Download Circulatory System

Circulatory System
Objectives
Understand the roles of the cardiovascular and lymphatic systems and
their relationship to each other
Know the tissue layers that characterize blood vessels
Know the anatomical and functional differences between arteries, veins
and capillaries
Distinguish systemic and pulmonary circulation and portal circulation
Describe differences in adult and fetal circulation with respect to the
hepatic portal and pulmonary systems
Know the cellular components of blood
Know where hematopoeisis occurs and where blood cells are removed
from circulation
Know the relationship of cerebrospinal fluid (CSF) to blood
Relate the function of the following organs to the circulatory system:
spleen, thymus, lymph nodes, tonsils, carotid bodies, hypothalamus,
brown fat, lungs, kidneys, liver, bone marrow, endocrine glands,
choroid plexus
Major divisions of the circulatory system
Cardiovascular system
functions
distributes nutrients, wastes, O2, CO2, hormones
thermoregulation, osmoregulation, physiological homeostasis
components
heart, arteries, veins, capillaries
blood
Lymphatic system
Major divisions of the circulatory system
Lymphatic system
functions
immune response, lipid absorption, returns fluids from
tissues to venous cardiovascular system
components
Lymph Capillaries, Vessels, Ducts
Lymph Organs
Lymph Nodes
Thymus
Spleen
Tonsils
Peyer’s Patches
Vermiform Appendix
Lymph
Layers of the cardiovascular system
listed from luminal to superficial:
Vessels
Endothelium
Tunica Intima
Muscle and CT
Tunica Media
Covering
Tunica Adventitia
General terms
Collateral Circulation
Anastomosis
Heart
Endocardium
Myocardium
Pericardium
Arteries
by definition: conduct blood away from heart
typically conduct O2-rich blood
exceptions are pulmonary arteries and umbilical arteries
narrow diameter (than veins)
thicker wall (than veins)
Tunica Intima maybe Stratified Squamous Epithelium
Tunica Media alternating bands of Smooth Muscle and Elastic CT
high pressure
located deep (not merely subcutaneous) except to pass joints
typically co-occur with veins and nerves of same name
Veins
by definition: conduct blood towards the heart
typically conduct O2-depleted blood
exceptions are pulmonary veins and umbilical vein
large diameter
thin wall
low pressure
passive valves
two tier system of both superficial (subcutaneous) and deep vessels
Capillaries
leaky vessels
consist only of Tunica Intima only
Blood
Plasma – extracellular matrix
water, dissolved salts, proteins, nutrients, urea, hormones, CO2
Albumin – osmolarity
Fibrinogen – clotting
Globulins – immune response
Formed elements of blood – cellular
Hematopoeisis from pleuripotent stem or progenitor cells
Red Bone Marrow in adults
Yolk Sac, Spleen, Liver, Kidneys in embryo and fetus
Erythrocytes or Red Blood Cells (RBC’s)
carry hemoglobin, four-ringed protein that binds iron (hence O2)
most numerous blood cell type
biconcave
anucleate
7.5 µm in diameter
Rollo formation
~120 day lifespan
unlike leucocytes, RBC’s cannot escape capillaries
Leucocytes or White Blood Cells (WBC’s)
Granulocytes or Polymorphonuclear Cells
extracellular digestion by release of lytic enzymes
innate immune response
types distinguished by hemotoxylin and eosin (H&E) staining
Neutrophils – neutral pH, red and blue
most numerous granulocyte, major constituent of pus
Eosinophils – acid, red
Basophils – basic, blue
produce edema, release heparin and histamine
Agranulocytes
Monocytes or Macrophages (mature)
amoeboid cells, internal digestion by phagocytosis
Lymphocytes
many types: t-lymphocytes, b-lymphocytes, natural killer-lymphocytes
recognize, target, and kill antigens
adaptive immune response
Thrombocytes or blood platelets
small pieces of cells involved in clotting
Heart
Pericardial cavity – middle mediastinum
Parietal Pericardium
Serous Pericardium
Fibrous Pericardium
Heart suspended by great vessels superiorly (anterior and posterior)
tissue layers of heart
Visceral pericardium (or simply “pericardium”) – serosa
Myocardium – cardiac striated muscle
Endocardium – simple squamous epithelium
margins of the heart
superior – sternal angle to 4th thoracic intervertebral disc
right – ½ inch parasternal
apex – left midclavicular line or ½ inch medial to areola in males
inferior – xiphisternal joint to 8th thoracic intervertebral disc
