Handout on parietal bone : brief and easy description

Parietal bone

1.       Anatomical points:

·   Superior border is longest, thickest and serrated,

·   Superior border  lies in median plane

·    ** Anterior  inferior angle is acute and internally marked by groove for anterior  division of middle meningeal vessel 

2.       Morphological type : Flat bone

3.       Structure of bone : inner and outer table(compact bone )  and middle diploe (spongy bone)

4.       Ossification : intra membranous ossification

5.       Development : neural crest

6.       Parts:  identify

·         four borders:

a)       superior border : longest, thickest and serrated and internally marked by a sulcus known as sagittal sulcus which lodges superior sagittal sinus , Granular pit present side of sagittal sulcus which lodge arachnoid granulation

b)      inferior border irregular and serrated and internally marked by posterior division of middle meningeal artery (at the middle of inferior border )

c)       anterior and posterior border are straight and serrated

·         superior border is articulated with opposite parietal bone formed sagittal suture

·         Anterior border is articulated with frontal bone formed coranal suture

·         Posterior border is articulated with occipital bone formed lambdoid  suture

·         Inferior border is articulated with

a)      Greater wing of sphenoid bone

b)       Squamous part of temporal bone

c)        Petrous part of temporal bone .

·         What is pterion ?

·         Ans : union between four bones

a)      Frontal bone

b)      Anterior inferior angle of parietal bone

c)       Greater wing of sphenoid

d)      Squamous part of temporal bone  

e)      What is the importance of pterion ?

f)       Internal surface of pterion is lodged by anterior division of middle meningeal artery 

·         Four angles :

a)      Anterior superior angle forms bregma

b)      Posterior superior angle forms Lambda ( in children it is called pesterior frontanelle )

c)       Anterior inferior angle forms pterion and internally marked by groove for anterior division of middle meningeal artery

d)      Posterior inferior angle forms asterion and internally a groove present which lodges sigmoid sinus

External Surface of parietal bone :

·         parietal tuberosity : maximum transverse diameter of skull measures by these points

·         Superior and inferior temporal line

Internal surfaces of parietal bone :

·         impression of sulci and gyri of cerebrum

·         impression of anterior division of middle meningeal artery at internal surface of anterior inferior angle

·         impression of posterior division of middle meningeal artery at middle of inferior border

·         sagittal sulcus near the superior border

·         sulcus for sigmoid sinus near the posterior inferior angle

7.       Identify the groove for middle meningeal vessels: identify, origin of middle meningeal vessels,

8.       Through which opening, middle meningeal vessel is enter into cranial cavity? 

Ans: Foramen spinosum

Frontal bone : short questions with answer (short review)

Frontal bone

1.       Anatomical points:

·   Squamous part of frontal bone lies vertically

·   Orbital plates are directed downward and horizontally

·   Nasal spine is directed downward and forward

2.       Morphological type: pneumatic flat bone   

3.       Structure of bone : Frontal bone is formed by inner and outer table (compact bone) and middle diploe (sgongy bone)

4.       Ossification : intramembranous ossification (it is ossify from membrane )

5.       Development : Neural crest ( derived from ectoderm)

6.       Parts:  Identify

·         Squamous part:

-          External surface of squamous part : Frontal tuberosity / supercilliary arch / supraorbital margin/ superobital notch or foramen / glabella

-          Internal surface of squamous part : impression for cerebral sulci and gyri / sagittal sulcus or groove for superior sagittal sinus / frontal crest / foramen caecum

·         Orbital part                                                                                                                                              

·         Zygomatic processes

·         Nasal notch : name of the bones articulate with nasal notch

·         Right side (from medial to lateral ) right nasal bone,  right frontal process of maxilla and right lacrimal bone

·         Left side (from medial to lateral ) left nasal bone,  left frontal process of maxilla and left lacrimal bone                                                                                                                                             

·         Ethmoidal notch:  name of the bone articulate with ethmoidal notch?

·          Ethmoid notch is situated in between two orbital plates and articulated by cibriform plate of ethmoid

1.       What is metopic suture?

Ans: developmentally frontal bone is derived from two segment , later join in mid line . in 9% cases a suture may persist at median plane and inferiorly . It is sometime associated with frontal sinus agenesis and hypoplasia

2.        coronal suture: which bones forms this suture

Ans : in front frontal bone behind right and left parietal bone

3.       Foramen related to this bone and structure passing through it

Ans: foramen caecum : transmit an emissary vein from nasal mucosa to superior sagittal sinus

Supra orbital foramen or notch : transmits supra orbital nerve and vessel

4.       Show lacrimal fossa, what structure lodge within it:

 Ans : lacrimal gland

5.       Nerve supply of lacrimal gland

Ans: lacrimal nerve

Systemic embryology : Skeletal system: MCQs on the basis of langman’s medical embryology book

Systemic embryology :

