BIOLOGY ZNOTES

CENTRAL NEURAL SYSTEM (CNS) Central neural arrangement consists of 2 parts: Brain as well as Spinal cord A. BRAIN It is protected inwards cranial cavity. It has 3-layered connexion tissue membranes (outer dura mater, middle arachnoid mater as well as inner pia mater) called cranial meninges. The subarachnoid infinite (space betwixt pia mater as well as arachnoid mater is filled amongst cerebrospinal fluid (CSF). The ventricles of encephalon are also filled amongst CSF. Brain has three divisions: Forebrain, Midbrain as well as Hindbrain. a. Forebrain (Prosencephalon) It is the anterior part. It consists of cerebrum & diencephalon. Cerebrum It is the largest part. It has 2 cerebral hemispheres held together past times a thick tissue (Corpus callosum).  Each cerebral hemisphere has four lobes. They are Frontal lobe, Parietal lobe, Temporal lobe & Occipital lobe.  The cerebral cortex (outer portion of cerebrum) has many convulsions (gyri) & dep...

Name Types of fibre Organs innervated Functions 1.     Olfactory Sensory Olfactory mucus membranes Smell 2.     Optic Sensory Retina Vision 3.     Oculomotor Motor Eyeball muscles Eyeball movement, command ciliary muscles, tear gland 4.     Trochlear Motor Eyeball muscles Eyeball movement 5.     Trigemina l Mixed Skin, oral mucosa, muscles of head, face, mouth Cutaneous sensation, musculus movement 6.     Abducens Motor Eyeball muscles Eyeball movement 7.     Facial Mixed Taste buds, salivary glands, facial in addition to cervix muscles Taste, salivation, movement, tear secre...