Module 4 CVS, Respi, BLS Flashcards
The Cardiovascular system consists of the following structures:
- HEART
- ARTERIES
- VEINS
- CAPILLARIES
- The LYMPHATICS
Cardiovascular system: Functions
- Transport of oxygen and nutrients to the tissues
- Transport of carbon dioxide and other metabolic waste products from the tissues
- Temperature regulation
- Distribution of molecules (eg. Hormones and cells)
Functional components of the Cardiovascular System:
- Blood vascular system
2. Lymph vascular system
3 Basic Components of Cardiovascular System:
- Endothelium- lining of the inner surface of the cardiovascular system
- Smooth Muscles- capillaries and post capillaries venules does not have.
- Connective Tissue- made up of collagen, elastic fibers
ground substance of glycolproteins and proteoglycans.
Influenced by:
mechanical factors – BP
metabolic factors – local needs
3 Layers of the 4 Chambers:
- Endocardium
- Myocardium
- Epicardium
Endothelium(simple squamous) –endothelial cells
- subendocardium : thick loose c.t.
- Purkinje fibers
ENDOCARDIUM
- modified cardiac muscle
- decrease number of myofibrils limited to the periphery
- lack transverse tubules
- larger diameter
- more sarcoplasm and glycogen(pale)
- rounded nuclei in groups of 2 or more
Purkinje fibers
thickest and most prominent layer, with strands of connective tissue and vascular network in between cells
MYOCARDIUM
• striated, involuntary
• cylindrical / elongated, w/ branching ends
• mono- / binucleated
*INTERCALATED DISCS —transverse lines at the ends of the branching fibers
Cardiac Muscle Tissue
INTERCALATED DISCS
- Fascia adherens / junctions - most prominent; anchoring sites
- Desmosomes / Macula adherens - cardiac cells binding
- Gap junction - ionic continuity
* Intercalated disc- found at the branches of the muscle
- visceral layer of pericardium mesothelial cells-outer surface, secretes lubricating fluid
- fluid is used so that visceral and parietal pericardium can slide freely during contraction of the heart
EPICARDIUM
- contain blood vessels, nerves, and fat cells
- pericardial cavity and sac
subepicardium
Muscles of the Heart
- Trabecula carnae- it is found arising from both ventricles.
- Papillary muscle- extension of the ventricular myocardium, it is where the corda tendinae are attached.
- Chorda tendinae- connect flops of AV to the wall of the
heart.
CARDIAC SKELETON (Dense Irregular Connective Tissue)
- Septum membranaceum - IVS; muscle attachments
- Trigonafibrosa - between arterial foramina and AV
canals - Annuli fibrosi - principal attachment for the cardiac
muscles and Atrioventricular valves
Functions of Cardiac Skeleton
- Anchors and supports heart valves
- Firm points of insertion for cardiac muscles
- Acts as electrical insulation between atria and ventricles
- is the central or main supporting structure of the heart. Though called skeleton, it is not made of bones but of dense irregular connective tissue.
Cardiac skeleton
Impulse Conducting System
- SA Node - pacemaker of the heart ; sulcus terminalis
area - AV node – below posterior leaf of aortic valve
- Bundle of His – trigonumfibrosumdextrus
- Right and Left branches
- Subendocardial network of PF
Blood vessels of the heart
coronary arteries > cardiac veins > coronary sinuses >rt atrium
Lymphatics of the Heart:
- Grooves of the heart
- Epicardial connective tissue
- Myocardium and Endocardium
It is a serious complication of rheumatic fever. It is a bacterial infection of streptococcus, in which it affects the upper respiratory tract and extends to the heart. It targets the heart valves.
Rheumatic Heart Disease
- narrowing of the lumen of the blood vessel, supplying the heart due to Atherosclerosis. Fat are deposited in the lumen called plaque. It decreases nutrients, oxygen until it completely obstructs causing
Coronary Heart Disease
- cardiac myocytes shrunken, pyknotic nuclei; dense, cloudy cytoplasm.
- coagulation necrosis
- loss of nuclei
- absence of striations
- fibrous scar
Myocardial Infarct
- tubular structures that convey blood away and towards the heart
BLOOD VESSELS
BLOOD VESSELS
Arteries : toward organ and tissue
Capillaries : anastomosing channels of small caliber vessels providing interchange of substances.
