Term
| What type of bones are formed in cartilage and then ossified? |
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Definition
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Term
| What type of embryological cells form the bony orbit? |
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Definition
| Mesenchyme surrounding the optic vesicle[image] |
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Term
| In what type of bone formation are bones ossified from connective tissue? |
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Definition
|
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Term
| From what cells is the orbital wall derived from? |
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Definition
| Cranial neural crest cells |
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Term
| What two processes fuse together to form the medial, inferior, and lateral orbital walls? |
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Definition
| The lateral nasal process and the maxillary process. |
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Term
| What are the functions of the eyelid? |
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Definition
Protect
Lubricate
Maintain the ocular surface |
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Term
| What forms the orbital roof? |
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Definition
| The capsule of the forebrain |
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Term
| What is the first bone to develop and when? |
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Definition
| The maxillary bone at 6 weeks gestation |
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Term
| Does the maxillary bone form from endochondral or mebranous ossification? |
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Definition
| Membranous, bones are ossified from connective tissue. |
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Term
| Where do secondary ossification centers of the maxillary bone develop? |
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Definition
| The adjacent orbitonasal and premaxillary region. |
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Term
| Through what process does the sphenoid bone develop? |
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Definition
| Endochondral and intramembranous ossification |
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Term
| When do the lesser wing of the sphenoid and the optic canal begin as cartilaginous structures? |
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Definition
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Term
| When does the greater wing of the sphenoid bone begin to ossify after being preformed in cartilage? |
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Definition
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Term
| When does the optic strut ossify? |
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Definition
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Term
| What bone separates the optic canal from the superior orbital fissure? |
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Definition
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Term
| When do the greater and lesser wings of sphenoid join together? |
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Definition
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Term
| What is the only part of the orbital wall that is not completely ossified at birth? |
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Definition
|
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Term
| What bones make up the orbit? |
|
Definition
Sphenoid
Frontal
Ethmoid
Maxillary
Zygomatic
Palatine
Lacrimal |
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Term
| What is the strongest portion of the orbital rim? |
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Definition
|
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Term
| What two bones make up the lateral orbital rim? |
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Definition
| The zygomatic bone and the zygomatic process of the frontal bone. |
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Term
| What three structures connect to the tubercle of the zygomatic bone? |
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Definition
1. The lateral canthal ligament
2. The lateral rectus muscle check ligament
3. The aponeurosis of the levator palpaebrae superioris muscle |
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Term
| What is the depression in the floor of the orbit? |
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Definition
| A fossa for the origin of the inferior oblique muscle. |
|
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Term
| From what structure does the orbital floor separate the eye? |
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Definition
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Term
| What provides support for the orbital floor? |
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Definition
| The maxillary ethmoid buttress and the infraorbital sulcus/canal |
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|
Term
| Which wall of the orbit is the most easily deformed? |
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Definition
|
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Term
| What is the lamina papyracea/ |
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Definition
| The lateral surface of the labyrinth of the ethmoid bone is formed of a thin, smooth, oblong plate, the lamina papyracea (or orbital lamina), which covers in the middle and posterior ethmoidal cells and forms a large part of the medial wall of the orbit. |
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|
Term
| What provides support for the orbital floor? |
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Definition
| The maxillary ethmoid buttress and the infraorbitalsulcus/canal. |
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|
Term
| What are the fracture points of a tripod fracture? |
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Definition
The zygomaticomaxillary suture
The frontozygomatic suture
The zygomatic arch |
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Term
| When a tripod fracture occurs, which way does the complex rotate upon contraction of the muscle across the fracture? |
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Definition
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Term
| Why can't a patient with a tripod fracture open his mouth? |
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Definition
| Because the coronoid process of the mandible contracts the rotated zygomatic arch. |
|
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Term
| What are three patient symptoms of a tripod fracture? |
|
Definition
1. He can't open his mouth.
2. The cheek looks depressed.
3. muscle spasm |
|
|
Term
|
Definition
| Buphthalmos is a congenital condition of the eye. An abnormally narrow angle between the cornea and iris blocks the outflow of aqueous humor, which leads to an increased intraocular pressure and a characteristic bulging enlargement of the eyeball. Other clinical signs include excessive tearing and cupping of the optic disk, which may the first sign to develop. |
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Term
| How much difference between the eyes as measured in exopthalmometry is significant? |
|
Definition
| A difference of two or more. |
|
|
Term
| What is the principle elevator of the eyebrow? |
|
Definition
|
|
Term
| What three muscles depress the eyebrow? |
|
Definition
1. Corrugator supercili
2. Procerus
3. Orbicularis |
|
|
Term
| What does the superior eyelid develop from? |
|
Definition
| A mesenchymal condensation located above the optic cup called the frontonasal (paranasal) process. |
|
|
Term
| What does the inferior eyelid develop from? |
|
Definition
| A mesenchymal condensation located below the optic cup called maxillary (visceral) process. |
|
|
Term
| Where does the superior lid margin rest in adults? |
|
Definition
| 2 mm below the superior canthus |
|
|
Term
| Where does the inferior lid margin rest in adults? |
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Definition
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|
Term
| What makes up the anterior lamellae of the eyelid? |
|
Definition
| skin, pretarsal orbicularis oculi, gland of Zeiss and gland of Moll |
|
|
Term
| What makes up the posterior lamella? |
|
Definition
| tarsal plate, conjunctiva, associated glands |
|
|
Term
| What type of glands are the Glands of Zeiss? |
|
Definition
| modified sebaceous glands |
|
|
Term
| What types of glands are the glands of Moll? |
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Definition
| eccrine or modified sweat glands that secrete their contents along the follicle shaft p. 161 Remington |
|
|
Term
| What is the muscle of Riolan and where is it located? |
|
Definition
It runs horizontally between the pretarsal orbicularis muscle and the tarsal plate in the upper and lower eyelid
Remington p. 158 |
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Term
| What is the present day function of the human crstyalline lens? |
|
Definition
1. UV filter
2. accomodates to focus light on retina |
|
|
Term
| What is the light absorbing part of pigment (chromophore)? |
|
Definition
|
|
Term
| What protein is the chromophore coupled to? |
|
Definition
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