Skeletal system on the basis of langman’s medical embryology book

Mcqs

Questions

1.      Skeletal system develops from

a)     Paraaxial mesoderm ,Surface ectoderm ,Endoderm

b)    Paraaxial mesoderm, Neural crest, Lateral plate mesoderm

c)      Neural crest ,Surface ectoderm ,Endoderm

d)     Paraaxial mesoderm ,Surface ectoderm , intermediated mesoderm

e)     e) Paraaxial mesoderm , neuroectoderm ,Endoderm

2.  Mesenchyme mean

a) fetal connective tissue

 b) mesenchyme have capacity to formed muscle

 c) mesenchyme always originate from mesoderm

d) mesenchyme of head and neck region originate from surface ectoderm

e) mesenchyme is devoid of cells

3. vertebral column and ribs develops from

a) somites

 b) lateral plate mesoderm

 c) neural crest

d) intermediate mesoderm

 e) endoderm

4. Bone and connective tissue and muscles of limb develops from

a) endoderm , ectoderm

b) neural crest and endoderm

 c) lateral plate mesoderm and somites

d) neural crest and somites

e) lateral plate mesoderm and neural crest

5) ossification center develops in a cartilaginous model means : membranous ossification / endochondral ossification

6. AER --controls anterioposterior patterning of limb/ regulates limb outgrowth/ rotation of limb

7. Amelia means-- partially formed limb / absence of limb/ deformed limb

8. polydactyly means-- fused finger/ small sized finger/ extra finger

9. Congenital hip dislocation common in female / male

10. Occipital somites and somitomere  contritubes to formation of cranial vault and base of the skull: true / false 

Answers:

2.     Skeletal system develops from

a)     Paraaxial mesoderm ,Surface ectoderm ,Endoderm

b)    Paraaxial mesoderm, Neural crest, Lateral plate mesoderm

c)      Neural crest ,Surface ectoderm ,Endoderm

d)     Paraaxial mesoderm ,Surface ectoderm , intermediated mesoderm

e)     e) Paraaxial mesoderm , neuroectoderm ,Endoderm

2.  Mesenchyme mean

a) fetal connective tissue

 b) mesenchyme have capacity to formed muscle

 c) mesenchyme always originate from mesoderm

d) mesenchyme of head and neck region originate from surface ectoderm

e) mesenchyme is devoid of cells

3. vertebral column and ribs develops from

a) somites

 b) lateral plate mesoderm

 c) neural crest

d) intermediate mesoderm

 e) endoderm

4. Bone and connective tissue and muscles of limb develops from

a) endoderm , ectoderm

b) neural crest and endoderm

 c) lateral plate mesoderm and somites

d) neural crest and somites

e) lateral plate mesoderm and neural crest

5) ossification center develops in a cartilaginous model means : membranous ossification / endochondral ossification

6. AER --controls anterioposterior patterning of limb/ regulates limb outgrowth/ rotation of limb

7. Amelia means-- partially formed limb / absence of limb/ deformed limb

8. polydactyly means-- fused finger/ small sized finger/ extra finger

9. Congenital hip dislocation common in female / male

10. Occipital somites and somitomere  contritubes to formation of cranial vault and base of the skull: true / false  

Easy tips for microscope handling

How to use a compound microscope

Know your microscope : know the all part of microscope and their use. Repeat these things until you become familiar.

Move the microscope carefully:

1.     use your both hand , one arm place at arm of microscope and another hand place base of microscope .

2.     hold the microscope close to your body as far as possible.

3.     Put the microscope away from the edge of table

How to focus a histological slide without breaking

1.     Put the slide on the stage and secure by stage clips

2.     At 1^st you use low power lens ×4, just for scanning the slide

3.     Lower the condenser lens

4.     Turn on the light (Illuminator)

5.     Observe where the tissue present in the slide

6.     By moving stage adjustment node you place the tissue at the centre of light seeing from outside ( not adjust this things by placing your eye at optical lens , it kill your time)

7.     Now from outside your lower the objective lens, then place your eye at optical lens and move the objective lens upward

8.     Never lower the objective lens when your eyes are at the optical lens . if you follow this rules you never able to break a slide

Tips for better focusing :

1.     When you use ×4 objective lens , condenser lens should at lower most position and diaphragm should widely open

2.     When you use ×10 objective lens, you move the condenser lens upward and diaphragm should close little bit

3.     When you use ×40 objective lens, you move the condenser lens upward and diaphragm should close little bit

4.     When  you use ×100 objective lens, give oil on the slide and lower the objective lens until it touch the slide , you move the condenser lens upward until it touch the slide and diaphragm should close little more

5.     Before observing the slide one should use the fine adjustment knob , because vision varies person to person

Tips for easy handling of microscope when you observing slide by placing your eye on optical lens

1.     Sit down

2.     After focusing the slide place one hand on fine adjustment knob and another hand on the stage adjustment knob ,

3.     Only these two location you need to handle for  observing  the slide

4.     If you needed to focus the slide again or needed to lower the objective lens you should not place your eye at optical lens at that time , you must see outside and observe until the objective lens touch the slide , than place the eyes on optical lens and move objective lens upward

5.     If the microscope is binocular then adjust the eye pieces according to the distance of your both eye , if the microscope is uniocular then one eye place to eye piece and another one keep open ( don’t close one eye)

Tips for using stage adjustment knob:

                      In microscope you using multiple lens , so you should remember following rules before moving

                       the slide

1.     If you want to move the slide upward you must move the slide downward

2.     If you want to move the slide right you must move the knob to the left and vice versa  

Maintain your microscope :

1. After use turn off the light
2. Remove the slide
3. Change the objective lens to lower power
4. Lower the condenser lens
5. Don’t touch the lens
6. Clean lens by lens paper or lilen cloth
7. Cover the microscope
8. Place the microscope in a dust free location
9. Use silicon in the box of microscope for lowering moistures