Lecture one-Dr. Houston Flashcards
1
Q
What is the neurocranium?
A
(cranial vault)
* Bony case of the brain and cranial meninges. Dome-like roof, the calvaria (skullcap), and floor or cranial base (basicranium).
2
Q
What is part of the calvaria? What is part of the cranium base?
A
- Calvaria (skullcup): frotnal, part, occipital and temp bone (6-paired bones occurring bilaterally form the calvaria)
- Cranial base: Ethmoid, sphenoid and occipital…15 irregular bones form the cranial base
3
Q
What is the pterion?
A
The pterion is the area of junction of four bones within the temporal fossa.
* temp, sphenoid, frontal and part
4
Q
What is deep to the pterion?
A
middle mengingal artery
5
Q
What is the viscerocranium?
A
Facial skeleton (facial bones)
6
Q
What are the important sutures we should know of the skull?
A
Coronal suture: between frontal and parietal
Sagittal suture: between the two parietal
Lambdoid suture: between occipital and parietal bones
7
Q
For the mouth, what bones is it made up of?
A
- Ant: maxilla bone
- Post: palatine
8
Q
What goes through the external opening of the carotid canal?
A
Internal caratid artery comes through for circle of willis
9
Q
What goes through the foremen magnum?
A
Spinal cord
10
Q
A
11
Q
What is located on the frontal bone?
A
Ethmoid bone which has the cribiform plate (CN1)
12
Q
What is located with the sphenoid bone?
A
- Superior orbital fissure
- Greater wind of sphenoid
- Foramen ovale
- Foramen spinosum
13
Q
What is located on the parietal bone? What goes through here?
A
Internal acoustic meatus -> 2 cranial nerves (vestibular-cochular and facial nerve)
* The foramen lacerum is between the parietal bone and sphenoid bone
14
Q
What is located on the occipital bone?
A
- Jugular foramen
- Hypoglossal canal
- Foramen magnum
15
Q
A
16
Q
- Fracture of the pterion can be what?
- What is the result?
A
- can be life-threatening because it overlies the frontal (anterior) branches of the middle meningeal vessels, which lie in grooves on the internal aspect of the lateral wall of the calvaria
- The resulting epidural hematoma (normally no epidural space)exerts pressure on the underlying cerebral cortex.
17
Q
Untreated middle meningeal artery hemorrhage may cause what?
A
death in a few hours
18
Q
What are the different head fractures a person can get?
A
19
Q
What is a blowout fracture?
A
Indirect traumatic injury that displaces the orbital walls is called a “blowout” fracture.
20
Q
- Fractures of medial wall may involve what?
- Fractures in inferior wall may involve what?
*
A
- Fractures of medial wall may involve ethmoidal and sphenoidal sinuses
- Fractures in inferior wall may involve maxillary sinus; may entrap the inferior rectus muscle, limiting upward gaze
21
Q
Superior wall of orbit is stronger but what can happen?
A
Superior wall is stronger but thin enough to be penetrated
– a sharp object may pass into frontal lobe of brain.
22
Q
Orbital fractures often result in what?
A
in intra-orbital bleeding, which exerts pressure on the eyeball, causing exophthalmos (protrusion of the eyeball). D/t increase pressure
23
Q
List the sinuses
A
24
Q
label them
A
25
25
What is the purpose of the TMJ?
Open and close mouth
26
What makes up the TMJ and gives the joint strength
* Fibrous capsule and lateral ligament
* Sphenomandibular and stylomandibular ligaments also support the jaw
27
What is made up of the lateral pterygoid?
superior and inferior head
28
How can one dislocate TMJ?
Yawning or taking a large bite
* excessive contraction of **lateral pterygoids**
* heads of mandibles to **dislocate anteriorly**
* mandible remains depressed and the person may not be able to close the mouth.
Sideways blow to the chin when the mouth is open
* dislocates the TMJ on the side that received the blow.
* traumatic dislocation and **rupture of the joint capsule and lateral ligament** can injury
to auriculotemporal nerve supplying the TMJ
* leads to laxity and instability of the TMJ.
28
What are the layers of the scalp?
* Skin
* CT (dense)
* Aponeurosis
* Loose CT
* Pericranium
29
What is a danger area of the layers of the scalp?
