Nervous system

  • 14 янв. 2011 г.
  • 1674 Слова
Nervous System
Consist of 2 types.
1) Central Nervous system (CNS)
a) Brain Occupies cranial cavity
b) Spinal cords occupies in vertebral canal
2) Peripheral Nervous system (PNS)
a- Somatic nervous system includes 12-pairs of cranial nerve & 31 pairs of spinal nerves.
b- Autonomic nervous system it consist of sympathetic & parasympathetic system

Consist of3-parts
Consist of
• 2 cerebral hemispheres & median part (cerebrum)
• Diencephalons (Thalamencephalon) this part is hidden by cerebrum diencephalons consist
⇨ Thalamus
⇨ Hypothalamus
⇨ Metathalamus
⇨ Epithalamus
⇨ Sub- Thalamus
2).Midbrain. connection between forebrain & hindbrain
Include pons,cerebellum, and medulla oblongata

CNS covers by3 layers
• Outer: dura mater
• Middle: Arachnoids mater
• Inner: Pia mater
Space between dura mater & arachnoids called subdural or epidural space between arachnoid & pia mater called subarchnoid space.

• Cerebrum:-Is largest part of brain consisting of 2 hemispheres which are connecting by white matter called corpus callosum. The surface layers called cortex which is grey color. On cortex there is many folds called gyrus. Gyri are separated by fissure called sulcus.
Each hemisphere contains lobes name are according to bones of skull.
⇨ Broca’s area or motor speech lies just above lateral sulcus.It controls speech or language. It is dominant in right handed person in left hemispheres & vise versa.
⇨ Visual area on posterior pole of cerebral hemispheres in the region of calcarine sulcus.
⇨ Wernickl’s area present in perital lobe function understanding of language.
⇨ Moter area,s is localized in precentral this large moter cells neurons which cross opposite side ofbody.they may be cross in medulla oblongata.
⇨ Auditory area present in superior temporal gyrus which receipt & interpretation the sound.
⇨ Sensory area in the post central gyrus which recept the sensory small neurons from opposite of body e.g. pain ,temperature ,touch ,pressure,
1. Hypothalamus!
Hypothalamic sulcus from front to back they are present
• Optic chiasm• Tuber Cinereum
• Infundibulum
• Mammillary bodies
• Posterior perforated substance
• Sympathetic & Para sympathetic center in anterior & posterior parts
• System center in hypothalamus e.g. respiratory center which include 1.inhitory center which inhibit respiration 2. stimulatory center that stimulate respiration
•Hunger center & thirst , vomiting center
• Sexual behavior & reproductive center
Lateral & medial geniculate body.
• Lateral geniculate body. Which is last relay station for vision center
• medial geniculate body. Which is last relay station for auditory center
3. EPITHALAMUS:-Right & left habenular nuclei, pineal glands.
Function for limbic system
Largest grey matter mass situated in the lateral ventricle.
• Anterior end with anterior nucleus
• Posterior end with boundary of interventricle foramen.
• Superior also 2 ends.
⇨ Laterally by centre of lateral ventricle limited to calculate nucleus.
⇨Medially by choroids of 3rd ventricle limited by habenular strai.
• Inferiorly by sub thalamus & hypothalamus
• Medially surface from posterior superior part of lateral wall of 3rd ventricle & also by medially 2 thalami adhesion.
• Laterally formed by medially boundary of posterior limb of internal capsule.
5.SUBTHALAMUS! Is situated ventral to dorsal thalamus or in front lateral...
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