Chapter 7

CARDIOVASCULAR SYSTEM


Systemic Circulation — EXTERNAL LOOP, Delivers oxygenated blood to all body cells/tissues and removes waste.

  •  Pulmonary Circulation — INTERNAL LOOP, Eliminates Sends blood to lungs for gas exchange.

  •  Heart Apex — Inferior, pointed end of the heart

  •  Myocardium — Thick, muscular middle layer of the heart.

  •  Epicardium — Outer layer that reduces friction.

  •  Endocardium — Inner lining of heart chambers.

  • How many chambers does the heart have? — 4

    • 2 Atrias in the Heart — Thin upper chambers receive blood returning to the heart through veins

    • 2 Ventricles in the Heart — Thick, muscular lower chambers receive blood from the atria above, then pump blood out of the heart through arteries

  • Right Atrium — Receives deoxygenated blood from vena cavae.

  •  Left Atrium — Receives oxygenated blood from pulmonary veins.

  • Right Ventricle — Pumps blood to lungs.

  • Left Ventricle — Pumps oxygenated blood to the body.

  • Septum — Wall separating right and left sides of heart.

  • LEFT Atrioventricular valve (AKA Bicuspid/Mitral Valve) — AV valve on left side.

  • RIGHT Atrioventricular valve (AKA Tricuspid Valve) — AV valve on right side.

  • Aortic Valve — Semilunar valve between the left ventricle and the aorta

  • Pulmonary Valve — Semilunar valve between the right ventricle and the aorta

  • Chordae Tendineae — Fibrous cords preventing AV valve inversion; anchor flaps of the valve

  • Papillary Muscles — Anchor chordae tendineae.

  • Coronary Arteries — Supply heart tissue with oxygen; blockage causes heart attack.

  • Fibrous Pericardium — Protective sac around heart.

  • Pericardial Cavity — Fluid-filled space reducing friction.

SKELETAL SYSTEM


Hematopoiesis — Blood cell formation in bone marrow.

  • Axial Skeleton — Head, neck, trunk, skull, Hyoid Bone, vertebral column, rib cage, sternum

  • Appendicular Skeleton — Limbs + girdles.

    • Connect Limbs to:

      • Pectoral - (Scapula & clavicle), upper limbs (arms)

      • Pelvic Girdle - (Coxal bones), lower limbs (legs)

  • Epiphysis — End of bone.

  • Diaphysis — Shaft of long bone.

  • Articular Cartilage — cartilage covering bone ends.

  • Periosteum — Tough outer membrane covering outside bone.

  • Medulla - Within Diaphysis, contains bone marrow and blood is supplied here

  • Medullary Cavity — Hollow space containing yellow marrow.

  • Endosteum - Lining of the Medullary Cavity (Epithelial)

  • Red Marrow - Produces blood cells

  • Yellow Marrow - Fat storage


  • Flat Bones - Protection (ex; sternum, ribs, skull bones)

  • Long Bones - Support weight; movement (ex; femur, tibia, fibula

  • humerus, radius, ulna)

  • Short Bones - Stability, movement (ex; carpals, tarsals)

  • Irregular Bones - Protects organs (ex; vertebrae, pelvis)

  • Sesamoid Boins - Reinforce tendons (ex; patella/kneecap)


  • Compact (AKA Cortical) Bone — Dense outer bone tissue, wall of diasphysis

  • Spongy (AKA Cancellous) Bone — Porous tissue in epiphyses containing red marrow.

  • Sharpey’s Fibers - finger-like projections that attach the periosteum to bone


  • Osteocytes — Mature bone cells in lacunae.

  • Lacunae — Chambers holding osteocytes.

  • Lamellae — Rings of bone matrix.

  • Haversian Canal — Central canal with blood vessels.

  • Canaliculi — Tiny canals connecting osteocytes.


  • Osteoblasts — Build bone.

  • Osteoclasts — Break down bone.


  • Fibrous Joint — Immovable joint (skull sutures).

  • Cartilaginous Joint — Slightly movable (vertebrae).

  • Synovial Joint — Freely movable (knee, elbow)



  • Ball-and-Socket Joint — Shoulder, hip.

  • Hinge Joint — Knee, elbow.

  • Pivot Joint — Lower arm, Ulna and radius.

  • Saddle Joint — Thumb.

  • Gliding Joint — Jaw, wrist, ankle.

  • Gomphosis — Tooth socket.


  • Cervical Vertebrae — C1–C7.

  • Thoracic Vertebrae — T1–T12.

  • Lumbar Vertebrae — L1–L5.

  • True Ribs — First 7 pairs.

  • False Ribs — Next 3 pairs.

  • Floating Ribs — Last 2 pairs.