Loose connective layer
* Danger area - pus or blood spreads easily through emissary veins/calvaria (deep down into dipole veins then dura matter-> dura venous sinus)
* can reach intracranial structures e.g. meninges
29
Where can infection not pass in scalp injuries?
* **into the neck** (occipital belly of the occipitofrontalis muscle attaches to the occipital bone and mastoid parts of the temporal bones)
* **laterally** beyond the zygomatic arches (epicranial aponeurosis continuous with the temporal fascia that attaches to these arches)
30
Where can infection go to in scalp injuries?
* **enter eyelids and root of nose** (frontal belly of the occipitofrontalis muscle inserts into the skin and subcutaneous tissue, not bone)
* **ecchymoses** (purple patches) develop as a result of blood in subcutaneous tissue and skin of eyelids and surrounding regions.
* “black eyes” can result from injury to scalp or forehead.
31
List out the meninges (+ sublayers)
32
What is the flooe of the cranium (base)
cavernous sinus
33
How do the sinuses flow and where is common point where they all meet?
34
arachnoid granulation goes into what?
Superior sagittal sinus (venous blood) so CSF can be reabsorbed
35
* Basilar and occipital sinuses communicate through what?
* Because these venous channels are valveless, what can be an issue?
* Thus, pus in abscesses and tumor cells in these regions may what?
* Basilar and occipital sinuses communicate through foramen magnum via internal vertebral venous plexuses
* Because these venous channels are valveless, compression of the thorax, abdomen, or pelvis (e.g. heavy coughing and straining) may force venous blood into dural venous sinuses.
* Thus, pus in abscesses and tumor cells in these regions may **metastasize** to the vertebrae and brain.
36
What allows the spreading of infection from inferior to superior head?
Internal vertebral venous-plexus since they are valveless
37
where are the dural venous sinuses? (AND LABEL)
Dural venous sinuses of internal surface of cranial base
38
What is the membrane that is inferior below cerebrum?
tentorium cerebelli
39
Why is the cavernous sinus important?
40
Fracture of Cranial Base (Basilar):
* What artery may be torn and what might happen?
* What is the result of this situation?
* **Internal carotid artery** may be torn,producing an arteriovenous fistula within the cavernous sinus.
* Arterial blood rushes into the cavernous sinus, enlarging it and forcing **retrograde blood** into its venous tributaries, especially the ophthalmic veins.
* As a result,eyeball protrudes (**exophthalmos**) and conjunctiva becomes engorged (**chemosis**).
41
The protruding eyeball pulsates in synchrony with the radial pulse, a phenomenon known as what?
pulsating exophthalmos.
42
What also might be affected when fracturing the cranial base?
Because CNs III,IV,V1,V2 ,and VI lie in or close to the lateral wall of the cavernous sinus, they may also be affected when the sinus is injured
43
What else can happen instead when a blow to the head happens and the cranial base is not fractured?
Blow to head can detach the periosteal layer of dura from the calvaria without fracturing the cranial bones -> Dural layers deattach
44
However, in the cranial base, the two dural layers are firmly attached and difficult to separate from the bones. Consequently, a fracture of the cranial base usually does what?
a fracture of the cranial base usually tears the dura and results in leakage of CSF
45
Label
46
Label
47
What is the ventricular system of the brain?
48
* What is hydrocephalus?
* What happens if there is an excess of CSF?
* Overproduction of CSF, obstruction of its flow, or interference with its absorption results in an **excess of CSF in the ventricles**
* Excess CSF **dilates the ventricles**; thinning the surrounding brain; and, in infants, **separates the bones** of the calvaria because the sutures and fontanelles are still open
* When it occurs in infants and young children, **the head enlarges**
49
* In severe cases and untreated hydrocephalus, what may happen?
* Can hydrocephalus occur in adults?
* In severe cases, untreated hydrocephalus may result in nerve damage, vision loss and even death.
* Can also occur in adults, without macrocephaly symptom.
50
Epidural hematoma:
* What is the origin?
* Torn branches of what?
* What is the result ?
* What does it look like under x ray?
- arterial in origin
- torn branches of middle meningeal artery
- brain compressed as blood mass increases
51
Subdural hematoma:
* What is the origin? Results in what?
* What can happens with the leaked blood?
* May develop when?
* What does it look like under x-ray?
* **typically venous** in origin and commonly results from **tearing of a superior cerebral vein** bridging in as it enters the superior sagittal sinus.
