control and coordination L-3.pptx for Neet

Control and co ordination

1. REFLEX ACTION :- spontaneous , instant , involuntary action

2. SPINAL CORD – it is present inside neural canal or spinal canal of vertebral column 42 cm in female and 45 in male 3 meninges and csf provide additional protection Single , Hollow spinal cord filled with CSF It start with medulla and extent till 2 nd lumbar vertebra Because the growth of nervous system is majority limited to foetal life , and it reaches its Max size at 6 years . Whereas the vertebral column keeps on growing till 20 years of age Cord terminate as tapering conical str. Called conus medullaris Conus medullaris is connected to coccygeal end of vertebral coulmn by a fibrous connective tissue derived from pia mater called filum terminale Ascending and descending tract present Intervertebral foramen Cell body Myelinated

3. > Grey matter(inner zone) devide into 6 horns 2 Ventral / anterior horn 2 Posterior /dorsal horn 2 lateral horns Central canal lined by ependymal cells which is filled with CSF White matter(outer zone) is arranged in form Of columns/ funiculus 6 horns present white due to myelinated sheet

4. SPINAL NERVES :- Path of communication between spinal cord and other region of body Spinal nerves comes out from intervertebral foramen But since the length of spinal cord is shorter than vertebral column ,last portion of spinal nerves emerges as a cluster in horse tail structure called as cauda equina 31 pairs in human All are mixed nerves bcz have both Sensory , inter , motor nerves Spinal nerve is attached to spinal cord By 2 roots (dorsal –have ganglion that Consist group of cell body ) and (ventral It has motor neurons)

5. PERIPHERAL NERVOUS SYSTEM :- it lies along the peripheral region of body it consist of body associated with CNS It consist cranial (12) and spinal nerves (31 ) Transmit impulse from CNS to skeletal muscle Transmit impulse from CNS to involuntary organ CRANIAL NERVES :- 12 pairs in amniotes (reptiles/birds/mammals) 10 pairs in anamniotes (fishes/amphibians)

6. Retina to occiptal lobe (eyeball and upper eyelid , innervated muscles that change lens shape and constrict pupil) Smallest , thinnest Largest , originate from pons , has 3 branch - opthalmic , maxillary,mandible Touch , pain , teeth sensation E moji , expression , anterior 2/3 part of tongue, chewing Originate from medulla ,posterior 1/3 of tongue ,mucous membrane , pharynx,parotid Gland , taste and swallowing