  • Scapula — Shoulder blade.

  • Clavicle — Collarbone.

  • Radius — Forearm bone that aligns with thumb.

  • Ulna — Forearm bone aligning with pinky.

  • Carpals — 8 wrist bones.

  • Metacarpals — Hand bones.

  • Phalanges — Finger and toe bones.

  • Femur — Thigh bone.

  • Tibia — Large shin bone.

  • Fibula — Smaller shin bone.

  • Tarsals — Ankle bones.

  • Calcaneus — Heel bone.

  • Osteoporosis — Porous bone from increased osteoclast activity.

  • Rickets — Vitamin D deficiency causing weak bones.

  • Osteosarcoma — Bone cancer common in teens.

  • Scoliosis — Lateral spine curvature.

  • Kyphosis — Hunchback curve.

  • Lordosis — Swayback curve.

  • FOP — Soft tissues turn into bone.

RESPIRATORY SYSTEM

  • External Respiration — Gas exchange between lungs and blood (air → blood)

  • Internal Respiration — Gas exchange between blood and tissues (blood → tissues)

  • Cellular Respiration — Cells use Oxygen to make ATP.

  • Upper Respiratory Tract — Nose, nasal cavity, sinuses, pharynx.

  • Lower Respiratory Tract — Larynx, trachea, bronchi, lungs.

  • Nasal Cavity – hollow space behind the nose  

  • Nasal septum – divides the nose (bone)

  • Deviated septum – when the septum bends to one side, results in the nose being crooked.

  • Mucus Membrane - warms and moistens air, also traps particles (dust)

  • Nasal Conchae — Bones that divide the nasal cavity; Increase surface area, warm & filter air.

  • Paranasal Sinuses — Air spaces within skull bones that reduce weight ot skull

  • Pharynx — Space behind the oral cavity, between the nasal cavity and larynx

  • Larynx — Voice box; contains vocal cords, composed of muscles and cartilage at the top of trachea

  • Glottis - part of the larynx consisting of the vocal cords 

  • Epiglottis — Prevents food from entering airway.

  • Trachea — flexible cylinder with cartilage to give it stiffness and keep it from collapsing and leads to Bronchial Tree

  • Bronchi — Trachea → Primary Bronchi → Secondary Bronchi → Tertiary Bronchi  → Bronchioles

  • Bronchioles — Smaller branches with alveoli.

  • Alveoli — Air sacs for gas exchange via diffusion connected to circulatory system via capillaries

  • Lungs - Spongy tissue that sit within the pleural cavity


  • Diaphragm — Major breathing muscle, moves down, forcing air into airways

  • Relaxing the diaphragm - causes elastic recoil(exhalation)

  • Pneumothorax - collapsed lung, A hole in the pleural cavity can cause the lung to collapse

  • Pleural Cavity — Fluid-filled space around lungs.

  • Tidal Volume — Air in a normal breath/1 cycle

  • Vital Capacity — Max air that can be exhaled/inhaled.

  • Respiratory Rate — 12–18 breaths/min.

  • Respirometer - Device used to measure the rate of respiration measuring its rate of exchange of oxygen and/or carbon dioxide.

  •  Respiratory Center — groups of neurons in the brain that control inspiration and expiration in the medulla and the pons

  • Spirometry - measures the volume of air moving in and out of the lungs

  • Resting Tidal Volume - amt. Of air that enters the lungs during 1 cycle

  • Reserve Volumes - amt. of air that can be inhaled or exhaled after normal breath

  •  Hyperventilation — Low CO₂ from rapid breathing.

  •  Hypoxia — Low oxygen at tissue level.

  •  Cyanosis — Blue skin from hypoxia.

  •  Asphyxia — Inability to breathe normally (ex: choking).

  •  COPD — Blocked airflow; usually smoking-related.

  •  Bronchitis — Inflammation of bronchi.

  •  Asthma — Inflamed bronchioles with mucus.

  • Sleep Apnea — Pauses in breathing during sleep.

  •  Pulmonary Embolism — Blood clot in lungs.

  •  Pneumothorax — Collapsed lung.

Cardiac Cycle & Heart Actions


Cardiac Cycle → One complete heartbeat.

  • Systole → Contraction of a heart chamber.

  • Diastole → Relaxation of a heart chamber.

  • Aortic Valve During Ventricular Systole → Opens.

  • Aortic Valve During Diastole → Closes.

Blood Pressure

  • Blood Pressure → Force of blood against arterial walls.

  • Systolic Pressure → Maximum pressure during ventricular contraction.

  • Diastolic Pressure → Pressure when ventricles relax.

  • Normal Adult Blood Pressure → 120/80 mmHg.

