Week 10 Content Flashcards
The Heart
Muscular double pump
- Cardiac muscle
Circulates blood
Delivers oxygen and nutrients
Removes carbon dioxide and waste
Circuits of the Heart
- Pulmonary circuit
- Systemic circuit
Pulmonary Circuit
Transports blood between the heart and lungs
Right side receives oxygen-poor blood
- Sends blood to lungs via pulmonary arteries
Blood gains O2, releases CO2
Systemic Circuit
Delivers oxygen-rich blood to the body
Left side of the heart receives blood from lungs
- Pumped to organs via the aorta
Supplies tissues with O2 and nutrients
Chambers of the Heart - Atria
4 Chambers: Atria and Ventricles
Atria (Superior)
- Right Atrium: Receives blood from the systemic circuit
- Left Atrium: Receives blood from the pulmonary circuit
Ventricles (Inferior)
Right Ventricle: Pumps blood to lungs (pulmonary circuit)
Left Ventricle: Pumps blood to body (systemic circuit), thicker walls
Pulmonary and Systemic Circuit Diagram
Heart Location and Orientation
Thorax, between lungs
Largest organ in the mediastinum
- 250-350 grams
Apex points left of midline
Base forms the broad posterior surface
Superior Corners
Right
- 3rd rib costal cartilage
- Right atrium upper boundary
Left
- 2nd rib costal cartilage
- Left atrium upper boundary
Heart Position Diagram
Four Corners of the Heart
- Superior right
- Inferior right
- Superior left
- Inferior left
Inferior Corners
Right
- 6th rib costal cartilage
- Right ventricle lower boundary
Left
- 5th intercostal space, midclavicular line
- Left ventricle lower boundary
Heart Covering - Pericardium
Protective sac encloses the heart
- Limits movement
- Reduces friction
- Fibrous pericardium
- Serous pericardium
Fibrous Pericardium
Strong outer layer
- Dense connective tissue
Protects the heart
- Prevents overfilling
Anchors heart to the diaphragm and sternum
Serous Pericardium
Thin, double-layered membrane
1. Parietal Layer
- Lines fibrous pericardium
2. Visceral Layer (Epicardium)
- Covers heart
Pericardial Cavity: Fluid-filled space between layers
Layers of the Heart Wall
- Epicardium
- Outer layer, protects heart, contains vessels, nerves, and far - Myocardium
- Middle layer, heart contractions - Endocardium
- Inner layer lining walls, reduces friction
Cardiac Muscle Tissue
Myocardium consists of striated cardiac muscle
- 1-2 nuclei per cell, joined at intercalated discs
Generates force to pump blood
Surrounded by endomysium
Septae
Interventricular Septum: Separates ventricles, prevents blood mixing
Interatrial Septum: Separates atria, maintains distinct blood flow
Right Atrium
Received deoxygenated blood from the body, pumped into the right ventricle
Superior Vena Cava (Upper body)
Inferior Vena Cava (Lower body)
Coronary Sinus (Heart muscle)
Internal Right Atrium Structures
- Pectinate muscles
- Crista terminalis
- Fossa ovalis
Pectinate Muscles
Ridges inside right atrium
Enhance contraction force
Structural support
Increase blood flow
Crista Terminalis
Ridge in right atrium separates pectinate muscle from atrial wall
Landmark to locate veins entering the right atrium
Right Ventricle
Receives blood from the right atrium via the atrioventricular valve (tricuspid valve)
Pumps blood into the pulmonary trunk, to lungs
Fossa Ovalis
Depression in interatrial septum
Remnant of foramen ovale
Allowed blood to bypass fetal lungs
Internal Right Ventricle Structures
- Trabeculae Carneae
- Papillary Muscles
- Chordae Tendineae
- Pulmonary Semilunar Valve
Trabeculae Carneae
Irregular cardiac muscle ridges, spongy
Line ventricle walls
Strengthen and assist in contraction
- ie; Moderator band
Papillary Muscles
Cone-shaped muscle projections in ventricle wall
Attach to chordae tendineae
Contract to prevent tricuspid valve prolapse
Assist valve closure
Control blood flow
Chordae Tendinea
Heartstrings
- Tendon-like cords, connect papillary muscles to valve cusps
