Introduction to Splachnology Lecture - European University Cyprus

Anatomy II – MED 200  Body cavities Spaces within the body that help protect, separate & support internal organs Cranial cavity Thoracic cavity Abdomino –pelvic cavity  Body cavities Thoracic Cavity Formed by thoracic wall...

Anatomy II – MED 200  Body cavities Spaces within the body that help protect, separate & support internal organs Cranial cavity Thoracic cavity Abdomino –pelvic cavity  Body cavities Thoracic Cavity Formed by thoracic wall Pleural Pleural Cavities (left & right) cavity Pericardial Each contains 1 lung cavity Do not communicate with each Diaphragm Abdominal other cavity Mediastinum Pelvic Contains heart & great vessels cavity Sternum Heart in pericardial cavity Pleural Right Left Right Left cavity lung lung Pleura lung lung Mediastinum Spinal cord  Body cavities Abdominal cavity from diaphragm to superior margins of pelvis liver, stomach, spleen, small intestine & most of large intestine Pelvic Cavity Bordered by pelvis Reproductive organs, urinary bladder, final portion of large intestine  The 11 body systems 1. Skeletal 2. Muscular 3. Nervous 4. Lymphatic 5. Cardiovascular 6. Respiratory 7. Digestive 8. Urinary 9. Reproductive 10. Endocrine 11. Integumentary  Cardiovascular body system Major Elements Heart Blood Blood vessels Functions Distributes blood cells, water & dissolved materials (eg nutrients, waste products, oxygen & CO2) Distributes heat & helps to control body temperature  circulation Pulmonary Pulmonary Pulmonary artery vein Venous Arterial circulation (Superior & Inferior vascularization circulation (Aorta) Somatic vena cava) Capillary bed  Respiratory body system Major Organs Nasal cavities Sinuses Larynx, Trachea, Bronchi Lungs Functions Deliver air to alveoli for gas exchange Provide oxygen to bloodstream Remove CO2 from bloodstream Produce sounds for communication  Digestive body system Major Organs Gastrointestinal track Teeth, Tongue, Pharynx Esophagus Stomach Small & large intestine Gastrointestinal glands Liver Gallbladder Pancreas Functions Process & digest food Absorb & conserve water Absorb nutrients Store energy reserves  Reproductive body system (male) Major Organs Testes Epididymides Ductus deferentia Seminal vesicles Prostate gland Penis Scrotum Functions Sperm production Production of hormones & nutrient fluids  Reproductive body system Major Organs Ovaries Uterine tubes Uterus Vagina Breast Functions Oocyte production & hormones Support developing embryo from conception – delivery Provides milk for newborn nourishment  Urinary system Major Organs Kidneys Ureters Urinary bladder Urethra Functions Excretes waste products from blood Controls water balance by regulating urine volume Stores urine prior to voluntary elimination Regulates blood ion concentrations and pH  Endocrine body system Major Organs Pituitary gland Pancreas Gonads Thyroid gland Adrenal glands Endocrine tissues in other systems Functions Directs long-term changes in activities of other organ systems Adjust metabolic activity & energy use by body Controls many structural & functional changes during development  Nervous body system Major Organs Brain Spinal cord Peripheral nerves Sensory organs Functions Directs immediate response to stimuli Coordinates/moderates activities of organ systems Carries & interprets sensory information  The nervous system Subdivisions ❖ Structural ❖ Central nervous system ❖ Brain ❖ Spinal cord ❖ Peripheral nervous system ❖ Spinal & cranial nerves ❖ Visceral nerves ❖ Enteric plexus ❖ Functional ❖ Somatic (innervates skin & muscles – generally subject to voluntary control) ❖ Autonomous – Innervate viscera Autonomic nervous system (ANS) > Innervates the internal organs (viscera) and other visceral elements, such as smooth muscle and glands, unconsciously. > It regulates visceral and glandular functions, playing a role in maintaining homeostasis. > It is concerned mainly with detecting and responding to information from the internal environment. > Acts independently- is involuntary in nature, meaning that we have no conscious control over it.  