* escaped blood splits open dural border cell layer, **creates a space at the dura–arachnoid junction**
* usually follows a blow to the head that jerks and injures brain inside cranium
* hematoma may develop over **many weeks** from venous bleeding.
52
Subarachnoid hemorrhage:
* What is the origin?
* Results from what?
* Some associated with what?
* What does it look like under x ray?
* extravasation of blood, usually **arterial**, into subarachnoid space
* often result from **rupture of a saccular aneurysm** (sac-like dilation on an artery).
* some associated with head trauma involving cranial fractures and cerebral lacerations, or meningeal irritation
53
Actions of:
* Orbiculatis oculi:
* Levator labii superioris:
* Zygomaticus major and minor:
* Risorius:
* Orbiculatis oculi: Close eye
* Levator labii superioris: lip elevator
* Zygomaticus major and minor: lip elevator
* Risorius: lip elevator
54
Actions of:
* Temporalis:
* Masseter:
* Lateral pterygoid:
* Medial pterygoid:
* Temporalis: Elevator of mouth
* Masseter: Elevator of mouth
* Lateral pterygoid: opens mouth and moves lateral
* Medial pterygoid: closes mouth
55
56
57
What are the number of different sets of vertebrae and what is their structure?
58
* What is between each vertebrae?
* What is between L5 and sacrum?
* Intervertebral disc
* Lumbosacral angle
59
Excessive thoracic kyphosis:
* What is it ?
* What can it result from?
* What is the result?
* What is shown in older women with osteoporosis?
- **abnormal increase** in the **thoracic curvature**
- can result from **erosion** of anterior part of one or more vertebrae.
- progressive erosion and collapse of vertebrae results in an overall loss of height.
- **widows hump** colloquial kyphosis in older women from osteoporosis
- however, occurs in geriatric people of both sexes
60
Excessive lumbar lordosis:
* What is it?
* Associated with what?
* Population affected?
- **abnormal increase** in the **lumbar curvature**
- associated with weakened trunk musculature, especially of the anterolateral abdominal wall.
- women develop a temporary lordosis during late pregnancy.
61
Scoliosis:
* What is it?
* How is the spinous processes?
* Common in who?
* Causes what?
- abnormal lateral curvature accompanied by rotation of the vertebrae
- spinous processes turn toward the cavity of the abnormal curvature.
- common deformity of the vertebral column in pubertal girls
- causes include asymmetric weakness of the intrinsic back muscles (myopathic scoliosis), failure of half of a vertebra to develop (hemivertebra), and a difference in the length of the lower limbs are causes of scoliosis
62
What is the structures of vertebra?
63
Spinal stenosis:
* May be caused by what?
* Lumbar spinal nerves do what?
* May be a hereditary anomaly that can make a person more vulnerable to age-related degenerative changes, such as **IV disc protrusion**, further compromising the size of the vertebral canal
* Also note that **lumbar spinal nerves increase in size as the vertebral column descends, but the IV foramina decrease in size**
63
Spinal Stenosis:
* What is it?
* May cause what?
* Txt?
* Stenotic(narrow) vertebral foramen in one or more lumbar vertebrae
* May cause **compression** of one or more **spinal nerve roots** occupying the vertebral canal.
* Surgical treatment may consist of **decompressive laminectomy**-> remove lamina for more space
64
Laminectomy:
* What is it?
* Term also commonly used to denote what?
* Provides what?
* Surgical **excision** of one or more **spinous** processes and their supporting **laminae** (#1)
* Term also commonly used to denote **removal** of most of the **vertebral** **arch** by transecting the **pedicles** (pediculectomy) (#2)
* Provides **access to vertebral canal** to relieve pressure on spinal cord or nerve roots, commonly caused by a tumor, herniated IV disc, spinal stenosis, or bony hypertrophy
65
C1 connects with what?
Occipital condyle sits in the superior art. factet of C1
66
What structure is only present in the cervical vertebrae?
Foramen transverarium which allows the vertebral artery to travel up to the circle of willis
67
What happens when the transverse ligament rupture? Complete dislocation?
* When the transverse ligament of the atlas **ruptures**, the **dens is set free**, resulting in atlanto-axial subluxation or **incomplete dislocation** of the median atlanto- axial joint.