Prevent valve prolapse
- Aid closure, prevent backflow
Diagram of Heart with Chordae Tendinea
Left Atrium
Posterior Surface
Receives oxygen-rich blood from lungs through pulmonary veins
Contracts to push blood into the left ventricle
Left Ventricle
Forms apex
Pumps oxygen-rich blood into the systemic circuit
Same internal wall structures as the right ventricle
- Trabeculae carneae
- Papillary muscles
- Chordae tendineae
Detailed Anterior (Front) Heart Diagram
Detailed Inferior (Bottom) Heart Diagram
Valves Overview
Ensure one-way blood flow through the heart
- Endocardium, reinforced with connective tissue
Types of Valves
- Atrioventricular (AV) Valves
- Between atria and ventricles, prevent backflow - Semilunar Valves
- Between ventricles and major arteries
Atrioventricular (AV) Valves
Right AV Valve: Tricuspid valve (3 cusps)
Left AV Valve: Bicuspid (mitral) valve (2 cusps)
Right Atrioventricular (Tricuspid) Valve
Opening of right atrium and right ventricle
- Anterior, posterior, septal cusp
Left Atrioventricular (Bicuspid) Valve
Left ventricle opens into the left AV valve (mitral valve)
Valve flaps anchored into capillary muscle by chordae tendineae
Anterior and posterior cusp
Semilunar Valves
Prevent backflow into ventricles during relaxation
Pulmonary Valve
- Between right ventricle and pulmonary trunk
Aortic Valve
- Between left ventricle and aorta
Frontal Section of Heart Diagram
Cardiac Skeleton Functions
Supports heart valves
- Prevents valve overdilation
Insertion for cardiac muscle fibers
Limit spread of electrical impulses for coordinated contractions
Heart Valve Diagram
Functions of AV Valves (Open)
Functions of AV Valves (Closed)
Functions of Semilunar Valves (Open)
Functions of Semilunar Valves (Closed)
Heartbeat
Valves closing during the cardiac cycle
AV Valves: Ventricular contraction (systole)
Semilunar Valves: Ventricular relaxation (diastole)
Blood Pressure
Systolic Phase: Heart contracts, blood pressure rises, blood exits
Diastolic Phase: Heart relaxes, blood pressure falls, heart fills
Normal Range: 120/80 mmHG (systolic/diastolic)
How the Heart Regulates Blood Pressure
Cardiac output
Peripheral resistance
Elasticity of arteries
Abnormal Blood Pressure
- Hypertension (High BP): >130/80 mmHG
- Hypotension (Low BP): <90/60 mmHG
Listening to the Heart
Pathway of Blood Through the Heart and Lungs
Oxygen-poor blood enters the heart
- Superior and inferior venae cavae
- Right atrium
- Right atrium contracts
- Blood pushed through tricuspid valve to the right ventricle
- Right ventricle contacts
- Blood pushed through pulmonary semilunar valve
Lungs
- Pulmonary trunk
- Pulmonary arteries
- Lungs
- Blood picks up O2, and releases CO2 in lungs
Oxygen-rich blood returns to the heart
- Pulmonary veins
- Left atrium
- Left atrium contracts
- Blood pushed through mitral valve into left ventricle
- Left ventricle contracts
- Blood pushed through aortic semilunar valve into aorta
- Blood delivered to systemic circuit
Important Features of Circulation
Simultaneous Contraction
- Atria contract together
- Ventricles contract together
One-way flow
Cyclic process
Structure and Function of Heart Wall
Intrinsic Properties of Cardiac Muscle
Automaticity: Generates and conducts its own electrical impulses
Triggers and maintains rhythmic contractions
Sinoatrial (SA Node)
Pacemaker
- Sets contraction time
- 60-100 beats per min
Superior wall of right atrium, near superior vena cava
Atrioventricular Node (AV Node)
Interatrial septum
Transmits impulse from AV node to bundle branches
Only electrical connection between atria and ventricles
Atrioventricular (AV) Bundle
Bundle of His
- Intraventricular septum
Connects AV node to ventricles
Conducts impulses to ventricles
Bundle Branches
Split from AV bundle
Travel down the left and right sides of the septum
Conduct impulses to ventricles