Pulmonary circulation – to and from lungs
Systemic circulation – to and from body
Intrinsic circulation of the heart
Hepatic Portal circulation
separated as right and left chambers of the heart
2 Atria (s. atrium)
2 Ventricles
Interatrial Septum
Interventricular Septum
Atrioventricular Septum
Systemic circulation
Superior vena cava – from upper ½ body
Inferior vena cava – from lower ½ body
Coronary sinus – intrinsic circulation of heart
↓
Right atrium
↓
Right ventricle
↓
Pulmonary circuit
Pulmonary trunk to pulmonary arteries
Lungs
Pulmonary veins
↓
Left atrium
↓
Left ventricle
↓
Systemic circulation
Ascending Aorta – to everything
General features of Atria
smaller and thinner walled than ventricles
Musculi Pectinati
Auricles
Atria separated from one another by Interatrial Septum
Atria separated from ventricles by Atrioventricular Septum
contains Atrioventricular (AV) Node – beginning of Moderator Band
Right Atrium
Sinus Venosus
posterior right, smooth surface
receives Superior and Inferior Venae Cavae and Coronary Sinus
Crista Terminalis
Sinoatrial (SA) Node – the “pacemaker”
Fossa Ovalis – vestige of Foramen Ovale (fetal interatrial bypass)
Left Atrium
receives Upper and Lower Right and Upper and Lower Left Pulmonary Veins
General Features of Ventricles
larger and thicker walled than atria
Trabeculae Carnae
Atrioventricular (AV) Valves – active, muscular
Cusps
Chordae Tendinae
Papillary muscles
Semilunar Valves – passive
Ventricles separated from one another by interventricular septum
contains Moderator Band or Purkinje Fibers
Right Ventricle
Right AV or Tricuspid Valve – three cusps
opening of Pulmonary Trunk – anterior superior left
Pulmonary Semilunar Valve
Left Ventricle
Left AV or Bicuspid or Mitral Valve – two cusps
opening of Ascending Aorta – anterior superior right
Aortic Semilunar Valve
Electrical conduction of the heart
Sinoatrial Node – pacemaker
Atrioventricular Node
Moderator Band or Bundle of HIS or Purkinje Fibers
Locations to listen to heart valves
Aortic Semilunar – Right 2nd intercostal space parasternal
Pulmonary Semilunar – Left 2nd intercostal space parasternal
Tricuspid – Right 5th intercostal space parasternal
Bicuspid or Mitral – Left 5th intercostal space midclavicular
Fetal circulation
fetal structure
fate
R&L Umbilical Arteries
Umbilical Vein
Ductus Venosus
(also Portal Sinus
Foramen Ovale
Ductus Arteriosus
Vesical Arteries and Median Umbilical Ligament
Ligamentum Teres in Falciform Ligament
Ligamentum Venosus
Hepatic Portal Vein)
Fossa Ovalis
Ligamentum Arteriosum
Fetal
Definitive
Branches of the Thoracic Aorta
listed in order of branching
Ascending Aorta
Right and Left Coronary Arteries
Aortic Arch
Brachiocephalic Artery
branches: Right Common Carotid and Right Subclavian Arteries
Left Common Carotid Artery
Left Subclavian Artery
Descending Aorta
segmental Esophageal and Intercostal arteries
Superior Vena Cava
venous counterpart to the Thoracic Aorta
drains entire upper half of body
located to right side of Aortic Arch, on mediastinal surface of right lung
begins with the union of Right and Left Brachiocephalic Veins
terminates in Sinus Venosus of Right Atrium
Tributaries
Left Brachiocephalic or Left Innominate Vein
long, horizontal, anterior to branches of aortic arch
begins with union of Subclavian and Internal Jugular Veins
Right Brachiocephalic or Right Innominate Vein
short, vertical
begins with union of Subclavian and Internal Jugular Veins
Azygos Vein
drains right Intercostal Veins
drains left Intercostal Veins via Hemiazygos Veins
Branches of the Abdominal Aorta
listed in order of branching
Coeliac Trunk – to superior abdominal organs
Superior Mesenteric Srtery – to Jejunum, Ileum, Large Intestine up to
and includingTransverse Colon
Right and Left Renal Arteries
Right and Left Gonadal (Testicular or Ovarian) Arteries
Inferior Mesenteric Artery – to Descending and Sigmoid Colons and
superior Rectum
Right and Left Common Iliac Arteries – to pelvic region and lower limbs
Inferior Vena Cava
venous counterpart to the Abdominal Aorta
drains entire lower half of body
its main tributaries are those corresponding only to paired arterial
branches of the Abdominal Aorta, except the Hepatic vein
located to right side of Abdominal Aorta, anterior to lumbar vertebrae
begins with the union of the Right and Left Common Iliac veins