Veins : return blood to the heart
COMMON BASIC STRUCTURE
Tunica intima - innermost part, analogue in heart is
endocardium
Tunica media - middle part, analogue in heart is
myocardium
Tunica adventitia - outermost part, analogue in heart is
epicardium
Endothelium = layer of endothelial cells
Subendothelium = Loose Connective Tissue with smoothmuscle cells
*Internal elastic lamina/membrane or fenestrated membrane of Henle
* scalloped appearance
Tunica intima
- Circumferentially arranged smooth muscles, with elastic, collagen fibers III, glycoproteins and proteoglycans
- External elastic lamina/membrane
Tunica media
separates the Tunica media from Tunica adventitia in arteries
External elastic lamina/membrane
- Loose Connective Tissue
- Type I collagen and elastic fibers Vasa vasorum,
nervi vasorum - Vasa vasorum: blood supply of blood vessel (vessel of
the vessel) - Nervi vasorum: nerve supply of blood vessel
(VASOMOTOR – noerepinephrine) - Subendothelium: With fibroblasts and Myointimal cells
- Early changes of atherosclerosis
Tunica adventitia
Endothelial cells 1
- Acts as permeability barrier
- Basement membrane maintenance – synthesize collagens and proteoglycans
- Fc VIII (Von Willebrand) secretion – protective thrombus formation
- Minimize pathological thrombus – synthesize and secrete prostacyclin, thrombomodulin, NO2 (inhibits platelet adhesion )
Endothelial cells 2
- Controls blood flow – secrete vasoactive
Factors:
*VD - prostacyclin, NO2
*VC – endothelin - Mediate acute inflammatory reaction – produce IL 1,6,8 (cell adhesion molecules)
- Produce growth factors – fibroblast GF, platelet-derived GF, blood colony stimulating factor
Arteries
- Large / Elastic / Conducting
- Medium / Muscular / Distributing
- Small
* Arterioles
* Pre-capillary (Metarterioles)
Artery vs Vein
Artery- Tunica Media is thickest; it is a high pressure vessel
Vein- Tunica Adventitia is the thickest; it is a low pressure vessel
conducting / elastic arteries (aorta,pulmonary artery)
- Intima
a. endothelium- simple squamous
b. subendothelium- thin loose CT
c. indistinct IEL or Henle’s membrane –fenestrated sheet of elastin - Media- thickest, many elastic lamellae alternating with smooth muscles
- Underdeveloped adventitia with vasa vasorum
Large arteries
Medical Application: Arteries
- arteriosclerosis – hardening of arteries
- atherosclerosis – fibrous deposits(atheroma)
- aneurysm – dilatation /weakening (wall)
- thickening of Tunica intima
- deposition of lipid and fibrous material
- plaque or atheroma
- scarring/ calcification of wall
- mainly associated with elastic artery and coronary artery
Atherosclerosis
Remember (Large Arteries)
*Large Arteries- large amounts of elastic fibers; check the Tunica Media as identification as is it very thick, while the Tunica Adventitia is underdeveloped
- distributing / muscular arteries
1. Intima - prominent” Internal elastic lamina
2. Media - “External elastic lamina”— wavy fenestrated lamella of elastic fibers; separates media from adventitia
3. Adventitia - Loose Connective Tissue - vasa vasorum , nervi vasorum
Medium sized arteries
- (Arterioles / transitional arterioles / precapillary or metarteriole)
- isolated spirally arranged smooth muscle fibers; no EEL
- 1-2 layers
- 1.0-.1 mm diameter
- regulate distribution of blood to the capillary beds
- Maintain blood pressure
Small arteries/resistance arteries
- thin walled tubes which branches extensively
- Smallest, No smooth muscle
- PERICYTES only(contractile cells)
- layers: tunica intima –single layer of endothelial cells with thin tunica adventitia
- microcirculation
- exchange metabolites by diffusion to and from cells
- accommodate 1-2 RBC only (>2—venule)
Capillaries : (90%)
are common on capillaries and on postcapillary venules
Pericytes (Rouget cells)
MICROCIRCULATION: Types of flow
- Nutritional flow
2. Non-nutritional / shunt flow – metarteriole
MICROCIRCULATION: Types of capillary
- True capillary
2. Thoroughfare/preferential channels
Functions of the microcirculation
- Regulate blood flow and tissue perfusion
- Regulate blood pressure
- Regulate tissue fluid (swelling or edema)
- Delivery of oxygen and other nutrients and removal of CO2 and other metabolic waste products
- Regulate body temperature
- Role in inflammation.