- Left anterior fascicle
- Left posterior fascicle
- Right bundle branch
Purkinje Fibers
In ventricle walls
Rapidly transmit impulses to ventricular muscle cells
- Synchronized contraction
Efficient blood ejection into pulmonary artery and aorta
Simplified Flow of Electrical Signals
SA Node
- Internodal pathway
- AV node
- AV bundle (bundle of His)
- Bundle branches
- Purkinje fibers
Extrinsic Neural Control
Modifies heart’s rhythm
Parasympathetic fibers, sympathetic fibers, and visceral sensory fibers
Nerves pass through the cardiac plexus
Coronary Arteries
Deliver blood to heart walls and tissues
From the base of the aorta, within the coronary sulcus
1. Right coronary artery
2. Left coronary artery
Left Coronary Artery (LCA)
Supplies blood to the left side of the heart
1. Left anterior descending artery (LAD)
- Anterior heart and intraventricular septum (‘widowmaker’)
2. Circumflex artery
- Left artium and left ventricle
Right Coronary Artery (RCA)
Supplies blood to the right side of the heart
1. Marginal artery
- Anterior heart and intraventricular septum
2. Posterior descending artery (PDA)
- Intraventricular septum and right ventricle
Coronary Arteries in the Heart Diagram
Cardiac Veins
Carry deoxygenated blood from the heart wall to the right atrium
- In the sulci on the heart surface
- Coronary sinus
- Tributaries of the coronary sinus
Coronary Sinus
Posterior coronary sulcus
- Returns the majority of venous blood from the heart to the right atrium
Tributaries of the Coronary Sinus
- Great cardiac vein
- Anterior heart, along the left anterior descending artery - Middle cardiac vein
- Posterior heart, along the posterior interventricular artery - Small cardiac vein
- Right atrium and ventricle, along the right coronary artery
Coronary Artery Disease
Atherosclerosis: Buildup of fatty deposits in arteries
Angina Pectoris: Restricted blood flow, chest pain
Myocardial Infarction: Blocked coronary artery, tissue death
Silent Ischemia: Sudden reduced blood flow
Pericarditis
Inflammation of the pericardium
Chest pain and fluid buildup (pericardial effusion) impair function
Heart Failure
Progressive weakening, unable to meet oxygen demands
Congestive heart failure: Heart enlarges, pumping efficiency declines
Pulmonary arterial hypertension: Right ventricle enlargement and failure
Disorders of the Conduction System
Arrhythmias: Variation from the normal rhythm
Can impact the atria and/or ventricles
Medication or defibrillation to achieve sinus rhythm
Ventricular Fibrillation (Vfib)
Rapid, chaotic electrical impulses in ventricles
Disrupt contraction, impair blood pumping
Often cause cardiac arrest, treated with defibrillation
Atrial Fibrillation (Afib)
Impulses circle within the atrial myocardium
Irregular signals reach the AV node
Clots form, increase stroke risk
Treated with medication or electrical cardioversion
Age-Related Heart Changes
Thickened, stiff muscle and valve cusps
Increased fat deposition and plaques
Cardiomyocyte hypertrophy
Reduced cardiac reserve
Altered electrical conduction
Decreased efficiency of coronary arteries
Heart Health
Avoid tobacco
Regular exercise strengthens heart muscle
Aerobic exercise clears fatty deposits in the coronary arteries
Heart-healthy diet
Blood Vessels
Network of hollow tubes
- Transport blood
- Deliver oxygen, hormones, and nutrients to tissues
- Remove carbon dioxide and waste products
Structure of Blood Vessel Walls
3 layers and a central lumen
1. Tunica intima
2. Tunica media
3. Tunica externa
Lumen
Hollow center of vessel
Size varies depending on vessel type
Vein and Artery Diagram
Types of Blood Vessels
- Arteries: Carry blood from the heart, branch into arterioles
- Capillaries: Exchange oxygen, nutrients, and waste
- Veins: Return blood to the heart, formed by merging venules
Blood Vessel Flow Path
