Hbod Lab Last Exam PDF

# **Heart and the Circulatory System** ## **Middle Mediastinum** | Structure | Description | Function | |---|---|---| | Pericardial Sac (Pericardium) | Outer fibrous visible, inner serous layers not visible Located posteriorly to auricles | Protective covering of heart | | Right/Left Atrium: | |...

# **Heart and the Circulatory System** ## **Middle Mediastinum** | Structure | Description | Function | |---|---|---| | Pericardial Sac (Pericardium) | Outer fibrous visible, inner serous layers not visible Located posteriorly to auricles | Protective covering of heart | | Right/Left Atrium: | | Holding chamber for blood during venous return (particularly useful during high venous return to accommodate extra blood) | | Auricles (L/R) | Anterior surface, extend superiorly and laterally from atria | Holding chamber during high venous return | | Pectinate Muscle | Muscular ridges within the right and left auricles | Stretch to increase blood volume | | Tricuspid Valve (3 cusps) | Separates right atrium from right ventricle | Prevents reflux of blood into the right atrium | | Right/Left Ventricle: | Comprise majority of heart, esp. RV | Pressurize, pump blood into arteries | | Interventricular Septum | Thick wall separating the right and left ventricles | Myocardium provides the contractions of the ventricles and contains the electrical conduction pathway necessary to stimulate ventricular contraction | | Trabeculae Carneae | Associated with the inner walls of the ventricle | Prevent ventricles walls from sticking together during contraction | | Papillary Muscles (3 in right; 2 in left. Think about why this might be.) | Elevations of myocardium in ventricles | Regulate movement of valve cusps, helps assure proper closure of valves | | Chordae Tendineae | Fibrous strands attach edges of valve cusps to papillary muscles | Prevent "flipping" of valve cusps into atrium | | Pulmonary Semilunar Valve | Separates right ventricle from pulmonary trunk; valve with three cusps | Prevents reflux of blood into right ventricle | | Ligamentum Arteriosum | Remnant of ductus arteriosus, fibrous cord between pulmonary trunk to aortic arch | Fetal remanent (Ductus Arteriosus) structure which serves no purpose after fetal development but serves as an excellent landmark in the adult. During fetal development, the Ductus Arteriosus directly shunts the blood from the pulmonary arteries to the aorta. Why would this be necessary during fetal development? | | Pulmonary Trunk: | Emerges directly from RV, bifurcates into pulmonary arteries | Receives deoxygenated blood from right ventricle | | Pulmonary Arteries (L/R) | Vessels coming from the right ventricle | Carries deoxygenated blood from the right side of the heart to the lungs | | Pulmonary Veins | Vessels from the lungs to the left atrium | Brings oxygenated blood from lungs to left side of heart | | Bicuspid Valve (2 cusps) | Separates left atrium from left ventricle | Prevents reflux of blood into left atrium | | Aortic Semilunar Valve | Separates left ventricle from aorta; valve with three semilunar cusps | Prevents reflux of blood into left ventricle | ## **Vasculature of the Heart/Misc.** | Structure | Description | Function | |---|---|---| | Ascending Aorta | Emerges directly from LV, runs superiorly | Receives highly pressurized blood, contains root | | Aortic Arch: | Curved portion of ascending aorta | Passes blood to arteries, descending aorta | | Brachiocephalic Trunk of Aorta | First branch off aortic arch | Supplies head, neck, right brachium | | Right Common Carotid Artery | Medial branch of brachiocephalic trunk | Supply head and neck | | Right Subclavian Artery | Lateral branch of brachiocephalic trunk | Supply right brachium | | Left Common Carotid Artery | Second branch of aortic arch | Supply head and neck | | Left Subclavian Artery | Third branch of aortic arch | Supply left brachium | | Left/Right Brachiocephalic Veins | Formed by union of subclavian and internal jugular veins | Drains brachiums, brain, face, neck | | Superior Vena Cava | Formed by union of brachiocephalic veins, empties to RA | Drains brachiums, brain, face, neck, thoracic wall | | Coronary Sinus | Passes from left to right in posterior portion of heart | Receives blood circulating within the heart's muscle and returns it to the right atrium | | Inferior Vena Cava | Makes wall of right atrium | Largest vein in the body which returns blood from the lower portion of the body to the heart | | Thoracic Aorta | Part of descending aorta which is continuation of aortic arch | Conduct high pressure blood inferiorly | | Phrenic Nerve (lateral) | Originates at C3-C5 and passes between lung and heart to reach diaphragm | Important for breathing, passes motor information to diaphragm and receives sensory information from diaphragm | | Vagus nerve (CN X) (medial) | Paired, runs laterally along trachea/esophagus; phrenic nerve close | Sensory input, motor output to thoracic organs | | Diaphragm | Wide, flat, domed skeletal muscle under the lungs; Muscle