Types of Capillary (according to wall structure)
- Continuous
- Fenestrated
- Sinusoidal
- complete layer
- lack of pore
- in muscle, exocrine glands, lungs, skin and nervous
tissue
Continuous
- with pores or fenestrae
- found in kidney, intestine, choroid plexus and endocrine
glands
** diaphragm
Fenestrated
- tortuous path and greatly enlarged diameter
- absence of continuous basal lamina and lining in walls
- presence of multiple fenestrations and phagocytes in liver
and hematopoietic organs
***Sinuses - barrel-like arrangement of cells - spleen
Sinusoidal
Exchange in continuous capillary:
- Passive diffusion
- Pinocytic vesicles
- Intercellular junctions
- capacitance / reservoir / compliance vessels
- larger caliber , thinner walls than arteries
- more collagen 70% TBV
Veins
3 Layers of the Vein
Tunica Adventia– collagenous connective tissue in large amount
Tunica Media– sparse circular muscle loosely arranged
Tunica Intima – endothelial layer
- Postcapillary, collecting and muscular venules drain
capillary beds - site of leukocyte
- exit from vasculaturelarge lumen, very thin wall
- 2-3 layers smooth muscles
Small Veins
- 3-5 layers smooth muscles
- with valves
Medium size veins
- prominent VALVES
- > 5 layers smooth muscles
- Vena cava
Large muscular vein
- smallest, union of capillaries
- sluggish flow
- no smooth muscle
- main site of WBC migration into and out of circulation
Post-capillary venules
larger, more pericytes
Collecting venules
- larger
- smooth muscle layer
Muscular venules
The venous system: Control of flow
- pressure gradient
- skeletal muscles
- valves (veins >2 mm)
- bundled longitudinal smooth muscle
- prominent VALVES
- SVC and IVC
Large veins
Medical application: VEINS
a. Thrombophebitis– occlusion and swelling
b. Varicosities – wall weakness, luminal P, valve defects
Eg. Saphenous vein, hemorrhoids, esophageal varices, varicocele
Special veins
No smooth muscle – cerebral, meningeal, dural sinuses, retina, penis, placenta
Rich in smooth muscle – gravid uterus, limbs, umbilical, mesenteric
ALTERNATIVE PATHWAYS
- Portal system – (cap > veins > cap > circulation)
Venous – hepatic portal system (Liver)
hypothalamo-hypophyseal portal system
Arterial – Kidney
- afferent arteriole–cap—efferent arteriole - A-V shunt – (glomus) - fingers, nailbeds, ears, nose
skin - temperature regulation and heat conservation
Lumen: smaller Thickness of wall: thicker Thickest coat: Tunica media Rigidity of wall: More rigid Internal elastic membrane: present Valves: absent Muscles and elastic tissue: More abundant Vasa vasorum: Extend up to tunica media
Artery
Lumen: bigger Thickness of wall: Thinner Thickest coat: Tunica adventitia Rigidity of wall: Less rigid Internal elastic membrane: absent Valves: present Muscles and elastic tissues: Less abundant Vasa vasorum: Extend up to tunica intima
Vein
- exits the artery, enters the veins
- no RBC ; with granulocytes and lymphocytes
- microcirculation - 2% of plasma exchange
Lymph Vascular System
- more permeable (thin endothelium)
- no basement membrane
- no pericytes have anchoring filaments
- have valves
- reticulin fibers/scanty ground substance
- capillaries—vessels—ducts
Lymphatic vessels
Layers of the Lymphatic vessel
- intima
- media
- adventitia
Two Main Vessels:
- thoracic duct
2. right lymphatic duct
Lymphatics found in almost all organs except:
CNS, bone marrow, coats of eyes, internal ear, placenta, bone, cartilage, epithelia, thymus, teeth
Lymphatic flow aided by:
Intrinsic forces
- lymphangions
- smooth ms (collecting vessels)
Extrinsic forces
- contraction – skeletal ms
- VALVES—- keeps lymph flow “unidirectional”
Sx - facilitate spread o Pathogens o Parasites o malignant cells
lymph edema
- the act of supporting an unconscious patient’s breathing and circulation in order to preserve their life and buy time for professional emergency medical attention
BLS (BASIC LIFE SUPPORT)
- set of clinical interventions for the urgent treatment of cardiac arrest, stroke and other life-threatening medical emergencies, as well as the knowledge and skills to deploy those interventions
ACLS (ADVANCED CARDIOVASCULAR LIFE SUPPORT)
IHCAs
In-Hospital Cardiac Arrests
OHCAs
Out of Hospital Cardiac Arrests
IHCA: Chains of Survival
- Surveillance and Prevention
- Recognition and activation of emergency response system
- Immediate high-quality CPR
- Rapid Defibrillation
- Advance life support and postarrest care
OHCA: Chains of Survival
- Recognition and activation of emergency response system
- Immediate high-quality CPR
- Rapid Defibrillation
- Basic and advance medical services
- Advance life support and postarrest care
Places where Cadiac Arrest happen
- Airports
- Malls/markets
- Schools
- Municipal halls
- Streets
- Homes
Untrained lay rescuers should provide __ for adult victims of cardiac arrest - until the arrival of an AED or rescuers with additional training.
compression-only (Hands-Only) CPR
In adult victims of cardiac arrest, perform
chest compressions - 100 to 120/min