Heart - Arteries - Arterioles - Capillaries - Venules - Veins - Heart
Capillaries
Smallest vessels (8-10um)
Allow red blood cells to pass through
Exchange O2/CO2, nutrients, hormones, waste
Capillary Beds
Capillary network supplying tissues
Precapillary sphincters control flow
Limited supply in tendons and ligaments
No supply in epithelia or cartilage
Venous Vessels
Return blood from capillaries back to the heart
Lower internal pressure than arteries
Venules (8-100um) merge to form larger veins
Veins
Carry 65% of the body’s blood
Larger lumens, thinner walls, less elastic tissue
Thicker tunica externa and valves
Mechanisms for Low Venous Pressure
Valves in limb veins prevent backflow
Skeletal muscle contractions press against veins, push blood forward
Vascular Anastomoses
Blood vessels form networks
Arteries create collateral channels (anastomoses) to supply organs
Veins anastomose more than arteries
Pulmonary Circuit
Closed loop, starts and ends at the heart
- Gas exchange in the lungs
- Pulmonary trunk
- Pulmonary veins
- Pulmonary vessels
Features of Pulmonary Circulation
Pulmonary Trunk: Exits right ventricle, splits into right and left pulmonary arteries
Pulmonary Veins: 4 veins return oxygenated blood to the left atrium
Thinner walls and lower pressure
Systemic Circulation
Systemic arteries carry oxygen-rich blood from the heart
Aorta: Largest artery
Originates from the left ventricle, branches to supply the body
Systemic Circulation Diagram
Pulse Points
Arteries close to the skin
- Used to assess heart rate and blood flow
- Head and neck
- Upper limb
- Lower limb
Pulse Points - Head and Neck
Superficial Temporal Artery: Lateral cranium, temporal region
Facial Artery: Below madible, near mouth angle
Common Carotid Artery: Lateral neck, next to the trachea
Pulse Points - Upper Limb
Brachial Artery: Medial to biceps tendon in the antecubital fossa
Radial Artery: Lateral wrist, near base of thumb
Pulse Points - Lower Limb
Femoral Artery: Inguinal region, below inguinal ligament
Popliteal Artery: Posterior knee, popliteal fossa
Posterior Tibial Artery: Medial ankle, behind medial malleolus
Dorsalis Pedis Artery: Dorsum of foot
The Aorta
- Ascending aorta
- Aortic arch
- Descending aorta
Ascending Aorta
Arises from the left ventricle
Right coronary artery: Right atrium, ventricle, part of conducting system
Left coronary artery: Supplies left side of the heart
- Left anterior descending artery
- Circumflex artery
Descending Aorta - Thoracic
T5-T12
Intercostal arteries: Intercostals and thoracic wall
Bronchial arteries: Lung tissue (except alveoli)
Esophageal arteries: Esophagus
Aortic Arch
Behind the manubrium
Brachiocephalic trunk
- Right common carotid artery: Right side of the head/neck
- Right subclavian artery: Right upper limb and thorax
Left common carotid artery: Left side of the head/neck
Left subclavian artery: Left upper limb and thorax
Descending Aorta - Abdominal
Ends at L4
Celiac artery: Stomach, liver, spleen, upper duodenum
Superior mesenteric artery (SMA): Small and part of large intestine
Renal arteries: Kidneys
Inferior mesenteric arteries: Distal large intestine, rectum
Common iliac arteries: Pelvis, lower limbs
Full Heart Diagram
Arteries of the Head and Neck
- Common carotid arteries
- Subclavian arteries
a) Vertebral arteries
b) Thyrocervical trunk
c) Costocervical trunk
Common Carotid Arteries
Anterior triangle of neck
- External carotid artery
- Internal carotid artery
External Common Corotid Artery Branches
- Superior thyroid artery
- Ascending pharyngeal
- Lingual artery
- Facial artery
- Occipital artery
- Posterior auricular artery
- Maxillary artery
- Superficial temporal artery
Mnemonic: Some Anatomists Like Freaking Out Poor Med Students
Branches Supplying the Face and Neck
Superior thyroid artery: Thyroid, larynx, trachea, and neck muscles
Ascending pharyngeal: Pharynx, soft palate, tonsils, nasopharynx, middle ear
