بسم الله الرحمن الرحيم
Before we start I want to mention that this lab is a review of what we have taken in previous lectures
If we take a midsagittal section of the head and neck we can see"flax cerebri" which attached anterior to
"Crista galli"of ethmoid bone, it's upper margin convex and contains the "superior sagittal sinus" and it's lower free margin contains "inferior sagittal sinus"
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As we said before that superior sinus drains into transverse sinus so transverse sinus receives:
1. Straight sinus
2. Inferior sagittal sinus
3.vein of Galen " great cerebral vein" which drain diencephalon " thalamus & hypothalamus"
It's very important because if it's blocked thalamus & hypothalamus will loss their function.
We know that left and right cerebral hemispheres connect with each other by corpus callosum
The posterior portion of corpus callosum called "splenium" and the anterior called "genu".
Let's talk about ventricles:
*The cavity between pons & cerebellum is 4th ventricle which connect with 3rd ventricle with
"aqueduct of Sylvius"
* On both side of 3rd ventricle we can see thalamus and hypothalamus so they always wash with CSF.
* 3rd ventricle open to lateral ventricles through "interventicular foramen" = "foramina of Monro"
* The CSF drains from lateral ventricles then to 3rdventricles after that to the 4thventricle which drain it into 3 places:
1.Central canal of the spinal cord
2. Left foramen of Luschka
3. Right foramen of luschka
These foramens retain the CSF to subarachnoid space
* Posterior horn of lateral ventricles descend to emotion area "hippocampus" which exist in the temporal pole
**pole means the prominent part of the lobe
* CSF formed by choroid plexus which locate within 1st & 2nd ventricles in the floor but in 3rd in the roof
The Nose
-It's a pear-shaped cavity…narrow superior and wide inferior.
- It's communicating posteriorly with nasopharynx through "choana"
- It's divided into 2 nasal cavities by "nasal septum"
- Each cavity has:
1. Roof
2. Floor
3. Medial wall
4. Lateral wall
-Roof formed by the following:
- Nasal bone.
- Frontal bone.
- Ethmoide bone.
- Sphenoide bone.
-Floor(wide) Consists of:
Palatine process of maxilla
Horizontal plate of palatine bone.
-medial wall
Formed by 1 cartilage and 2 bones :
* The cartilage : "septal cartilage " which helps in the movement of the nose
* perpendicular plate of ethmoide bone .
* vomer bone .
It's usually deviated to the right side.
-lateral wall
We can divide it into 3 regions:
1.Vestibule: lined by modified skin and contains hair.
2. Respiratory region: lined by respiratory epithelium
Rich blood, red in color.
3. Olfactory region: yellow in color, poor blood supply
Function only when it becomes moist.
The features of lateral wall:
1. Superior choncha
2. Middle choncha
3. Inferior choncha
With 4 spaces:
1. spheno-ethmoidal recess
2. Superior meatus
3. Middle meatus
4. Inferior meatus
If we elevate the middle concha we will find elevation which is "Bulla ethmoidalis" it's a large mass of ethmoidal cell. Below it we will find a groove "Hiatus semilunaris" it's anterior part called "infunbidulum" it's receives frontal sinus and it's posterior part receives maxillary sinus.
Sphenoid sinus
Located in the body ofSphenoid above it we will found "sella turcica" where we found pituitary gland
Above those we will found optic chiasm.
The beginning of optic nerves in the retina called "optic disc" as the optic nerves leave the retina they cross through optic chiasma and they pass hypothalamus until they reach the visual cortex in the occipital lobe (areas 17,18,19) these areas only for vision but the specific analyzing done by the memory
So the relations of sphenoid sinus:
Superior: pituitary gland and optic chiasma
Anterior: nose
Lateral: cavernous sinuses
Finally we saw the pharynx and it's part
Nasopharynx, oropharynx, laryngopharynx
And the epiglottis and the doctor asked where is the glottis???
It's the vocal cords
Also u have to remember that the "cricoid cartilage" is the only complete ring cartilage in trachea and it's narrow anterior wide posterior.