  • Sphygmomanometer → Instrument used to measure blood pressure.

Factors Affecting Blood Pressure

  • Cardiac Output → Amount of blood pumped per minute.

  • Blood Volume → Total amount of blood in the body (avg 5 liters).

  • Blood Viscosity → Thickness of blood.

  • Peripheral Resistance → Resistance of arteries to blood flow.

Heart Sounds & Pulse

  • “Lub Dub” → Sounds from closing/opening of heart valves.

  • Stethoscope → Device used to listen to heart sounds.

  • Normal Adult Heart Rate → 60–100 bpm.

  • Pulse Points → Places where arteries lie close to the skin (carotid, radial, brachial).

ECG / EKG

  • ECG (Electrocardiogram) → Recording of electrical events of the cardiac cycle.

  • P Wave → Atrial depolarization (atrial systole).

  • QRS Complex → Ventricular depolarization (ventricular systole).

  • T Wave → Ventricular repolarization.

  • Tachycardia → Fast heart rate.

  • Bradycardia → Slow heart rate.

  • Arrhythmia → Irregular heartbeat.



Cardiac Conduction System

  • S-A Node (Sinoatrial Node) → Pacemaker of heart; 60–100 bpm.

  • Junctional Fibers → Transmit impulses from atria to ventricles.

  • A-V Node (Atrioventricular Node) → Delays impulse so atria empty before ventricles contract; backup pacemaker (40–60 bpm).

  • A-V Bundle (Bundle of His) → Carries impulse toward apex of heart.

  • Purkinje Fibers → Conduct impulses rapidly to ventricles → contraction.

Blood Vessels

  • Arteries → Strong, elastic vessels carrying blood away from the heart.

  • Arterioles → Smallest arteries leading to capillaries.

  • Veins → Vessels carrying blood toward the heart; thinner walls; contain valves.

  • Venules → Smallest veins connecting capillaries to veins.

  • Capillaries → Site of gas & nutrient exchange with tissues.

Blood Flow Control

  • Precapillary Sphincters → Muscles controlling blood flow into capillaries.

  • Vasoconstriction → Narrowing of blood vessels.

  • Vasodilation → Widening of blood vessels.

  • Venous Blood Return Helpers → Skeletal muscle pump, diaphragm contraction, venous valves.

Major Vessels

  • Aorta → Largest artery; leaves left ventricle.

  • Pulmonary Trunk → Splits to pulmonary arteries; carries blood to lungs.

  • Pulmonary Veins → Return blood from lungs to left atrium.

  • Superior & Inferior Vena Cava → Return blood from body to right atrium.

  • Coronary Arteries → Supply blood to the heart muscle.

  •  Brachiocephalic Artery → Branches into right subclavian and right common carotid.

  • Left Common Carotid → Supplies blood to head.

  • Left Subclavian Artery → Supplies blood to left arm.

Heart/Circulatory Disorders

  • SADS → Sudden Arrhythmia Death Syndrome.

  • Defibrillator → Device that shocks the heart to restore normal rhythm.

  • CPR → Cardiopulmonary resuscitation.

  • Heart Murmur → Unusual sound during heartbeat.

  • Mitral Valve Prolapse (MVP) → Valve shifts out of place; clicking sound.

  • Regurgitation → Backflow of blood due to faulty valve.

  • Valve Replacement → Replacement with biological or mechanical valve.

  • TAVR → Minimally invasive aortic valve replacement procedure.

  • Myocardial Infarction (Heart Attack) → Blockage of coronary artery.

  • Angioplasty → Balloon widens artery; sometimes includes stent.

  • Atherosclerosis → Plaque buildup in arteries.

  • Hypertension → High blood pressure.

  • Aneurysm → Balloon-like bulge in vessel wall.

  •  Stroke → Blood flow cut off to brain.

  • Aortic Stenosis → Narrowed aorta or valve.

  • Septal Defect → Hole between left and right chambers.

Components of Blood

  • Blood Volume → 4–6 liters; 8% of body mass.

  • Plasma → 55% of blood; 90% water, 10% solutes.

  • Albumins → Plasma protein group.

  • Globulins → Plasma protein group.

  • Fibrinogen → Plasma protein for clotting.

Blood Cells

  • Red Blood Cells (Erythrocytes) → Most numerous; carry oxygen; contain hemoglobin; biconcave shape.

  •  Hemoglobin → Iron-containing protein that binds oxygen.

  • White Blood Cells (Leukocytes) → Fight disease; fewer than RBCs; formed in bone marrow.

  • Platelets → Enable clotting.

  • Steps of Clotting → 1. Vessel break → 2. Platelet clumping → 3. Clot formation.