Lingual Artery: Tongue, floor of mouth, soft palate
Facial Artery: Facial skin, muscles, lips, eyes, nose, soft palate, and tonsils
Branches Supplying the Scalp
Occipital artery: Posterior scalp, neck, and occipital region
Posterior auricular artery: Ears, posterior scalp
Superficial temporal artery: Temporal scalp, frontal region, lateral face
Branches Supplying the Jaw
Maxillary artery: Largest terminal branch
- Mastication muscles, teeth, palate, nasal cavity, and parts of ear
Internal Common Carotid Artery Branches
- Ophthalmic artery
- Anterior cerebral artery
- Anterior communicating artery
- Middle cerebral artery
Mnemonic: Only Angry Ants March
Branches Supplying the Eyes
Ophthalmic artery: Retina, optic nerve, extraocular muscles, eye socket structures
Branches Supplying the Cerebrum
Anterior cerebral artery: Medial and superior frontal lobe, superior parietal lobes
Anterior communicating artery: Connects left and right anterior cerebral arteries
Middle cerebral artery: Motor cortex, somatosensory cortex, Broca’s area, and Wernicke’s area
Circle of Willis
Network of arteries, ventral brain
- Anterior communicating artery
- Internal carotid arteries
- Posterior cerebral arteries
- Posterior communicating arteries
Collateral circulation
Arteries of the Head and Neck
Subclavian Arteries
Right subclavian
- From brachiocephalic trunk
- Supplies right upper limb, neck, and part of the brain
Left subclavian
- Third branch of aortic arch
- Supplies left upper limbs, neck, and part of the brain
Vertebral Arteries
Originate from subclavian arteries
Supply posterior brain
Enter skull through the foramen magnum
Join to form the basilar artery
Basilar Artery
Union of vertebral arteries
- Supplies brainstem, cerebellum, and posterior brain
Divides into posterior cerebral arteries
- Supply occipital lobe and inferior temporal lobes
Posterior Communicating Artery
Connect posterior cerebral arteries to middle cerebral arteries
Part of the Circle of Willis
Alternative route for blood to brain
Thyrocervical Trunks
Branch of subclavian artery
- Inferior thyroid artery: Thyroid, part of neck
- Transverse cervical artery: Neck muscles and skin
- Suprascapular artery: Shoulder and scapula
Costocervical Trunk
Branch of subclavian artery
- Superior intercostal artery: First 2 intercostals
- Deep cervical artery: Deep muscles of back
Arteries of the Thorax
- Internal thoracic arteries: Intercostals, skin of anterior thoracic region
- Anterior intercostal arteries: Intercostals, skin of anterior thoracic region
- Posterior intercostal arteries: 9 pairs, posterior intercostals, skin, and pleura
Arteries of the Upper Limbs
- Axillary artery
- Brachial artery
Branches of the Axillary Artery
- Superior thoracic
- Thoracoacromial artery
- Lateral thoracic artery
- Subscapular artery
- Anterior circumflex humeral artery
- Posterior circumflex humeral artery
Mnemonic: Screw The Lawyer, Save A Patient
Branches of the Axillary Artery (First 3)
- Superior thoracic: Upper chest, part of thorax
- Thoracoacromial artery: Shoulder, pectoral region, chest, acromion
- Lateral thoracic artery: Chest muscles, breast tissue
Branches of the Axillary Artery
- Subscapular artery: Shoulder muscles, scapula
- Anterior circumflex humeral artery: Shoulder joint, upper arm muscles (anterior)
- Posterior circumflex humeral artery: Shoulder joint, upper arm muscles (posterior)
Brachial Artery
Lower border of teres major, anterior arm
- Deep brachial artery: Posterior arm muscles
- Musculocutaneous artery: Anterior arm muscles
Branches of the Brachial Artery
- Radial artery: Near elbow, along radius, supplies lateral forearm, wrist, hand, and fingers
- Ulnar artery: Near elbow, along ulna, supplies medial forearm, wrist, hand, and fingers
Branches of the Radial Artery
- Superficial palmar branch: Palmar arch of the hand
