cardiac

• Heart


  • Cone shape / inverted pyramid organ
  • Small, same size as a closed fist
  • Rests on the Diaphragm
• Functions of the heart

  • Generating blood pressure
  • Routing blood
  • Regulating blood supply
• Location of the heart

  • Located in the thoracic cavity between the lungs
  • Lies obliquely in the mediastinum
  • Base of the heart extends to the level of the 2nd ICS
  • Apex is located deep to the 5th ICS, ~ 7-9 cm to the left of the sternum, near the midclavicular line

  
• Base and Apex

  • 2/3 of the mass is located on the (L)
  • Base is broad portion, posterior, superior and pointing to the R
  • Apex is pointed end, anterior, inferior pointing towards the L

  
• Surfaces of the heart

  • Sternocostal (R atrium and R ventricle)
  • Diaphragmatic ((R) and (L) ventricles, inferior surface of the ® atrium)
  • Base ((L) atrium)
  • Apex ((L) ventricle)

  
• Borders of the heart

  • R border (R atrium)
  • L border ((L) atrium and (L) ventricle)
  • Lower border ((R) Ventricle and (R) Atrium)
  • Apex ((L) ventricle)

  
• Pericardium


  • Fibrous connective sac
  • 2 Layers:
  • Fibrous : outer, prevents the heart form over stretching, anchors the heart in the mediastinum Serous : innermost layer, has visceral and parietal layers

  
• Pericardial fluid


  Decreases friction, located between visceral and parietal serous pericardium, normal volume: 50 mL
• Heart wall layers

  • Epicardium (smooth outer surface, same as visceral pericardium)
  • Myocardium (cardiac muscle cells, contraction of the heart chambers)
  • Endocardium (inner surface of the heart chambers, allows blood to move easily)

  
• External anatomy of the heart

  • Auricles
  • Ventricles
  • Sulcus
  • Coronary sulcus
  • Anterior interventricular sulcus
  • Posterior interventricular sulcus

  
• External structures of the heart

  • Superior Vena cava
  • Inferior Vena cava
  • 4 pulmonary vein
  • Pulmonary trunk
  • 2 pulmonary artery
  • Aorta
• Valves of the heart

  • AV valves (inlet valves, prevent backflow into the atria during ventricular contraction, Tricuspid and Bicuspid/Mitral)
  • SL Valves (outlet valves, prevent backflow of blood from aorta and pulmo artery into the ventricles during ventricular relaxation, Pulmonic and Aortic)
• Blood flow through the Heart

  1. SVC/ IVC (deoxygenated)

  2. (R) Atrium

  3. Tricuspid valve

  4. (R) Ventricle

  5. Pulmonary arteries

  6. Lungs (oxygenated)

  7. Pulmonary veins

  8. (L) Atrium

  9. Mitral/ Bicuspid

  10. (L) Ventricle

  11. Aorta

  12. Systemic Circulation
• Blood Supply to the heart

  • (L) Coronary Artery (Anterior interventricular artery/LADA, Circumflex artery, (L) marginal artery)
  • (R) Coronary Artery ((R) Posterior interventricular artery, (R) Marginal Artery)
• Venous drain

  • Great cardiac vein
  • Middle cardiac vein
  • Small cardiac vein
  • Coronary sinus
• Conduction system of the Heart

  • SA node (dominant pace maker, located at SVC and R atrium)
  • AV node (located at Jxn of (R) atrium and (R) ventricle, slow conduction, slight delay before impulses are carried)
  • Bundle of HIS (located on the top of IV septum, transmits impulse to bundle branches)
  • Bundle branches (located either side of IV septum, L bundle = LV, R budle = RV)
  • Purkinje fibers (transmits electric throughout the ventricles)
• Branches of AORTA


  • Aortic Arch (L Common carotid, Brachiocephalic artery, L Subclavian artery)
  • Ascending aorta
  • Descending aorta
• Heart Sounds


  • S1 (Lub, closure of AV valves, longer, louder, lower)
  • S2 (Dub, closure of SL valves, shorter, not as loud as S1)
  • S3 (Ventricular gallop, rapid filling of ventricles, normal in children and last trimester of pregnancy, condition: CHF)
  • S4 (Atrial gallop, normal in athlete, conditions: CAD, Post MI, Post CABG, Aortic stenosis, Chronic HTN)
• Functions of the Peripheral Circulation

  • Carries blood
  • Exchanges nutrients, waste products and gases with tissues
  • Transports substances
  • Helps regulate blood pressure
  • Directs blood flow to tissues
• Blood Vessel Wall Layers