* When **complete dislocation** occurs, the **dens may be driven into the upper cervical region of the spinal cord**, causing quadriplegia, or into the medulla of the brainstem, causing **dealth**
68
What happens when there is a fracture of the atlas?
* Vertical forces (e.g. striking bottom of pool in diving accident) compresses the lateral masses between the occipital condyles and the axis drive them apart, fracturing one or both of the anterior or posterior arches
* If the force is sufficient, rupture of the transverse ligament that links them will also occur
69
* The resulting Jefferson or burst fracture in itself does not necessarily result in what?
* What is more likely in this case?
* The resulting Jefferson or burst fracture in itself does not necessarily result in spinal cord injury because the dimensions of the bony ring actually increase.
* Spinal cord injury is more likely, however, if the transverse ligament has also been ruptured
70
Thoracic vertebrae (T1–T12) form the posterior part of the skeleton of the thorax and articulate with what? How?
With the ribs via the transverse costal facet (for tubercle of rib) and superior+inferior costal facels (for head of rib)
71
Vertebral body osteoporosis:
* Common what?
* Results from what?
* Affects what?
* What happens to the bones?
* Common **metabolic bone disease**
* Results from a net **demineralization** of the bones caused by a disruption of the normal balance of calcium deposition and resorption (covered in physiology).
* Affects the entire skeleton but **most affected areas are the neck of the femur, the bodies of vertebrae, the metacarpals and the radius.**
* These bones become **weakened and brittle** and are subject to **fracture**.
72
Vertebral body osteoporosis:
* What is demineralization?
* What does it especially affect?
* What do later stages show?
* **Demineralization** - diminished radiodensity of the trabecular (spongy) bone of the vertebral bodies, causing the thinned cortical bone to appear relatively prominent (Fig. B2.7A,B).
* Especially **affects trabecular bone** of the vertebral body (see Fig. B2.9A). Loss of the horizontal supporting trabeculae results in thickening of the vertical struts (Fig. B2.7A).
* Later stages x-rays reveal **vertebral collapse**
(compression fractures) and increased **thoracic kyphosis**
73
Ankylosing spndylitis:
* What is it?
* Over time causes what?
* If ribs are affected, what can happen?
* What is it called when found on and off x-ray?
- **Inflammatory disease**
- Over time can cause **vertebrae to fuse**, makes the spine less flexible and can result in a hunched posture.
- If ribs are affected, it can be difficult to breathe deeply.
- When condition is found on **X-ray, it is called ankylosing spondylitis**
- When condition **can't be seen on X-ray** but is found based on symptoms, blood tests and other imaging tests, it is called **nonradiographic axial spondyloarthritis.**
74
Ankylosing spondylitis:
* When are symptoms typically happening?
* Txt?
- Symptoms typically begin in early adulthood.
- There is no cure for ankylosing spondylitis, but treatments can lessen symptoms and possibly slow progression of the disease.
75
What is the landmark of lumar vertebrae?
Sacral promontory: where L5 meets sacrum
76
Spina bifida occulta:
* Common or uncommon?
* What happens?
* Present in what? How?
* Most people dont have what?
* Most common congenital anomaly of the vertebral column
* Laminae (embryonic neural arches) of L5 and/or S1 **fail to develop normally and fuse.**
* Present in up to 24% of people, is **concealed by skin**, but its location is often indicated by a **tuft of hair**.
* Most people with spina bifida occulta have **no back problems**
77
Spina bifida cystica:
* What happened?
* What are the different types?
* What is usually present?
* One or more **vertebral arches may almost completely fail to develop**
* Herniation of the meninges (**meningocele**) and/or the spinal cord (**meningomyelocele**).
* Usually, **neurological symptoms** are present in severe cases of meningomyelocele (e.g. paralysis of limbs and disturbances in bladder and bowel control).
78
What is spondylolysis and spndylolisthesis?
79
80
Sacral vertebral:
* What is basiclaly the spinous process?
* What is the posterior sacral foramina?
* What is the sacral hiatus?
* Median crest
* Holes for nerve endings to travel through
* inferior aspect to allow us to access epidural space
81
What is the vertebra prominens?
82
What comes together to form the dimples on back?
Posterior superior iliac spine and spine
83
84
* In the intervertebral disc, what is composed of?
* What is on the front and back of it? why?
84
Herniation of nucleus pulposus:
* Casues what?
