain located?
- Lateral ventricles - under Corpus Callosum 2. Third ventricle - Thalamus & Hypothalamus 3. Fourth ventricle - Anterior to Cerebellum
What are the two major blood vessels supplying the brain?
- Internal Carotid Arteries 2. Vertebral arteries
How does the newborn skull differ from that of the adult?
-Cranium larger than face -No dipole or mastoid process -Fontanelles where fibrous tissue and cartilage connect the frontal, parietal, and occipital skull bones (fuse ~2yoa)
What are the major divisions of the brain?
- Cerebral hemispheres 2. Brainstem 3. Cerebellum
The middle meningeal artery enters the cranial cavity through the _____?
Foramen Spinosum
The arachnoid granulations that extend into the dural sinuses are formed by the _____ layer.
Arachnoid layer of the meninges
Which layer of the dura is responsible for the formation of the dural reflexions?
Meningeal layer
Where are the dural sinuses are located?
in or between the meningeal and the periosteal layers of the dura
Where are the cerebral veins located?
Pial membrane
What vessel is usually ruptured in a patient that has a subarachnoid hemorrhage?
Cerebral artery
What dural reflexion separates supratentorial structures from posterior fossa structures?
Tentorium cerebelli
CN I
Name
Sensory/Motor –> Innervation
Cell body location
Course
Olfactory - sensory - Olfactory epithelium
Cell body –> Olfactory epithelium
Through cribiform plate of ethmoid.
CN II
Name
Sensory/Motor –> Innervation
Cell body location
Course
Optic - sensory - retina (bipolar cells)
Cell body –> ganglionic layer of retina
From orbit through optic canal to optic chiasm, optic tract
CN III
Name
Sensory/Motor –> Innervation
Cell body location
Course
Oculomotor - motor - 4 eye muscles
Cell body –> oculomotor nucleus
Superior Orbital fissure.
CN IV
Name
Sensory/Motor –> Innervation
Cell body location
Course
Trochlear - motor - superior oblique eye muscle
Cell body –> trochlear nucleus
Superior orbital fissure.
CN V
Name
Sensory/Motor –> Innervation
Cell body location
Course
Trigeminal - sensory/motor
V1 - Ophthalmic - sensory - face, nose, mouth, supratentorial dura
V2 - Maxillary - sensory - proprioception from head, TMJ, and tooth sockets
V3 - Mandibular - motor - muscles of mastication, tensors tympani and veli palatini, mylohyoid, anterior digastric
CN VI
Name
Sensory/Motor –> Innervation
Cell body location
Course
Abducens - motor - lateral rectus eye muscle
Cell body –> abducens nucleus
Superior orbital fissure.
CN VII
Name
Sensory/Motor –> Innervation
Cell body location
Course
Facial - motor/sensory - muscles of facial expression, stylohyoid, posterior digastric, stapedius, glands of nose, palate, lacrimal gland, submandibular sublingual glands, taste buds, external auditory meatus, and skin on back of ear.
Course: Internal acoustic meatus to exit stylomastoid foramen, greater petrosal to pterygopalatine ganglion, chorda tympani to submandibular ganglion.
Through what passageway does the facial nerve exit the skull?
Stylomastoid foramen
Through what passageway does the facial nerve exit the cranial cavity?
Internal auditory (acoustic) meatus
Which of the following structures is NOT found in the posterior fossa? A. Cerebellum B. Cerebrum C. Facial nerve D. Midbrain E. Pons
B. Cerebrum
What blood vessel is most likely to produce an epidural or extradural hematoma?
Rupture of meningeal artery.
Between what two structures is an epidural hematoma confined?
bone and dura (lens shape on radiography).
What blood vessel is most likely to produce a subdural hemorrhage?
Rupture of a cerebral vein.
Between what two structures is an subdural hematoma confined?
dura & arachnoid membranes (blood accumulates in subdural space on radiography)
What blood vessel is most likely to produce a subarachnoid hemorrhage?
Rupture of a cerebral artery.
Between what two structures is an subarachnoid hematoma confined?
arachnoid membrane & the pia
What is the pterion? What is it’s significance?
-region where frontal, parietal, temporal and spenoid join together -considered weakest part of the skull
Where is the location of the limbic lobe?
Medial aspect of each hemisphere, completely surrounding the corpus callosum and diencephalon.
What does the limbic lobe consist of?
-Septal or subcallosal area -Clingulate gyrus -Isthmas of the cingulate gyrus -Parahippocampal gyrus -Hippocampal formation (Subiculum, Dentate gyrus, & Hippocampus)
What is the function of the limbic lobe?
-Anterior part: Involved in emotional behavior & homeostasis -Posterior part: Involved in the cortical processes of learning and memory (consolidation of memories - declarative)
Where is the Olfactory cortex located?
Piriform cortex (area covering part of amygdaloid nucleus) + Lateral entorhinal cortex (small anterior region of the anterior parahippocampal gyrus)
What is the function of the Olfactory Cortex?
-Perception of odors -Discrimination and identification of odors
Where is the Insular cortex?
Buried in the depths of the lateral sulcus; covered by the frontal, parietal, and temporal opercula; lateral to the basal ganglia (lentiform nucleus); continuous with the anterior perforated substance on the ventral surface of the brain in the area known as the limen insulae.
What is the function of the Insular Cortex?
Serves to integrate visceral input: -olfactory, gustatory, and general sensory info -AKA: smell, taste, pain, thermal
What is the major blood supply of the Internal Capsule?
-Central/ganglionic branches of the middle cerebral artery
What are projection neurons?
Axons projecting TO or FROM the cerebral hemispheres.
What are the two terminal branches of the external carotid artery?
- Facial artery 2. Superficial temporal artery
What are several major branches of the maxillary artery and through what foramina do they pass?
- Inferior alveolar artery 2. Middle (and accessory) Meningeal artery - enters through foramen spinosum 3. Infraorbital and posterior superior alveolar arteries 4. Muscular branches (e.g. masseteric, temporal, pterygoid)
Through which fissure does the maxillary artery pass?
Pterygomaxillary fissure
Where does the maxillary artery terminate?
Pterygopalatine fossa (whereafter it divides)
What are the two terminal branches of the maxillary artery?
Sphenopalatine & Descending palatine branches
Where is the pterygoid plexus of veins located?
Surrounds the lateral pterygoid muscle
What anastomotic connections does the pterygoid plexus of veins have with the facial vein and the cavernous sinus?
Communicates with the facial vein via the deep facial vein and with the cavernous sinus through the foramen ovale (spread of infection).
With what bone does the mandible articulate?
Articular surface of the temporal bone