  • Tunica Intima (endothelium, basement membrane, connective tissue)
  • Tunica Media (smooth muscle cells, elastic and collagen fibers)
  • Tunica Adventitia (connective tissue)

  
• Arteries

  • Elastic Arteries (largest diameter and thickest walls, greater proportion of elastic tissue than smooth muscle tissue, elastic recoil)
  • Muscular arteries (thickness of the walls from the smooth muscles of the tunica media, vasoconstriction and vasodilation)
  • Small arteries (smaller diameter and thinner walls)
  • Arterioles (transport blood from small arteries to capillaries, control the amount of blood reaching the capillaries)

  
• Capillaries


  Has a thin wall which is consist of endothelium only, capillary bed, thoroughfare channels, precapillary sphincter
• Veins

  • Venules (transport blood from capillaries to small veins)
  • Small Veins (collect blood from venules and deliver it to medium-sized veins)
  • Medium-sized veins (deliver blood to the large veins)
  • Valves (allow Blood to flow towards the heart) - Predominant layer of vein: adventitia
• Abdominal Cavity


  The region of the trunk that lies between the diaphragm above and the inlet of the pelvis below

  
• Boundaries of the Abdominal Cavity

  • Superior boundary: Diaphragm
  • Inferior boundary: Pelvic inlet

  
• Abdominal Regions


  • RUQ
  • LUQ
  • RLQ
  • LLQ
  • R Hypocondriac region
  • R Lumbar region
  • R iliac region
  • Epigastric region
  • Umbilical region
  • Hypogastric region
  • (L) Hypocondriac region
  • (L) Lumbar region
  • (L) iliac region
• Abdominal Muscles

  • Pyramidalis
  • external abdominal oblique
  • internal abdominal oblique
  • Transversus abdominis muscles
  • quadratus lumborum
  • iliopsoas muscle group
• Inguinal Canal


  • Origin: Superolaterally at the deep inguinal ring
  • Path: Traverses the abdominal wall
  • Termination: Near the pubic tubercle at the superficial inguinal ring
  • Function in fetal life (males): Allows physiological descent of testes into the scrotum
  • Function in adult life (males): Conduit for spermatic cord and ilioinguinal nerve
  • Function in adult life (females): Passage for round ligament of uterus and ilioinguinal nerve

  
• Inguinal Canal

  • Weakest point of trunk wall, prone to herniations (inguinal hernia), especially in males due to testis descent
  • Roof: Formed by internal oblique and transversus abdominis muscles
  • Anterior Wall: Derived from aponeuroses of internal and external abdominal oblique muscles
  • Floor: Formed by inguinal and lacunar ligaments
  • Posterior Wall: Formed by transversalis fascia and conjoint tendon of abdominal internal oblique muscles

  
• Organs of the digestive system

  • Mouth
  • Pharynx
  • Esophagus
  • Stomach
  • Intestines
  • Teeth
  • Tongue
  • Salivary glands
  • Liver
  • Pancreas
  • Gallbladder
• Histology of alimentary canal

  • Mucosa (innermost, absorption)
  • Submucosa (connective tissue, secretory function)
  • Muscularis (inner circular smooth muscle, outer longitudinal smooth muscle, motility function)
  • Serosa (outermost, visceral peritoneum)

  
• Salivary Gland


  • Secrete saliva into the mouth (buccal cavity)
  • Saliva is 99.5% water and 0.5% solutes, contains immunoglobulin A to protect the mouth from bacteria, normal volume: 1,000 – 1,500 mL
• Salivary Gland Secretions

  • Serous secretion (salivary amylase/ PTYALIN, starch digesting enzyme)
  • Mucus Secretion (MUCIN, moisture to the food, bind the food together)
• Salivary Glands

  • Parotid (largest, anterior and inferior to the ears between skin and masseter)
  • Submandibular (under the base of tongue in the posterior part of the floor of the mouth)
  • Sublingual (superior to submandibular gland)
• Deciduous Teeth


  • 20 in number, 4 incisors in each jaw, 2 canines in each jaw, 4 molars in each jaw, first teeth to erupt: Lower central incisors = 6 mos, all deciduous teeth is lost at 6 to 12 years old
• Permanent Teeth

  • 32 Distributed over dental arches, 1 central incisor, 1 lateral incisor, 1 canine, 2 premolars, 3 molars
• Tongue


  Floor of the mouth, extrinsic muscle, for the movement of the tongue: side to side, in and out
• Serous secretion


  Secretion that is thin and watery
• Salivary amylase/PTYALIN


  Starch digesting enzyme
• Moisture to the food

  Binds the food together