The autonomic nervous system ❖ Central part ❖ Peripheral part ❖ Sensory nerves monitor changes in the viscera (locate pain in a non localized manner, chemoreception, thermoreception, baroception) ❖ Motor nerves mainly innervate smooth muscle, cardiac muscle and glands ❖ Sympathetic part ❖ Parasympathetic part Visceral sensory and motor fibers enter and leave the CNS with their somatic equivalents  Subdivisions Sympathetic Nervous System (SNS) is the part of the ANS which is mostly active during stress. The Parasympathetic Nervous System (SNS) dominates during rest. The common phrase that describes the body state during SNS domination is “fight or flight”, while for the PSNS is “rest and digest”. Prepares the body for dealing with periods of increased physical activity helps the body to conserve energy  Visceral Nerve pathways The conduction of impulses from centers to periphery happens through a series of two neurons Preganglionic neuron Postganglionic neuron These two neurons meet and synapse in an autonomic ganglion. Ganglion: is a neural tissue outside of the CNS which comprises of the neuronal bodies. Synapsis: The junctions between neurons. Neurons connect with each other at synapses. They are usually formed between axons of presynaptic neurons and the dendrites and/or cell bodies of post-sysnaptic neurons. Neurotransmitters: The synaptic separation is overcome by chemical messengers called the neurotransmitters. They are released from presynaptic axons when action potentials reach their terminal structures. The neurotransmitter then crosses the synaptic cleft to attach to and activate receptors on the post-synaptic neuron.  Sympathetic & Parasympathetic Nervous System The central part of the ANS consists of centers within the brainstem and the spinal cord The peripheral part is made up of autonomic fibers and ganglia of the Peripheral Nervous System.  Basic arrangement of nervous system Visceral sensory and motor fibers enter and leave the CNS with their somatic equivalents Anterior rami Visceral sensory fibers enter the spinal cord together with somatic sensory fibers Spinal through posterior nerve roots of spinal nerves. Preganglionic fibers of visceral motor neurons exit the spinal cord in the Spinal cord Posterior anterior roots of spinal nerves, along rami with fibers from somatic motor neurons.  Ganglion White ramus Postganglionic fibers traveling Grey ramus to visceral elements in the periphery are found in the posterior and anterior rami (branches) of spinal nerves.  Sympathetic system nerve roots Sympathetic nerve roots leave the thoracolumbar regions with the somatic components of spinal nerves T1-L2. Then follow a synapse inside a ganglion  Sympathetic system ganglia Paravertebral ❖ Cervical ganglia ❖ C1 – C3 ❖ Thoracic ganglia ❖ T1-T12 ❖ Lumbar ganglia ❖ L1-L4 ❖ Sacral ganglia ❖ S1-S4/5 ❖ Ganglion impar (terminal)  Sympathetic system ganglia Prevertebral ❖ Celiac ganglia ❖ Superior mesenteric ganglia ❖ Inferior mesenteric ganglia  Sympathetic system Preganglionic Once in the chain preganglionic fibers may follow any of three routes: Some fibers synapse immediately with post ganglionic neurons. Some travel up or down the chain before synapsing. Some pass through the chain (without synapsing) and continue as splachnic nerves to nearby collateral ganglia for synapsing instead.  Sympathetic system Postganglionic From the ganglia long postganglionic fibers run all the way to target organs. Postganglionic fibers travel adjacent to arteries until their targets Sympathetic system Sympathetic system Sympathetic system Sympathetic system Sympathetic system Sympathetic system  Parasympathetic system nerve roots Parasympathetic nerve roots leave the CNS only with cranial nerves and spinal nerves S2-S4.  