- Dorsal carpal branch: Posterior wrist and hand
- Digital arteries: Thumb and index finger
Branches of the Ulnar Artery
- Common interosseous artery: Forearm muscles
- Anterior and posterior interosseous arteries - Palmar branches: Superficial and deep palmar arch of hand
- Digital arteries: Digits 3-5
Arteries of the Abdominal Aorta
- Celiac trunk
- Superior mesenteric artery
- Inferior mesenteric artery
- Inferior phrenic arteries
- Suprarenal arteries
- Renal arteries
- Gonadral arteries
- Lumbar arteries
- Common iliac arteries
- Median sacral arteries
Mnemonic: Curry Soup Is Incredibly Spicy, Really Good Leftovers Cooker Monthly
Unpaired Branches
Celiac trunk: Stomach, liver, spleen, pancreas, part of esophagus
Superior mesenteric artery: Small and part of large intestine
Inferior mesenteric artery: Distal large intestine
Paired Branches
Inferior phrenic arteries: Inferior diaphragm
Suprarenal arteries: Adrenal glands
Renal arteries: Kidneys
Gonadal arteries: Testes and ovaries
Lumbar arteries: Back muscles, fascia, vertebrae, intervertebral discs
Terminal Branches
Common iliac arteries: Pelvis and lower limbs
Median sacral arteries: Sacrum and coccyx
Direct Major Branches of the Celiac Trunk
- Common hepatic artery: Liver, gallbladder, stomach, proximal duodenum, part of pancreas
- Left gastric artery: Lesser curvature of stomach, lower esophagus
- Splenic artery: Spleen, part of pancreas, stomach
Branches of Common Hepatic Artery
Hepatic artery proper: Liver, gallbladder, stomach
Gastroduodenal artery: Proximal duodenum, head of pancreas, greater curvature of stomach
Right gastric artery: Lesser curvature of stomach
Midline Branches of Digestive Tract
- Superior Mesenteric Artery
- Middle colic artery
- Intestinal arteries
- Right colic artery
- Ileocolic artery - Inferior Mesenteric Artery
- Left colic artery
- Sigmoidal arteries
- Superior rectal artery
Branches of Superior Mesenteric Artery
Middle colic artery: Proximal 2/3 transverse colon
Right colic artery: Ascending colon
Intestinal arteries: Jejunum and ileum
Ileocolic artery: Termina ileum, cecum, appendix, and proximal ascending colon
Branches of Inferior Mesenteric Artery
Left colic artery: Distal 1/3 of transverse colon and descending colon
Sigmoidal arteries: Sigmoid colon
Superior rectal artery: Proximal rectum
Superior and Inferior Mesenteric Arteries Diagram
Arteries of the Pelvis
Common Iliac Artery
1. Internal iliac arteries: Pelvic organs, pelvic wall, gluteal region
2. External iliac artery: Lower abdominal wall, inguinal region
Main Branches of the Internal Iliac Arteries
- Superior gluteal artery: Gluteal muscles, hip joint
- Inferior gluteal artery: Gluteus maximus, hamstrings, part of hip
- Obturator artery: Obturator externus, thigh adductors, part of hip
- Internal pudendal artery: External genitalia, perineum, anal canal
Additional Branches of Internal Iliac Arteries
Uterine artery: Uterus and cervix
Vaginal artery: Vagina, pelvic diaphragm, part of rectum
Vesical arteries: Urinary bladder
Middle rectal artery: Rectum
Arteries of the Thigh and Knee
- Femoral artery: Main artery of thigh
- Deep artery of thigh: Main blood supply to thigh
- Obturator artery: Medial thigh, hip, and adductors
- Popliteal artery: Knee
Branches from Deep Artery of Thigh
Lateral circumflex femoral artery: Later thigh and hip
Medial circumflex femoral artery: Medial thigh and hip
Descending branch of lateral circumflex femoral artery: Knee joint
Branches of Popliteal Artery
Anterior tibial artery: Anterior leg, dorsum of foot
Posterior tibial artery: Posterior leg, sole of foot
Genicular arteries: Group of arteries, supply knee joint
Branch of Posterior Tibial Artery
Fibular artery: Deep, parallel to fibula, lateral leg
Tibial Artery Diagram
Dorsal Arteries of the Foot
