Nervous System Lecture Notes PDF

Lecture Nervous System by Dr/ Mennat Allah Saqr MBBS, MS, PhD Lecturer, Anatomy and Embryology Department, Faculty of Medicine, Alexandria University.  OBJECTIVES :By the end of this lecture, the s...

Lecture Nervous System by Dr/ Mennat Allah Saqr MBBS, MS, PhD Lecturer, Anatomy and Embryology Department, Faculty of Medicine, Alexandria University.  OBJECTIVES :By the end of this lecture, the students should be able to.Classify the nervous system.1.Relate the different parts of the brain to their function.2.Differentiate between spinal and cranial nerves.3.Relate the two divisions of autonomic nervous system to their origin.4  Nervous system Central Peripheral (CNS) (PNS) Somati Brain c Spinal Autonomi cord c Nervous system I. Central Nervous System  I. Central nervous system (CNS) It is subdivided into: A. Brain - It occupies the cranial cavity. - It is formed of: 1.Cerebrum (Two cerebral hemispheres) 2.Brain stem 3.Cerebellum. B. Spinal cord - It occupies the upper 2/3 of the vertebral canal. A. Brain  A: Brain Site: It lies inside the skull (cranial cavity  A: Brain Coverings: - The brain is covered by the following three meninges: Dura, arachnoid, and pia maters. Parts: - The brain is formed of: 1.Cerebrum (Two cerebral hemispheres) 2.Cerebellum 3.brain stem. A: Brain  Coverings of the brain The brain is covered by three meninges: Dura, arachnoid, and pia maters. The space between the arachnoid mater and the pia matter space filled with cerebra-spinal fluid (CSF)  1. Cerebrum (Cerebral hemispheres) Parts: - It is formed of two cerebral hemispheres connected to each other in the midline. - Each hemisphere is formed of four lobes: 1. Frontal lobe (motor function) 2. Parietal lobe (sensory function) 3. Temporal lobe (hearing, smell, taste) 4. Occipital lobe (vision)  1. Cerebrum (Cerebral hemispheres)  2. Cerebellum - It lies below the posterior part of the cerebral hemispheres (occipital lobe). Functions: 1. Regulation of muscle tone. 2. Regulation of equilibrium. 3. Coordination of movements. 2. Cerebellum  3. Brain Stem - It lies in the base of the brain, and is continuous downwards with the spinal cord. Parts: It is formed of: 1.Midbrain 2.Pons 3.Medulla oblongata. Function: It contains the following centers: 1. Respiratory center. 2. Cardiovascular center. 3. Nuclei of cranial nerves. 3. Brain Stem 3. Brain Stem A. Spinal Cord Site: B. Spinal Cord - It lies inside the vertebral canal of the vertebral column. Beginning: - It begins at the lower end of the medulla oblongata (at the foramen magnum). Termination: - It terminates at the second lumbar vertebra (L2). Function: - It gives the peripheral and autonomic nerves. - It is also responsible for the reflex arc. B. Spinal Cord Reflex Arc II. Peripheral Nervous System  Peripheral Nervous System Somatic Autonomic Cranial Spinal nerves Parasympatheti nerves (12 Sympathetic (31 pairs) c pairs)  II. Peripheral nervous system (PNS) It is subdivided into: A. Somatic nervous system which is composed of: - Cranial nerves (12 pairs). - Spinal nerves (31 pairs). B. Autonomic (splanchnic) nervous system which is composed of: - Sympathetic nervous system. - Parasympathetic nervous system.  II. Somatic Nervous System A: Cranial nerves (12 pairs): - They supply the head and neck B: spinal nerves (31 pair of nerves): - Cervical nerves (8 pair): They supply the neck and upper limb. - Thoracic nerves (12 pair): They supply the thorax and abdomen. - Lumbar nerves (5 pair): They supply the abdomen and lower limb. - Sacral nerves (5 pair): They supply the pelvis and lower limb. - Coccygeal nerve (1 pair): It supplies small part of the pelvis. a) Cranial Nerves These are 12 pair of nerves that arise from the brain. They leave the cranial cavity through foramina in the skull. They control mainly the head & neck, thoracic and some abdominal viscera. b) Spinal Nerves: The spinal nerves are named according to the region of the spinal cord from which they originate. - Cervical nerves (8 pair): They supply the neck and upper limb. - Thoracic nerves (12 pair): They supply the thorax and abdomen. - Lumbar nerves (5 pair): They supply the abdomen and lower limb. - Sacral nerves (5 pair): They supply the pelvis and lower limb. - Coccygeal nerve (1 pair): It supplies small part of the pelvis.  C. Autonomic Nerves The Sympathetic Nervous System: Origin: Thoraco-lumbar outflow. The Parasympathetic Nervous System: Origin: Cranio-sacral outflow.  C. Autonomic Nerves They supply the viscera as the heart, bronchi, and smooth muscles. It is distributed through the central and peripheral nervous system. C. Autonomic Nerves  The sympathetic nervous system: The activities of the sympathetic nervous system prepare the body for emergencies (fight & flight). It increases the heart rate, increases the blood pressure, inhibits the peristaltic movements of the intestine and closes the sphincters.  B- The parasympathetic nervous system: The activities of the parasympathetic nervous system is to (rest & digest) It slows the heart rate, increasing the movements of the intestine and opening the sphincters. Wait a moment Identify the structure 1. To which part of the nervus system dose it belong? Identify the lobe number 2. Mention its function ? Identify the lobe number 3. Mention its function ?. Identify the lobe number 4 Mention its function ? Identify the lobe number 5 Mention its function ? Identify the structure number 6 Mention its functions ? Identify the structure number 7 Mention its Parts?