Parasympathetic system (PSNS) The cell bodies of the PSNS are in the brainstem and S2-S4 segments of the spinal cord. The peripheral part of the parasympathetic nervous system is divided into cranial and sacral outflows. PSNS has its ganglia placed near target organs of the abdomen and added to the branches of cranial nerves. Cranial outflow: The preganglionic fibers exit the brainstem within the oculomotor, facial, glossopharyngeal, and vagus cranial nerves. They synapse in the ciliary, pterygopalatine, otic, submandibular, and enteric ganglia. Postganglionic fibers innervate salivary, mucus, lacrimal glands, iris and ciliary muscles of the eye and The vagus nerve, thoracic and abdominal viscera. Sacral outflow: Preganglionic exit the spinal cord through the anterior roots of the S2-S4 spinal nerves. They travel with the pelvic splanchnic nerves. They synapse with PSNS ganglia found on or in the walls of their target organs. Inervate the pelvic viscera (descending colon, sigmoid colon, rectum, bladder, penis/clitoris). Brain Cranial nerves Parasympathetic ganglia Targets III, VII, IX Head (lacrimal glands, salivary glands, mucosae) Abdominal viscera X Spinal cord Pelvic nerves Targets Pelvic viscera  Autonomic nervous system Visceral sensory innervation ❖ Visceral sensory fibers generally accompany visceral motor fibers ❖ Sympathetic: Visceral sensory fibers that accompany sympathetic (motor) fibers are mainly concerned with detecting pain. ❖ Parasympathetic: Visceral sensory fibers associated with parasympathetic (motor) fibers primarily relay information to the CNS about the status of normal physiological processes and reflex activities.  The enteric system Enteric innervation ❖ Gastrointestinal track & viscera have their own, complex neural network (motor & sensory neurons) ❖ Myenteric plexus ❖ Submucosa plexus ❖ Ganglia within the walls of the gastrointestinal tract ❖ Extent ❖ More neurons than in the spinal cord ❖ In case of interruption of autonomous innervation, enteric system can work completely independently  Clinical implications Horner syndrome ❖ Interruption of the symptathetic inervation unilaterally ❖ Many causes, commonest one tumor interrupting vertebral chain ❖ Symptoms ❖ Ptosis (fall of upper eyelid) ❖ Miosis (small pupil) ❖ Anhidrosia (no sweating)  Lymphatic body system Major Organs Spleen Thymus Lymphatic vessels Lymph nodes Tonsils Functions Defend against infection & disease Returns tissue fluids to bloodstream  Collect fluid lost from vascular capillary beds during nutrient exchange processes Deliver it back to the venous side of the vascular system Lymphatic vessels Extensive and complex inter connected network of channels. This network begins as "porous“ blind- ended lymphatic capillaries in tissues of the body and converge to form a number of larger vessels. Ultimately these larger vessels connect with large veins in the root of the neck. Lymphatic vessels Lymphatic capillary Lymphatic vessel Lymph node Lymphatic vessel Lymphatic trunk Collecting duct Junction of Subclavian vein & internal jugular vein  Major & lesser thoracic duct ❖ Concentration of lymphatics throughout the body ❖ Drainage at subclavian vein ❖ Major thoracic duct → Left head, left arm, abdomen, pelvis, legs ❖ Lesser thoracid duct → Right arm, right chest, right head Lymph nodes Small (0.1- 2.5 cm long) encapsulated structures that interrupt the course of lymphatic vessels. They contain elements of the body's defense system: clusters of lymphocytes and macrophages. They act as filters that trap and phagocytose particulate matter in the lymph that percolates through them. They detect and defend against foreign antigens that are also carried in the lymph. Inside a lymph node is a honeycomb of connective tissue with spaces filled with WBC specialized for defense Clinical implications Cancer metastasis Clinical implications Lymphedema Information on the lesson Lesson organization Lectures Labs Assignment Exams  Lectures ❖ 3h/week ❖ Modules ❖ Respiratory ❖ Cardiovascular ❖ Digestive ❖ Urinary ❖ Reproductive (male/female)  Labs ❖ 3h/week ❖ Modules ❖ Models lab ❖ Sectra lab ❖ CAL  Assignment ❖ End of the semester ❖ Team group/teamwork ❖ Original subject ❖ Team grade ❖ Single speaker  Exams ❖ Midterms & Finals (70%) ❖ Written/CAL ❖ Practical ❖ Assignment (20%) ❖ Class participation/Viva Voca (10%)  Recommended textbooks ❖ Gray's Anatomy for Students; Richard Drake, A. Wayne Vogl & Adam W. M. Mitchell. Elsevier, 3rd ed., 2015 ❖ Netter, FH, Atlas of Human Anatomy. Elsevier, 6th ed., 2014 ❖ Virtual dissector of your choice