separating thorax and abdomen | Primary muscle of respiration; With intercostals creates pressure differentials needed for filling the lungs | ## **Structures of the Lungs** | Structure | Description | Function | |---|---|---| | Lungs: | Paired, lobed, located laterally to the heart | House the bronchial tree, facilitates gas exchange (see reading for further information which Is fair game for the exam) | | Lobes: | | | | Apical/Superior | Most superior lobe of lung | *Know divisions, see function of the lungs | | Middle (Right lung only) | The middle or second lobe of the right lung | *Know divisions, see function of the lungs | | Diaphragmatic/Inferior | The most inferior lobe; superior to the diaphragm | *Know divisions, see function of the lungs | | Fissures: | | | | Oblique | Runs diagonally across the lung | *Know for ID | | Horizontal (Right lung only) | Runs horizontally across the lung | *Know for ID | | Hilum | Indentation in the medial aspects of the lungs | Passageway for bronchi and where arteries and veins enter the lungs | | Carina | Located a the bifurcation of the trachea | Senses foreign particles before entering the lungs | | Primary Bronchi | Branch off from trachea, rigid with cartilage rings | Conduction of air from trachea to lungs | | Secondary Bronchi | Branch off from primary bronchi | Moves air deeper into bronchial tree | | Tertiary Bronchi | Branch off from secondary bronchi | Moves air deeper into bronchial tree | | Bronchiole(s) | Very small, connects tertiary bronchi to alveoli as they become smaller | Moves air deeper into bronchial tree | | Alveoli | Small clusters which look like grapes | Site of gas exchange within the lungs | ## **Main Gastrointestinal Tract** | Structure | Description | Function | |---|---|---| | Esophagus | Extends from laryngopharynx to stomach | Passageway for food, contains an upper and lower esophageal sphincter located at the top/bottom of the esophagus respectively. | | Greater Omentum | Apron-like structure attached to stomach | Fat storage, insulation, and abdominal protection | | Stomach: | J-shaped organ connecting esophagus with duodenum | Passageway for food, area of digestion | | Cardia | Upper portion of the stomach closest to the esophagus | Contents from esophagus enter stomach | | Fundus | Upper curved part of stomach | Secretes digestive compounds, mixes gastric contents, peristaltic contractions to move contents toward pyloric sphincter | | Body | Large portion that is normally thought of as the stomach | Mixes gastric contents, helps form chyme | | Pylorus | Portion closest to pyloric sphincter | Secretes digestive compounds, mixes gastric contents | | Pyloric Sphincter | Anatomical sphincter separating stomach from duodenum | Regulates rate of chyme passage from stomach to duodenum | ## **Small Intestines:** | Structure | Description | Function | |---|---|---| | Duodenum | First part of SI, C-shaped, bends around pancreas | Primary site for digestion and absorption of nutrients Site of further enzymatic breakdown | | Jejunum | Second part of SI | Chemical digestion and nutrient absorption; | | Ileum | Last part of SI, longest portion of SI | Final stage of nutrient absorption; contains Peyer's patches which help protect against microorganisms | ## **Large Intestines:** | Structure | Description | Function | |---|---|---| | Cecum | Pouch-like beginning of LI | Main site of water absorption; initial electrolyte absorption; moves the digested material (feces) towards the rectum | | Ileocecal valve | A thick band of tissue which can be felt separate the lleum from the Cecum | Houses some bacteria, water/electrolyte absorption Serves as a sphincter muscle separating the large and small intestine. Helps prevent back flow of fecal matter into the Ileum. | | Appendix | Narrow "worm-like" structure extending from cecum | Training ground for new immune cells | | Ascending Colon | Right side, begins at ileocecal valve | Water/electrolyte, VFA (volatile fatty acid) absorption | | Transverse Colon | Crosses from right side to left side | Water/electrolyte absorption | | Descending Colon | Descends from left side to rectum | Water/electrolyte absorption, stores feces | | Sigmoid Colon | S-shaped, located in pelvic cavity | Water/electrolyte absorption, stores feces | | Rectum | The portion directly after the Sigmoid colon, the first portion of the "straight-away" towards the anus | Fecal storage before expulsion from the body | | Anal canal | Connects the rectum to the anus | Houses the external anal sphincter (adhered to the anus) which allows the voluntary passing of feces from the body | | Anus | Opening at end of the Anal canal | Final passage out of body for fecal waste | ## **Accessory Digestive Viscera** | Structure | Description | Function | |---|---|---| | Liver: | Large, dark organ superior to stomach, lobed | Detoxification, production of bile, responds to glucagon to raise blood sugar (see pancreas). | | Right Lobe | Right portion of liver | | | Left Lobe | Left portion of liver | | | Caudate