Veterinary Anatomy I CVM 710 Fall 2022 PDF

Veterinary Anatomy I: CVM 710: Fall 2022 020 –ANS part 2: Parasympathetic Learning Objectives Dr. Ismael Concha-Albornoz [email protected] www.anato.cl 1. Distinguish the “somatic” and “autonomic” nervous systems. 2. Compare and contrast the divisions of the autonomic nervous system (Paras...

Veterinary Anatomy I: CVM 710: Fall 2022 020 –ANS part 2: Parasympathetic Learning Objectives Dr. Ismael Concha-Albornoz [email protected] www.anato.cl 1. Distinguish the “somatic” and “autonomic” nervous systems. 2. Compare and contrast the divisions of the autonomic nervous system (Parasympathetic & sympathetic) 3. Describe/diagram the pathways for the various body regions and divisions of the ANS. Divide the pathway into preganglionic and postganglionic portions and indicate the most likely location where the synapse between preganglionic and postganglionic neurons would occur. 4. Identify the vagus nerve in the thorax. Observe the organ with direct relationship with vagus n. in the cranial, middle and caudal mediastinum. 5. Describe the relationship between the sympathetic trunk and the vagus nerve to form the vagosympathetic trunk. 6. Describe the divisions of the vagus nerve in dorsal and ventral branches. Explain how the dorsal branches (right and left) joint together to form the dorsal vagal trunk. Do the same with the ventral branches and the ventral vagal trunk. 7. Describe the origin of the right versus the left recurrent laryngeal nerve (branch of vagus nerve) 8. Explain how parasympathetic nerves innervate pelvic organs. Describe the pelvic nerve and pelvic plexus 9. Define hypogastric nerve Nervous System Anatomical distribution Physiological distribution Somatic Nervous System (SNS) (voluntary, squeletic muscles) Autonomic Nervous System (ANS) (involuntary or visceral) - Smooth m. (Non striated) - Heart - Glands Biosphera.org General Visceral Efferent Sympathetic & Parasympathetic Responsible for control of involuntary or visceral bodily functions: Plays a key role in the body response to stress • • • • • Cardiovascular Respiratory Digestive Urinary Reproductive functions General Visceral Efferent Parasympathetic Responsible for control of involuntary or visceral bodily functions: Stress General Visceral Efferent Parasimpathetic General Visceral Two pathways to produce a visceral effect: Sympathetic & parasympathetic In each pathway two Efferent neurons are needed to innervate the target organ Parasympathetic Nucleus Preganglionic or presynaptic neuron Nucleus Preganglionic or presynaptic neuron Ganglion Postganglionic or postsynaptic neuron Intramural ganglia & postganglionic neuron Ganglion Postganglionic or postsynaptic neuron General Visceral Efferent Smooth, Cardiac muscles & glands Parasympathetic nuclei brainstem Cranial nerves Preganglionic neuron (Vagus nerve) Spinal cord Brainstem 1st Neurotransmitter: Acetylcholine Ganglion Intramural (within the wall of the target organ) Postganglionic neuron Intramural (within the wall of the target organ) 2nd Neurotransmitter: Acetylcholine Biosphera.org General Visceral Efferent Smooth, Cardiac muscles & glands Parasympathetic nuclei Sacral segments Parasympathetic nuclei brainstem Cranial nerves Spinal cord Brainstem Preganglionic neuron (Vagus nerve) Preganglionic neuron (Pelvic nerve) Pelvic ganglia 1st Neurotransmitter: Acetylcholine Postganglionic neuron Ganglion Intramural (within the wall of the target organ) Postganglionic neuron Intramural (within the wall of the target organ) 2nd Neurotransmitter: Acetylcholine Biosphera.org General Visceral Efferent Parasympathetic Motor Nuclei Cranial nerves Ciliary ganglion Motor Nuclei S1 –S3 Spinal cord Brainstem III VII Pterigopalatine ganglion IX X: VAG U Otic ganglion Mandibular ganglion Pelvic n. Inferior ganglion of cranial nerve X (vagus) Pelvic ganglia S NERV E Intramural ganglia Intramural ganglia Smooth, Cardiac muscles & glands Parasympathetic Nervous System CN: Cranial Nerve • CN III, VII, IX – Covered with the head • CN X (vagus n.) – thoracic and abdominal organs • Sacral spinal cord – pelvic organs CN X: Vagus Nerve Cervical, Thoracic, and Abdominal Viscera Thorax & cervical regions • Preganglionic Pathway: parasympathetic nucleus of vagus nerve → vagus nerve → vagosympathetic trunk → vagus nerve → vagal branches → cardiac nerves to heart, lungs → recurrent laryngeal