Anatomical terms and the orbit

Question 1

What are the three anatomical planes

Answer 1

Sagittal plane
- divides the body into left and right halves

Cornal (fronal) plane
- divides the body into front and back halves

Transverse (horizontal) plane
- divides the body into upper and lower halves

Question 2

Name the anatomical positions for front and back respectively

Answer 2

Anterior

Posterior

Question 3

Name the anatomical positions for above and below

Answer 3

Superior

Inferior

Question 4

Name the anatomica posistions for towards the temples and towards the nose

Answer 4

Temporal

Nasal

Question 5

What does inter-(structure) mean

Answer 5

between

Question 6

What does intra- (structure) mean

Answer 6

within

Question 7

What does para-(structure) mean

Answer 7

Adjacent, immediately next o

Question 7

What does peri- (structure) mean

Answer 7

Around/ About

Question 8

What is the orbit

Answer 8

Bony cavity of skull which surrounds and protects the eye and its appendages

Question 9

What are the seven bones of the orbit

Answer 9

Frontal
Zygomatic
Maxillary
Ethmoid
Sphenoid (greater and lesser wing)
Lacrimal
Palatine

Question 10

What are the four orbital wall

Answer 10

Roof
Floor
Medial
Lateral

Question 11

What bones make the roof of the orbital wall

Answer 11

Frontal and lesser wing sphenoid

Question 12

What bone makes the lateral side of the orbital wall

Answer 12

Greater wing of spehnoid

Zygomatic

Question 13

What bone makes the floor of the orbital wall

Answer 13

Maxillary

Zygomatic

Small contribution from palatine

Question 14

What bone makes the medial side of the orbital wall

Answer 14

Ethmoid

Lacrimal

Lesser wing of sphenoid

Maxillary

Question 15

What is a foramen

Answer 15

An opening or orfice that transmits blood vessels, nerves and muscles to connect one part of the body to another

Question 15

what is a fissure

Answer 15

A groove, natural divsion, gap, or space which is caused by the incomplete union of two bones

Question 15

What is a fossa

Answer 15

A deperessed area that houses a structure

Question 16

What is a notch

Answer 16

Indentation at the edge of the bone

Question 16

What anatomical landmark(s) are present on the roof of the orbit

Answer 16

Supraorbital notch (formane)
- has supraorbital foramen, opening to transmit supraorbital nerves and vessels from the orbit onto the surface of the frontal bone

Lacrimal gland fossa
- houses lacrimal gland

Trochlear fossa
- point of attachment for the superior oblique muscle

Question 16

What anatomical landmark(s) are present in the medial wall

Answer 16

Lacrimal fossa
- houses the lacrimal sac

Question 17

What anatomical landmark(s) are present in the floor

Answer 17

Infraorbital foramen
- Transmits infraorbital nerve and vessels

Question 18

What anatomical landmark(s) are presesnt in the apex

Answer 18

Superior orbital fissure
- gap between lesser and greater wings of spehnoid
- has a common tendinous ring of 4 recti muslce (superior, medial, lateral, inferior rectus)
- transmits lacrimal, frontal, trochlear nerve and superior opthalmic vein

Inferior orbital fissure
- gap between greater wing sphenoid and maxillary bone
- transmits maxillary, zygotamic nerve, branches of pterygopalatine ganglion and inferior opthalmic vein

Optic foramen (canal)
- Opening in lesser wing spehnoid, medial to superior orbital fissure
- transmits optic nerve and artery

Question 19

What is the orbital fascia

Answer 19

connective tissue that envelops all the orbital contents

Associated with adipocytes and fats

Question 20

What is the function of the orbital fascia

Answer 20

To support and insulate orbital soft tissue structures To assist with free, unimpeded movement of the eyeball

Question 21

What strutures does the orbital fascia comprise of

Answer 21

periorbita, orbital septum, Tenon's capsule, mucle sheath, suspensory ligaments and check ligaments

Question 22

What is the periorbita

Answer 22

A conically shaped fibrous membrane that lines the orbital cavity, foramens, fissures and encloses the eyeball

Question 23

What is the function of the orbital septum

Answer 23

Membrane that separates the eyelids from the orbital contents so as to prevent the spread of haemorrhage and infection

Question 24

Give a description of the orbital septum

Answer 24

Perforated by blood vessels, nerves and the aponeurosis of the levator muscle Is relatively week, may perforate, allowing prolapse of orbital fat or lacrimal gland

Question 25

What is the tenon's capsule (bulbar fascia/ bulbar sheath)

Answer 25

External sheath enveloping sclera, seperated from the sclera (tenon's space)

Question 26

What is the function of the muscle sheaths

Answer 26

Provide support for the nerve fibres and vessels

Question 27

What is the function of the muscle check ligments

Answer 27

Expansion of muscle sheaths, which probably restrains the activity of the muscle

Question 28

What is the function of suspensory ligaments

Answer 28

Support and prevent eyeball from dropping if orbital floor is damaged or removed

Question 29

What is the ocular media

Answer 29

A set of transparent eye structures, through which light passes before it reaches the retina.

Question 30

What does the ocular media consist of

Answer 30

PCTF Cornea Aqueous humour Crystalline lens Viterous humour