* If degeneration of the posterior longitudinal ligament and wearing of the anulus fibrosus has occurred, what may happen?
* Herniations usually occur how?
* Herniation or protrusion of the gelatinous nucleus pulposus into or through the anulus fibrosus is a well-recognized cause of **low back and lower limb pain.**
* If degeneration of the **posterior longitudinal ligament** and wearing of the anulus fibrosus has occurred, the nucleus pulposus may herniate into the vertebral canal and **compress the spinal cord or nerve roots of spinal nerves** in the cauda equina (Fig. B2.8).
* Herniations usually occur **posterolaterally**,where the anulus is relatively thin and does not receive support from the posterior or anterior longitudinal ligaments.
85
Herniation of nucleus pulposus:
* Posterolateral herniation is most common where?
* Chronic pain resulting from what?
* Sciatica?
* Posterolateral herniation is most common in the lumbar region; approximately 95% of protrusions occur at the L4–L5 or L5–S1 levels.
* Chronic pain resulting from the spinal nerve roots being compressed by the herniated disc is referred to the area (**dermatome**) supplied by that nerve.
* **Sciatica**, pain in the lower back and hip and radiating down the back of the thigh into the leg, is often caused by a **herniated lumbar IV disc or osteophytes** that compress the L5 or S1 component of the sciatic nerve.
86
What is the venous drainage of vertebral column?
* Ant. external vertebral venous plexus in vertebral body
* Post. external vertbral venous plexus in intervert. space
87
# Relationship of vertebral column, spinal cord, and spinal nerves.
* Which has the epidural space in spinal cord?
* Where does the SC end?
* What is the cauda epuina?
88
Where does more or less gray matter present in the SC?
89
* Where is the spinal nerve located?
* What is teh epidural space occupied by?
90
Spinal cord in situ: vasculature and meninges with associated spaces?
Most proximal spinal nerves and roots are accompanied by radicular arteries, which do not reach the posterior, anterior, or spinal arteries. Segmental medullary arteries occur irregularly in the place of radicular arteries—they are really just larger vessels that make it all the way to the spinal arteries.
91
What are the major blood supplies of the spinal cord?
92
Lumbar puncture & epidural anesthesia:
* To obtain a sample of CSF from the lumbar cistern: what might happen?
* What is a lumbar spinal puncture?
* Flexion of the vertebral column facilitates insertion of the needle by what?
* Under aseptic conditions, the needle is inserted where?
* To obtain a **sample of CSF** from the lumbar cistern, a lumbar puncture needle, fitted with a stylet, is inserted into the **subarachnoid space.**
* **Lumbar spinal puncture (spinal tap)** is performed with the patient leaning forward or lying on the side with the **back flexed.**
* Flexion of the vertebral column facilitates insertion of the needle by **spreading the laminae and spinous processes apart, stretching the ligament flava**
* Under aseptic conditions, the needle is inserted in the midline between the spinous processes of the **L3 and L4 (or the L4 and L5) vertebrae.**
* At these levels in adults, there is reduced danger of damaging the spinal cord
| first pop: ligamentum flavum, second pop is epidural space
93
Epidural Anesthesia (Blocks):
* An anesthetic agent can be injected into where?
* he anesthetic has a direct effect on what?
* The patient loses what?
* An anesthetic agent can also be injected into where?
* The distance the agent ascends (and hence the number of nerves affected) depends on what?
94
What are superficial extrinsic back muscles+actions
1. Trapezius-> Levator, depressor
2. Latissimus Dorsi -> thorco-lumbar facia to arm
3. Levator Scapulae-> at the medial boarder of scapula to cervical vertebrae
4. Rhomboids-> retracts
95
Triangle of Auscultation?
Btw Latissimus dorsi, trapezium and Rhomboids Major
96
What is the Intermediate extrinsic back muscles+action
* Serratus Posterior (superior and Inferior)
* helps to elevate the upper ribs during inhalation
97
What are the superficial layer of intrinsic back muscles?
Splenius muscles:
1. Splenius Cervicis
2. Splenius Capitis
97
What are the intermediate layer of intrinsic back muscles?
Erector spinae muscles:
1. Iliocostalis
2. Longissimus
3. Spinalis thoracis
| Which retracts
98
What is the deep layer of the intrinsic back muscles.
Semispinalis, Multifidus, Rotatores.