Dorsalis pedis artery: Continuation of anterior tibial artery, contributes to plantar arch
Arcuate artery: Branch of dorsal pedis artery
Dorsal metatarsal arteries: Branch of arcuate artery
Dorsal digital arteries: Branch of dorsal metatarsal arteries
Plantar of the Foot
Lateral plantar artery: Lateral sole, deep plantar arch
Medial plantar artery: Medial sole, skin, muscles, and hallux
Plantar arch: Branches into digital arteries
Diagram of Leg Arteries
Vein Features
Carry deoxygenated blood to the heart
- Except pulmonary veins
Thin walls, large lumen
Valves prevent backflow
Main Systemic Veins
- Superior vena cava
- Inferior vena cava
- Coronary sinus
Systemic Veins
Deep veins run near arteries, large diameter
Superficial veins lie under the skin
Networks of interconnected veins are called venous plexuses
Special Venous Drainage Patterns
- Dural venous sinuses: Drain blood from the brain into internal jugular veins
- Hepatic portal system: Directs blood from the digestive tract to the liver
Venae Cavae and Tributaries
Largest veins
Superior vena cava (SVC): Drains blood above the diaphragm
Inferior vena cava (IVC): Drains blood below the diaphragm
Both empty into the right atrium
Tributaries: Small veins that flow into larger ones
Body Veins Diagram
Dural Venous Sinuses
Specialized venous channels in dura mater
Drain blood from the brain into internal jugular veins
- Superior and inferior sagittal sinuses
- Straight sinus
- Transverse sinuses
- Sigmoid sinus
Sagittal Sinuses
Superior sagittal sinus: Midline, drains cerebral veins and cerebrospinal fluid (CSF)
Inferior sagittal sinus: Along lower falx cerebri, joins straight sinus
Other Key Venous Sinuses
Straight sinus: Formed by inferior sagittal sinus and great cerebral vein, drains into confluence of sinuses
Transversen sinuses: Horizontal from confluence, drains into the sigmoid sinuses
Sigmoid sinus: S-shaped, drains into the internal jugular vein
Cavernous Sinus
Base of brain near sphenoid bone
Receives blood from…
- Ophthalmic veins (Drains orbit)
- Cerebral veins (Drains brain)
- Facial veins (Drains superficial face)
Confluence of Sinuses
At internal occipital protuberance in posterior head
Point where multiple sinuses converge
- Superior sagittal sinus
- Straight sinus
- Occipital sinus
- Transverse sinuses
Veins of the Head
Superficial temporal vein: Drains scalp/lateral head to external jugular vein
Occipital vein: Drains back of scalp/neck via external jugular vein
Posterior auricular vein: Drains scalp/behind ear to external jugular vein
Veins of the Neck and Chest
Vertebral vein: Drains cervical vertebrae, spinal cord, and neck muscles
Superior and middle thyroid veins: Drains thyroid gland
Brachiocephalic vein: Collects from the head, neck, upper limb, and chest
Subclavian vein: Drains upper limb and chest wall
Jugular Veins
Internal jugular veins: Drains brain, deep head and neck
External jugular veins: Drains scalp, superficial head and neck to subclavian vein
Veins of the Thorax
Azygos vein: Drains thoracic wall and right posterior abdomen into SVC
Hemiazygos vein: Drains lower left thoracic wall into azygous vein
Accessory hemiazygos vein: Drains upper left thoracic wall into azygous vein
Veins of the Upper Limbs
Deep veins: Run alongside arteries
- ie; Radial, ulnar, and brachial veins
Superficial veins:
1. Cephalic vein
2. Basilic vein
3. Median cubital vein
4. Median vein of the forearm
Key Superficial Veins
Cephalic vein: Lateral arm
Basilic vein: Medial arm
Median cubital vein: Connects cephalic and basilic veins at elbow
Median vein of the forearm: Drains forearm
Veins of the Upper Limbs
Axillary vein: Union of brachial and basilic veins, drains arm, axilla, and lateral thoracic wall into subclavian vein
Deep palmar venous arch: Drains palm into radial and ulnar veins
Superficial palmar venous arch: Drains skin of palm into cephalic and basilic veins
