Human Anatomy Lecture 16 - Almaaqal University 2ed Year PDF

Academic year 2022-2023 ‫فرع جراحة الفم والوجه والفكين‬ ‫كلية طب االسنان‬ 2ed year Human Anatomy Lecture 16 The internal struc...

Academic year 2022-2023 ‫فرع جراحة الفم والوجه والفكين‬ ‫كلية طب االسنان‬ 2ed year Human Anatomy Lecture 16 The internal structure of the cerebral hemisphere Basal ganglia By:Dr.Nada hashim AL JASSIM Snell R.S. Clinical Anatomy by regions, 9th Edition, Lippincott Williams & Wilkins, [2012 For more detailed instructions, any question, cases need help please post to the telegram group of the session Subcortical structures Subcortical structures are a group of neural formations deep within the brain which include the Diencephalon, Pituitary gland, Limbic structures and the Basal ganglia. They are involved in processing and relaying neural impulses between the different parts of the brain The internal structure of the cerebral hemisphere The interior matter of the cerebral hemisphere is the white matter (nerve fibers of the pyramidal cells) with collections of gray matter scattered within the white matter which are called the basal ganglia , they are part of extrapyramidal system and play an important role in the control of posture and voluntary movement. The basal ganglia : the principle anatomical units of basal ganglia include: 1- Corpus striatum: which is divided by internal capsule into Caudate nucleus & Lentiform Nucleus 2-Lentiform nucleus: which consists of ; a-putamen. b-globus pallidus.. Basal ganglia are made up of the following pairs of nuclei: 1-caudate nucleus, 2- putamen, 3-globus pallidus, 4-claustrum, substantia nigra and subthalamic nucleus. The substantia nigra (midbrain) & subthalamic nucleus (Diencephalon) are not anatomical constituents of the basal ganglia, but functionally they belong together. The putamen and globus pallidus form the lentiform nucleus. The lentiform nucleus and caudate nucleus together are also known as the Corpus Striatum and they are separated by a sheet of white matter called internal capsule 1-Lentiform nucleus It is a mass of grey matter wedge-shaped,oval or (biconvex lens). It has 2 capsules, external capsule laterally & internal capsule medially. Internal capsule separates between lentiform nucleus laterally & caudate nucleus and thalamus medially. External capsule separates between lentiform nucleus and Claustrum. It is divided into Putamen & globus pallidus. Putamen :Large, dark or reddish in colour, lateral portion. Globus pallidus : Smaller, conical, lighter or yellowish in color , Its divided into two segments: the internal (or medial) segment and the external (or lateral) segment. -Inferiorly putamen is continuous with the head of caudate nucleus. 2-Caudate nucleus Large C-shaped or comma-shaped mass of grey matter. Lies in close relation to lateral ventricle. It has a big Head, Body, and Tail. Head :( Anterior) Large, & rounded and forms the lateral wall of anterior horn of lateral ventricle. It is continuous inferiorly with putamen of lentiform Nucleus. Body : Long &narrow continuous with head at the interventricular foramen,curving around the lateral part of the thalamus. It forms part of the floor of body of lateral ventricle. Tail : Long & narrow, and lies in the roof of inferior horn of lateral ventricle. It is connected anteriorly with Amygdaloid nucleus ❖ Note :A lesion to the caudate nucleus------Parkinsonism 3- Amygdaloid nucleus  Almond-shaped small mass of grey matter  lies in temporal lobe close to the Uncus.  Lies Anterosuperior to inferior horn of lateral ventricle.  It is connected to the tail of caudate nucleus.  It is joined to the lower convexity of putamin It is the smell center & part of limbic system. 4-claustrum  Thin sheet of gray matter which lies lateral to putamin and external capsule & medial to the Insula, with a thin layer of white matter (association fibers called external capsule) in between The dural venous Sinuses sinuses are venous channels found between the endosteal and meningeal layers of dura mater in the brain. They receive blood from the cerebral veins, receive cerebrospinal fluid (CSF) from the subarachnoid space via arachnoid granulation. And mainly empty into the internal jugular vein. They are valveless, allowing for bidirectional blood flow.These include: 1-Superior Sagittal Sinus : Located in the base of the falx cerebri and runs between the foramen caecum and internal occipital protuberance. 2-Inferior Sagittal Sinus : Located in the free border of the falx cerebri. 3-Straight sinus : Lies within the posterior end of the falx cerebri and in the middle of the tentorium cerebelli. 4-Sphenoparietal Sinuses (Left & Right): Located along the free border of the lesser wing of the sphenoid bone of the skull 5-Cavernous sinuses (Left & Right): Located on either side of the sella turcica of the sphenoid bone of the skull. 6-Superior Petrosal sinuses (Left & Right): They run along the petrous part of the temporal bone in the base of the tentorium cerebelli, terminating in the sigmoid sinus. 7-Inferior Petrosal sinuses (Left & Right): They exit the cavernous sinus and terminate in the sigmoid sinus. 8-Occipital sinus: Located within the fixed part of the falx cerebelli, running from the foramen magnum towards the internal occipital protuberance. 9-Transverse sinuses (Left & Right): Travel in the base of the tentorium cerebelli, from the confluence of sinuses to the Sigmoid sinuses. 10-Sigmoid sinuses (Left & Right): Located along the posterior cranial fossa, originating from the transverse sinuses and ending in the jugular foramen via the jugular bulb THANK YOU