terminates in Sinus Venosus of Right Atrium
Tributaries of the Inferior Vena Cava
listed in order of union
Right and Left Common Iliac Veins
Right Gonadal (Testicular or Ovarian) Vein
simultaneously because they are paired:
Right Renal Vein
Left Renal Vein
Left Renal Vein - long, crosses anterior to Abdominal Aorta
tributary of Left Renal Vein:
Left Gonadal (Testicular or Ovarian) Vein
Hepatic Vein
Arterial Branches
Intrinsic circulation of the heart
“Coronary” Arteries vs “Cardiac” Veins
Branches of Right Coronary Artery
Marginal (coronary) Artery
on right margin of heart
Circumflex (Coronary) Artery (right side)
at Atrioventricular Septum
Branches of Left Coronary Artery
Anterior Interventricular or Descending Artery
at anterior interventricular septum
anastomoses with Posterior Interventricular Artery
Circumflex (Coronary) Artery (left side)
branch:
Posterior Interventricular or Descending Artery
at posterior interventricular septum
anastomoses with Anterior Interventricular Artery
Cardiac veins
Small Cardiac Vein
corresponds to Marginal Artery
on right margin of heart
Great Cardiac Vein
corresponds to Anterior Interventricular Artery
at anterior interventricular septum
Middle Cardiac Vein
corresponds to Posterior Interventricular Artery
at Posterior Interventricular Septum
Coronary Sinus
alongside Circumflex Artery
at Atrioventricular Septum
receives Cardiac Veins and
drains into Sinus Venosus of Right Atrium
Branches of the Common Carotid Arteries and their
branches
Internal Carotid Artery
major branches of the Internal Carotid Artery:
Middle Cerebral Artery –
to majority of Cerebrum via Carotid Canal
passes through the Cavernous Sinus (a venous “dural sinus”
surrounding the sella turcica)
Ophthalmic Artery – to orbit via optic canal
select branches of Ophthalmic Artery:
Central Artery – enters eye within optic nerve
branches of the Central Artery
Superior and Inferior Temporal Arteries – to retina
Superior and Inferior Nasal Arteries – to retina
Supraorbital Artery
External Carotid Artery
(continued)
Branches of the External Carotid Artery and its branches
Lingual Artery – to tongue
Facial Artery – crosses face from mandibular ramus to medial orbit
Superficial Temporal Artery – to temporal fossa, scalp
Occipital Artery
Maxillary Artery – to muscles of mastication, palate, teeth, and
infraorbital region
select branches:
Sphenopalatine Artery – to nasal cavity and palate
Middle Meningeal Artery – to cranial cavity via foramen spinosum
Alveolar Arteries (3) – to teeth
Infraorbital Artery – to middle face
Branches of the Subclavian Arteries and their branches
Vertebral Artery – to cranial cavity via foramen magnum
Thyrocervical Trunk – to scapular and cervical regions
Internal Thoracic Artery
Costocervical Trunk
Dorsal Scapular Artery
Axillary Artery (terminal branch)
Subclavian Artery → Axillary Artery at first rib
to anterior and lateral thoracic regions
branches:
Thoracoacromial Artery (travels with Lateral Pectoral nerve)
Subscapular Artery
Lateral Thoracic artery (travels with Long Thoracic nerve)
Circumflex Humeral Artery
Brachial Artery (terminal branch)
Axillary Artery → Brachial Artery at Teres Major muscle
(continued)
Major Branches of the Brachial Artery
Profunda Brachii Artery
Superior and Inferior Ulnar Collateral Arteries
Radial Artery (terminal branch)
Deep Palmar Arch – anastomoses with Ulnar Artery
Ulnar Artery (terminal branch)
Common Interosseous Artery
Anterior Interosseous Artery
Posterior Interosseous Artery
Superficial Palmar Arch – anastomoses with Radial Artery
Circulation of the cranial cavity
1) Internal Carotid Artery → Middle Cerebral Artery (at carotid canal)
serves frontal, parietal, and temporal lobes of the cerebrum
passes through Cavernous Sinus (a venous plexus of the dural
sinuses)
four levels from deep to superficial
emerges through Central Sulcus or Fissure between frontal and
parietal lobes of cerebrum
emerges through Sylvian or Lateral Sulcus or Fissure between frontal
and temporal lobes of cerebrum
branches:
Anterior Cerebral Artery - to anterior inferior frontal lobe
Right and Left Anterior Cerebral Arteries anastomose via:
Anterior Communicating Artery
Posterior Communicating Artery – an anastomosis with posterior
cerebral artery
(continued)
Circulation of the cranial cavity
2) Right and Left Vertebral arteries anastomose to form:
Basilar artery (unpaired)
branches:
Cerebellar arteries
Posterior cerebral artery – terminal paired branches
anastomoses with middle cerebral artery via posterior
communicating artery
3) Middle meningeal Artery – to meninges and calvarium
Branches of the coeliac trunk and their major branches
Left Gastric Artery
branches to lesser curvature of stomach and esophagus
Common Hepatic Artery
branches:
Hepatic Artery
Gastroduodenal Artery
branches to (right side of) greater curvature of stomach,
duodenum, and head and neck of pancreas
Splenic Artery
branches to fundus and (left side of) greater curvature of stomach,
and body and tail of pancreas
Branches of Common Iliac arteries and their major branches
Internal iliac Artery
branches:
Iliolumbar Artery (serves iliopsoas muscle)
Lateral Sacral Artery
Superior and Inferior Gluteal Arteries
Umbilical Artery of fetus…
or Superior Vesical Artery of adult
Uterine and Vaginal Arteries of female…
or Inferior Vesical Artery of male
Middle Rectal (“Middle Hemorrhoidal”) Artery
Obturator artery – to obturator muscles
Internal Pudendal Artery - to perineum
Branch (one among many):
Inferior Rectal (“Inferior Hemorrhoidal”) Artery
External Iliac artery
(continued)
Branches of Internal Iliac artery
Branches of
Internal Iliac artery
Branches of External Iliac Artery and its branches
Inferior Epigastric artery
Circumflex Iliac artery
Femoral Artery (terminal branch)
external iliac Artery → femoral artery at inguinal ligament
Branches of Femoral Artery:
External Pudendal arteries – to external genitalia, i.e., scrotum in
males or labia majora in females
Profunda Femoris Artery – to muscles of medial and posterior
compartments
Medial and Lateral Circumflex Femoral Arteries – branches
descend medial and lateral thigh
Popliteal Artery (terminal branch)
Femoral Artery → Popliteal Artery at adductor hiatus
(continued)
Branches of Popliteal Artery and their major branches
Genicular arteries (superior medial and lateral, inferior medial and lateral)
Sural Arteries
Anterior Tibial Artery (terminal branch of Popliteal Artery)
branch (terminal):
Dorsalis Pedis Artery
Posterior Tibial Artery (terminal branch of Popliteal Artery)
branches:
Peroneal Artery
Medial and Lateral Plantar Arteries (terminal branches of
Posterior Tibial Artery)
Pulse
Superficial Temporal Artery
temporal fossa
Carotid Artery (Common or External)
anterior to sternocleidomastoid at level of laryngeal eminence
Brachial Artery
antecubital fossa medial to tendon of biceps brachii
Radial Artery
anterior distal radius
Femoral Artery
femoral triangle
Popliteal Artery
popliteal fossa
Posterior Tibial Artery
posterior to medial malleolus
Dorsalis Pedis Artery
between tendons of extensor hallucis longus and extensor digitorum
longus
Venous drainage of the Head and Neck
for most arteries there are corresponding veins of the same name except:
Internal, External, and Common Carotid arteries
veins with no corresponding arteries:
Internal Jugular vein
drains cranial cavity, anterior face, tongue and pharynx
Sigmoid Dural Sinus → Internal Jugular vein at jugular foramen
major tributaries:
Facial Vein
Lingual Vein
External Jugular Vein
drains lateral and posterior scalp, posterior face, infratemporal fossa
major tributaries:
Maxillary Vein
Superficial Temporal Vein
Anterior Jugular Vein
drains superficial thyroid region
Brain Ventricles, Cerebrospinal Fluid, Meninges, Dural Sinuses
Choroid Plexus – a capillary-like structure within some ventricles
Cerebrospinal Fluid (CSF) – blood filtrate produced by choroid plexus that
bathes the central nervous system from within and without
Structures filled with CSF:
Subarachnoid Space
Brain Ventricles - derivatives of the embryological neural tube (CNS)
Lateral Ventricles – in paired cerebral hemispheres of forebrain
Third Ventricle – between right and left thalami and within
hypothalamus of forebrain
Cerebral Aqueduct – narrow tube in midbrain
Fourth Ventricle – between cerebellum and pons of hindbrain
Central Canal of the spinal cord
Meninges
Pia Mater
Arachnoid Mater
Subarchnoid Space – location of CSF between pia and
arachnoid maters
Arachnoid Villi – drain CSF from subarachnoid space to dural sinuses
Dura Mater
continuous with periosteum of calvarium and vertebral canal
extensions of dura extending into fissures of brain:
Falx Cerebri – midsagittal septum between cerebral hemispheres
Falx Cerebelli – midsagittal septum between cerebellar
hemispheres
Tentorium Cerebelli – horizontal septum between occipital
lobes of cerebrum and cerebellum
Dural Sinuses
Superior Sagittal Sinus – superior margin of falx cerebri inferior to
sagittal suture
Inferior Sagittal Sinus – along inferior margin of falx cerebri
Straight Sinus – along union of falx cerebri and tentorium cerebelli
Transverse Sinuses – along lateral margin of tentorium cerebelli
Superior Sagittal Sinus → Right Transverse Sinus at internal occipital
protuberance
Straight Sinus → Left Transverse Sinus at internal occipital
protuberance
Sigmoid Sinuses
continuation of Transverse Sinuses
sigmoid sinus → Internal Jugular Vein at jugular foramen
(continued)
Dural Sinuses
Cavernous Sinus
venous plexus surrounding Sella Turcica
passed through by Internal Carotid Artery, nIII, nIV, nV1, nV2, nVI
receives Ophthalmic Vein*
drains indirectly to Transverse and Sigmoid sinuses
* Facial Vein anastomoses with Ophthalmic Vein, unlike arteries of
same names – this is a superficial venous pathway into the cranial
cavity and potential source of infection
Hepatic Portal Vein
terminates in liver
tributaries:
Splenic Vein
Superior Mesenteric Vein
Inferior Mesenteric Vein
Venous drainage of the upper extremity and girdle
for every artery there are corresponding veins of the same name
Superficial veins with no corresponding arteries:
Cephalic Vein
drains dorsum of hand, lateral antebrachium and brachium
ends in Axillary Vein at Deltopectoral Triangle
Basilic Vein
Anterior medial antebrachium and medial brachium
ends in Brachial Vein
Median Cubital Vein
Antecubital anastomosis of Cephalic and Basilic Veins
Venous drainage of the lower extremity and pelvic region
for every artery there are corresponding veins of the same name
Superficial veins with no corresponding arteries:
Great or Long Saphenous Vein
drains medial crus and thigh
ends in Femoral Vein in femoral triangle
Short Saphenous Vein
drains sural region
ends in Popliteal Vein in popliteal region
Lymphatic system
Functions
Immune response
lipid absorption
removes dead blood cells from circulation, produces bilirubin
returns fluids and mobile leucocytes from extracellular tissues to
venous cardiovascular system
Terminal lymph vessels
Right Lymphatic duct
drains upper right ¼ of body
terminates in right subclavian vein
Thoracic duct
drains all but upper right ¼ of body
terminates in left subclavian vein
Cysterna Chyli – bulb-like expansion of inferior end of thoracic duct
Lymph Nodes
scattered and concentrated in locations throughout body, especially
major joints, the cervical region, and digestive organs
Leucocytes within nodes attack antigens and impede them from circulating
Afferent and Efferent lymph vessels - lead to and from nodes
parts of the node:
Capsule
Trabeculae
Nodules
Germinal Centers
site of maturation and acquisition of new antibodies by b-lymphocytes
and their clonal proliferation
Reticular fibers
Macrophages and Lymphocytes
Distribution of Select Major Groups of Lymph Nodes
of head:
Parotid
Submaxillary or Submandibular
Occipital
of neck:
Cervical
superior and inferior deep – surround internal jugular veins
Superficial – superior anterior triangle
(continued)
Distribution of Select Major Groups of Lymph Nodes
of upper limb and girdle:
Axillary
Pectoral, Subclavicular, Subscapular, Brachial
of lower limb and girdle (including genitals and perineum):
Inguinal – femoral triangle
of thoracic cavity:
Tracheobronchial, Intercostal
Mediastinal – mostly concentrated around arteries
of abdominal Cavity:
Lumbar – efferents to cisterna chyli
many groups, mostly concentrated around and named after all arteries
and their branches, as well as viscera of pelvic cavity (e.g., rectum)
Thymus
site of maturation of t-lymphocytes primarily in youth
located posterior to manubrium in superior mediastinum
size at age 2 (maximal): from laryngeal eminence to mid-sternal body
size at adolescence (replaced by adipose): jugular notch to sternal angle
Spleen
blood filter
removes dead erythrocytes from circulation
populated by monocytes and macrophages
degrades hemoglobin to bilirubin (subsequently excreted by liver)
located in left hypogastric region, to left of stomach
Capsule
Cords of Billroth – reticular fibers