Lobe | Medial, superior posterior lobe next to the inferior vena cava | *Know the location of lobe | | Quadrate Lobe | Medial, inferior posterior lobe next to the gallbladder; "square" in shape | *Know the location of lobe | | Gallbladder | Small, greenish sac nestled inferior aspect of liver | Stores and concentrates bile. | | Pancreas | Nested in curve of duodenum, extends to left side | Produces & secretes enzymes and hormones * Endocrine: * Insulin: signal glucose uptake in cells to lower blood glucose * Glucagon: signal glycogen conversion to glucose in liver to raise blood glucose * Somatostatin: an inhibitory hormone affecting many things, but in digestion is responsible for: inhibiting the release of insulin/glucagon, suppressing exocrine function of pancreas, and slowing gastric emptying/SM contraction * Exocrine (digestion): HCO3- (bicarbonate for pH balance) and digestive enzymes | | Spleen | Lateral to stomach, superior to pancreas | Lymphatic organ, aids immune system, RBC breakdown | ## **Arterial Supply for GI Tract** | Structure | Description | Function | |---|---|---| | Abdominal Aorta: | Largest artery in abdominal cavity | Supplies abdomen and lower limbs with blood | | Celiac Trunk | First unpaired branch off abdominal aorta | Supplies blood to stomach, liver, spleen, and superior portions of duodenum and pancreas | | Superior Mesenteric Artery | Second unpaired branch from abdominal aorta | Supplies blood to transverse colon, cecum, ascending colon, ileum, and jejunum | | Inferior Mesenteric Artery | Third unpaired branch of abdominal aorta | Supplies blood to descending colon, rectum, and anus | | Hepatic Portal System | The joining of four veins into a large vessel known as the hepatic portal vein (Hepatic, Splenic, Superior Mesenteric, and Inferior Mesenteric vein) | Four veins join into one larger vessel which passes through the liver through another capillary bed. Think much like the lung's capillary system. Then it dumps into the Inferior Vena Cava to return blood to circulation. | ## **Non-Reproductive Viscera** | Structure | Description | Function | |---|---|---| | Suprarenal/Adrenal Glands | Fatty, triangular masses of tissue atop each kidney | Secrete glucocorticoids & mineralocorticoids (steroid hormones). Most familiar hormones released are epinephrine (adrenaline) and norepinephrine which is commonly associated with fight or flight. Cortisol: a glucocorticoid hormone associated with stress which can signal glucose release for fight or flight so enough fuel is available for the body respond. Aldosterone: a mineralocorticoid responsible for balancing minerals in blood and, therefore, blood pressure. | | Kidneys | Bean-shaped organs | Filter blood, create urine, maintain blood solutes | | Ureters | Long thin tubes connecting the kidneys to the bladder | Urine transport | | Urinary Bladder | Stretchy organ which can look like a flattened balloon when empty | Holds urine between periods of micturating (urinating) | | Urethra: | Tube from bladder to external orifice | Passes urine to the outside environment while micturating (urinating) | | Prostatic Urethra (Male only) | Passes through the prostate | Transmits urine; semen formed here by combining secretions from epididymis, seminal vesicles, and prostate | | Membranous Urethra (Male only) | Connects urethra to external orifice | Passage of urine and semen | | Spongy/Penile Urethra (Male only) | Longest part of the male urethra | Conducts urine and semen | | External Urethral Orifice | Opening where urethra is in contact with external environment | Orifice where urine exits the body (in males, this is also where semen exits the body) | ## **Reproductive Viscera (Female)** | Structure | Description | Function | |---|---|---| | Ovary | Paired, lateral to uterus | Creates/secretes estrogen & progesterone, produce oocytes | | Fimbriae | Finger-like projections extending from each infundibulum | Moves oocytes into an infundibulum | | Uterine Tube (Fallopian Tube): | Paired, extend from uterus to ovaries, aka fallopian tubes or oviducts | Passageway for oocytes & sperm, site of fertilization | | Infundibulum of Uterine Tube | Paired, funnel-shaped ends of uterine tubes | Oocyte passageway | | Ampulla of Uterine Tube | Portion of fallopian tube; curves over ovary | Most common site of human fertilization (Fertilization happens in the Uterine tube but the section of the uterine tube where this happens is most commonly the ampulla) | | Isthmus of Uterine Tube | Small portion of fallopian tube towards top of uterus | Connects ampulla and infundibulum to the uterus | | Uterus: | Hollow, muscular organ posterior to urinary bladder; usually tilted anteriorly in adult | Site of fetal development, passageway for menstrual fluid, sperm, and fetus | | Cervix | Inferior, narrow portion of uterus that projects into vagina | Passageway for menstrual fluid, sperm, & fetus | | Vagina | Muscular, elastic tube that opens into external environment | Passageway for fluid (menstrual fluid exit or semen entry) and fetus |