L4 Nervous System PDF

Nervous system B.Vs- fascia Anatomy Department Learning objectives ✓ Discuses part of nervous system ✓ Describe central and peripheral nervous system ✓ Describe parts of spinal nerves ✓ Classify the fascia ✓ Describe characters of superficial and deep fascia ✓ Identify the difference between ar...

Nervous system B.Vs- fascia Anatomy Department Learning objectives ✓ Discuses part of nervous system ✓ Describe central and peripheral nervous system ✓ Describe parts of spinal nerves ✓ Classify the fascia ✓ Describe characters of superficial and deep fascia ✓ Identify the difference between arteries and veins The nervous system Itcontrols and integrates the activities of the different parts of the body. It is divided structurallyand functionally into two parts Structurally is divided into two main parts: The central nervous system and the peripheral nervous system Functionally, It can be further divided into the somaticnervous system and the autonomicnervous system. Functionally: the somatic nervous system controls voluntary activities the autonomic nervous system, which controls involuntary activities Central Nervous System: -It is brain and spinal cord -It is composed of large numbers of nerve cells (neuron) and their processes(axon and dendrites) The parts of the brain are the cerebral hemispheres, the cerebellum, and the brainstem midbrain, pons, and medulla. The spinal cord is the part of the CNS in the superior two thirds of the vertebral canal. It is roughly cylindrical in shape Meninges They are three connective tissue covering that surround, protect, and suspend the brain and spinal cord within the cranial cavity and vertebral canal, respectively: The dura mater is the thickest and most external of the coverings. The arachnoid mater is against the internal surface of the dura mater. The pia mater is adherent to the brain and spinal cord. Between the arachnoid and pia mater is the subarachnoid space, which contains CSF. Cerebrospinal fluid Peripheral Nervous System ❑ it consists of the cranial and spinalnerves and their associated ganglia. ❑ They are made up of bundles of neuron processes (axons) supported by delicate areolar tissue. ❑ A ganglion is a cluster of neuron cell bodies located outside the CNS. Cranial Nerves ✓ The 12 pairs of cranial nerves branch off the brain and upper spinal cord and pass through openings (foramina) in the skull. ✓ All the cranial nerves are distributed in the head and neck except cranial nerve (CN) X (vagusnerve),which also supplies structures in the thorax and abdomen. ✓ they are motor or sensory or mixed Spinal nerves ✓ A total of 31 pairs of spinal nerves leave the spinal cord and pass through intervertebral foramina ✓ The spinal nerves are named according to the region of the vertebral column with which they are associated: 8 cervical, 12thoracic, 5lumbar, 5sacral, and 1coccygeal ✓ The spinal nerves are mixed nerves Parts of spinal nerves Two roots connect the nerve to the spinal cord : 1-Posterior(dorsal)root: afferent (sensory) 2-Anterior root(ventral):efferent (motor) 3-Mixed nerve trunk: By union of both roots 4-Anterior ramus: supply muscle and skin of front and form plexus. 5-Posterior ramus: supply muscle and skin of back, not form plexus. Muscle Tone It is the characteristic firmness of the somatic muscle during rest, with elastic resistance to pressure Determination of the tone of a muscle is an important clinical examination. The muscle is flaccid (lost the tone) after injury of its motor nerve supply Superficial facia Anatomy of the fascia  Deep fascia General features: 1- strong fibrous investing the body beneath superficial fascia 2-dense, not elastic, devoid of fat 3- formed of regular arranged collagen fibers 4- its distribution a-Well-defined: in limbs and neck b-Ill-defined: in -face and the larger part of the  Special features (A) Extensions to (A) Extensions to form : form : 1-Septa between muscles of limb, dividing it into compartments 2- Muscle sheath: fascial covering of muscles 3-Fascial envelope for the neuro- vascular bundles ❖ Fascial envelope for the neuro-vascular bundles ❖ Muscle sheath ❖ Septa (B) Thickening to form: 1-Retinacula: They are thick bands of deep fascia around some joints, as the wrist and ankle. Thickened deep 2-Aponeurosis :- thick band facia of deep fascia, as palmar 3-Ligaments:- aponeuroses in palm and strong, inelastic plantar aponeuroses in sole. fibrous bands formed of thickening of deep fascia nearby joints to connect bones, as sternoclavicular and radioulnar ligaments  (C) Inturption of deep fascia ‫يعني مش موجودة‬ The subcutaneous parts of bones throughout the body are devoid of deep fascia as medial surface of tibia Anatomy of the blood vessels Blood circulation The heart pumps out the blood, through the arteries, to the capillaries in the tissue. It turns back again through the small veins then large veins,then to the heart again.  Arteries vs Veins Artery Vein Wall Thick wall Thin wall Lumen Narrow lumen Wide lumen Pressure High pressure Low pressure Pulsations Pulsatile Non pulsatile Carried blood Oxygenated Non oxygenated blood blood Except Except pulmonary, pulmonary veins. arteries. Valves No valves Valves Bleeding with Projectile Continous injury bleeding bleeding ‫ماشي مع النبضات‬ Pattern of Tree like River like  Bleeding Valves  Pattern of distribution River like in vein Tree like in artery