nerves to cervical organs like esophagus, trachea and larynx. Note: recurrent laryngeal n. also carries GSE & GSA. Is the main motor nerve for the skeletal mm. of the larynx • Ganglion: terminal ganglia (within organs innervated) → • Postganglionic Pathway: within organ CN X: Vagus Nerve Cervical, Thoracic, and Abdominal Viscera Left subclavian a. Aortic arch Dorsal branch of vagal nerve Ventral branch of vagal nerve esophagus Vagus n. CN X: Vagus Nerve Cervical, Thoracic, and Abdominal Viscera Abdomen • Preganglionic Pathway: parasympathetic nucleus of vagus nerve → vagus nerve → vagosympathetic trunk → vagus nerve → dorsal & ventral vagal branches → dorsal & ventral vagal trunks → dorsal vagal trunk joins celiacomesenteric plexus via celiac branch → ventral vagal trunk goes directly to stomach and liver • Ganglion: terminal ganglia (within organs innervated) → • Postganglionic Pathway: within organ Dorsal view of the vagus nerves in the thorax Left vagus n. Trachea Right Recurrent laryngeal n. Right vagus n. Dorsal vagal branch Esophagus Left Recurrent laryngeal n. Dorsal vagal branch Ventral vagal branch Ventral vagal branch Diaphragm Esophageal hiatus Abdomen CN X: Vagus Nerve Cervical, Thoracic, and Abdominal Viscera Dorsal vagal trunk Left subclavian a. Aortic arch Dorsal branch of vagal nerve Mixture of right and left dorsal vagal branches Ventral vagal trunk Ventral branch of vagal nerve Mixture of right and left ventral vagal branches Dorsal view of the vagus nerves in the thorax Left vagus n. Trachea Right Recurrent laryngeal n. Right vagus n. Dorsal vagal branch Esophagus Left Recurrent laryngeal n. Dorsal vagal branch Ventral vagal branch Ventral Vagal Trunk Ventral vagal branch Dorsal vagal Trunk Diaphragm Esophageal hiatus Ventral Vagal Trunk Dorsal vagal Trunk Abdomen CN X: Vagus Nerve Cervical, Thoracic, and Abdominal Viscera * Head Tail Right recurrent laryngeal nerve Right subclavian a. CN X: Vagus Nerve Cervical, Thoracic, and Abdominal Viscera Dorsal branch of vagal nerve Di Head * Dorsal vagal trunk m ag hr ap Ventral vagal trunk Left recurrent laryngeal nerve Ventral branch of vagal nerve Tail CN X: Vagus Nerve Cervical, Thoracic, and Abdominal Viscera Dorsal vagal trunk Left subclavian a. Aortic arch Dorsal branch of vagal nerve Mixture of right and left dorsal vagal branches Ventral vagal trunk Ventral branch of vagal nerve Mixture of right and left ventral vagal branches CN X: Vagus Nerve Cervical, Thoracic, and Abdominal Viscera a. Stomach, spleen ic nter ese Cr. M Celiac a. Aorta Stomach, spleen, liver, gallbladder, pancreas, kidneys, small and large Intestines until transverse colon Ganglia & Postganglionic neuron Intramural (within the wall of the target organ) General Visceral Efferent Parasympathetic Motor Nucleus S1 –S3 Motor Nucleus Ciliary ganglion Spinal cord Brainstem III VII Pterigopalatine ganglion Inferior ganglion of X IX X: VAGUS NERVE Otic ganglion Mandibular ganglion Smooth, Cardiac muscles & glands Sacral Spinal Cord: S1-S3 GVE-Parasympathetic to Pelvic Organs • Preganglionic Pathway: intermediate gray matter (S1-S3) → ventral root → spinal nerve → ventral branch → lumbosacral plexus→ pelvic nerve → pelvic plexus Pelvic nerve (S1-S3) Pelvic ganglia/ pelvic plexus Sacral Spinal Cord: S1-S3 GVE-Parasympathetic to Pelvic Organs • Preganglionic Pathway: intermediate gray matter (S1-S3) → ventral root → spinal nerve → ventral branch → lumbosacral plexus→ pelvic nerve → pelvic plexus Pelvic nerve (S1-S3) Aorta Postganglionic Pathway: branches from pelvic plexus to pelvic organs Rectum Hypogastric nerve Internal iliac a. Internal pudendal a. Pelvic ganglia/ pelvic plexus Sacral Spinal Cord: S1-S3 GVE-Parasympathetic to Pelvic Organs • Preganglionic Pathway: intermediate gray matter (S1-S3) → ventral root → spinal nerve → ventral branch → lumbosacral plexus→ pelvic nerve → pelvic plexus Pelvic nerve (S1-S3) Postsynaptic sympathetic Rectum Hypogastric nerve Presynaptic sympathetic Aorta Hypogastric nerve Pre & post sympathetic nerves toward the pelvic plexus Internal iliac a. Internal pudendal a. Pelvic ganglia/ pelvic plexus Pelvic nerve Pelvic ganglia/ pelvic plexus Hypogastric nerve Pre & post sympathetic nerves toward the pelvic plexus Celiacomesenteric plexus/ ganglia Sympathetic nerves connecting visceral ganglia Hypogastric nerves Parasympathetic Erection Sympathetic Ejaculation