Digital veins: Drains digits into palmar venous arches
Tributaries of the Inferior Vena Cava
Collects deoxygenated blood to return to the heart
Along right lumbar vertebrae
Primary venous return from abdomen, pelvis, and lower body
Major Tributaries from the Abdomen
Hepatic veins: Drain liver
Renal veins: Drain kidneys
Right and left suprarenal veins: Drain adrenal glands
Inferior phrenic vein: Drain diaphragm
Tributaries from the Pelvis and Lower Body
External iliac vein: Drains lower limbs
Internal iliac vein: Drain pelvis
Common iliac vein: Union of external and internal iliac veins, confluence to form IVC
Additional Tributaries
Right gonadal vein: Drains testes or ovaries into IVC
Left gonadal vein: Drains into left renal vein before IVC
Lumbar veins: Drain posterior abdominal wall
The Hepatic Portal System
Transports digested nutrients from the GI tract to the liver
2 capillary beds
1. Stomach and intestines (nutrients absorbed)
2. Liver sinusoids (nutrients processed)
Haptic Portal Vein
Formed by junction of superior mesenteric vein and splenic vein
Carries nutrient-rich blood to the liver
- Blood detoxified
Nutrients processed and stored
Tributary Veins of Hepatic Portal Vein
Superior mesenteric vein: Drains small intestine, ascending and part of transverse colon
Splenic vein: Drains spleen, pancreas, part of stomach
Inferior mesenteric vein: Drains descending colon, sigmoid, rectum; joins splenic vein
Other Veins of Hepatic Portal System
Gastric veins: Drains stomach into hepatic portal vein
Right gastroepiploic vein: Drains greater curvature of the stomach to splenic vein then hepatic portal vein
Veins of the Pelvis and Lower Limbs
Deep veins: Follow corresponding artery
Superficial veins
- Great saphenous vein: Drains thigh, medial lower leg, and foot into femoral vein
Small saphenous vein: Drains posterior lower leg and foot into popliteal vein
Veins of the Pelvis
Common iliac vein: Drain lower limb, pelvis and abdominal organs into IVC
Internal iliac vein: Drains pelvis into common iliac vein
External iliac vein: Drains lower limb into common iliac vein
Veins of the Thigh
Femoral vein: Drains thigh, deep leg structures into external iliac vein
Popliteal vein: Drains knee, lower leg, collects from small saphenous vein, empties into femoral vein
Veins of the Leg
Fibular vein: Drains lateral lower leg into posterior tibial vein
Anterior tibial vein: Drains anterior lower leg into popliteal vein
Posterior tibial vein: Drains posterior lower leg into popliteal vein
Dorsal Veins of the Ankle and Foot
Dorsalis pedis vein: Drains dorsum of foot/ankle into anterior tibial vein
Dorsal venous arch: Drains dorsum into dorsalis pedis vein and great saphenous vein
Dorsal metatarsal veins: Drain metatarsal region into dorsal venous arch
Plantar Veins of the Ankle and Foot
Plantar veins: Drain plantar surface into posterior tibial vein and fibular vein
Deep plantar arch: Drain deep plantar structures into posterior tibial vein
Digital veins: Drain digits into plantar veins and dorsal venous arch
Aneurysm
Abnormal bulge in artery wall
- Weakness in vessel wall
Life-threatening internal bleeding if ruptured
Common sites: Abdominal aorta and cerebral arteries
Deep Vein Thrombosis
Blood clot (embolus) forms in deep vein
Can cause pulmonary embolism if it travels to lungs
Most common in femoral and popliteal veins
Varicose Veins
Swollen, twisted veins in legs
Weakened or damaged valves
- Backflow of blood
Cause discomfort and swelling
Most common in superficial veins
Atherosclerosis
Fatty plaques build up in arteries
Arteries narrow and harden
- Restrict blood flow
Leads to heart disease or stroke
Most common in coronary and carotid arteries
Hypertension
High blood pressure damages artery walls
Can lead to heart disease or stroke
Most common in coronary, carotid, and renal arteries
