Please enable JavaScript.
Coggle requires JavaScript to display documents.
A 60-year-old woman with obesity and myocardial infarction (Physiology…
A 60-year-old woman with obesity and myocardial infarction
Upstream
Direct
Body temperature
HR increases with increased body temperature
Age
Fetus has fastest HR; declines with age
Previous myocardial infarctions
Family History
Heart problems
Obesity
Trauma
Indirect
Behavior
Exercise
Increases HR
Trained athletes can have slow HR
Not having a healthy diet
Being overweight
Not taking proper care of himself
Lack of oxygen
Leads to tissue death of the heart muscle
Damaged tissue cords
Physiology
Roles of valves and papillary muscles
Papillary muscle
Project into ventricular cavity
Anchor chord tendineae that are attached to heart valves
Chordae tendineae
Anchor cusps of AV valves to papillary muscles that function to
Prevent flaps from everting back into atria
Hold valve flaps in closed position
Papillary muscles contract and chordae tendineae tighten, preventing valve flaps from everting into atria
Valves
Semilunar (SL) Valves
Aortic semilunar valve
Located between left ventricle and aorta
Pulmonary semilunar valve
Located between right ventricle and pulmonary truck
Prevent backflow from major arteries back into ventricles
Open and close in repose to pressure changes
Each valve consist of 3 cusps that roughly resemble a half moon
Semilunar valves open
As ventricles contract and intraventriclar pressure rises, blood is pushed up against semilunar valves
Semilunar valves closed
As ventricles relax and intraventricular pressure falls, blood flows back from arteries, filling the cusps oof semilunar valves
Atrioventricular (AV) Valves
Mitral Valve (left AV, bicuspid valve)
Made up of two cusps and lies between left atria and ventricle
Tricuspid Valve (right AV valve)
Made up of three cusps and lies between right atrial and ventricle
AV valves open; atrial pressure greater than ventricular pressure
AV valves closed; atrial pressure less than ventricular pressure
The normal sounds of the heart and causes
Heart Sounds
Lup
AV valves closing
The pressure in the ventricles is higher than the atria
Heart of isovolumetric contraction
Dup
Semilunar valves closing
isovolumetric relaxation
Relationship b/w heart function & blood pressure
Blood Pressure
Force per unit area that blood exerts on a vessel wall
Arterial Blood Pressure
Pulse Pressure (PP)
Additional pressure placed on arteries when heart is resting to when heat is contracting
Systolic/Diastolic: 120/80 = 40mmHg is normal
Measure of elasticity and recoil of arteries
Mean Arterial Pressure (MAP)
MAP = Diastolic + (1/3) PP
93 mmHg is normal
Average measure of pressure on arteries
Regulation
Neural Regulation
Mostly in medulla oblongata
Cardiovascular center
Sympathetic division extends to heart nodes and walls
Norepinephrine causes increase in rate and/or volume of contractions
Chemoreceptors
Senses oxygen, carbon dioxide, and pH changes within blood
Reflexes
Automatically regulates blood pressure in chemical composition
Baroreceptors
Sense pressure changes in the aorta and carotid arteries
Reflex
Automatically regulates blood pressure within arteries it senses
Autoregulation
At rest tissues will have modest amount of blood flow
When active, tissues require more nutrients and have more waste, therefore blood flow will increase
Example
Hypothermia
Controls amount of blood that enters capillary
Vasoactivation
Vasoactive chemicals are released to widen blood vessels such as the case of inflammation
Hormonal Regulation
Renin-Angiotensin System
Conserves water and raises blood pressure
Aldosterone
Increases absorption of sodium and water in kidneys which helps maintain blood volume and pressure
Antidiuretic Hormone (ADH)
Increases absorption of water in kidneys which maintains blood volume and pressure
Atrial Natriuretic Peptide
Increase urine output which decreases blood volume and pressure
Capillary Exchange
Bulk Flow
Movement of large amounts of fluids and dissolved substances
Filtation
Small solutes pass through at the arterial end but large molecules are blocked
Reabsorption
Movement of fluid back in the blood at the venous end
Diffusion
Oxygen, hormones, and nutrients diffuse from high concentration to low
Net Filtration Pressure (NFP)
Pressure differences allow certain substances to filtered or reabsorbed
NFP = (HPb-HPif) - (COPb-COPif)
Lymphatic system
Pick up excess fluid and filters it before returning it to the venous circulation
The difference between hydrostatic pressure and colloid osmotic pressure
Blood flow
Peripheral Resistance
Inversely related, as resistance increases, blood flow decreases
Factors
Vessel length
Vessel radius
Blood viscosity
Amount of friction blood experiences when transported through vessels
Pressure gradient
Directly related, as blood pressure gradient increases, total blood flow is greater
Venous Return
PP = 0
Facilitated by valves
Skeletal muscle pump
Muscles contract to squeeze veins and propel blood towards the heart
Aids movement of blood within the limbs
Respiratory pump
Aids moment of blood within thoracic cavity
Pressure differences pulls blood up to the pericardial cavity
Relationship b/w heart function & respiratory rate
The cardiovascular system delivers oxygen and nutrients; carries away wastes
The respiratory system carries out gas exchange: loads oxygen "pump" aids venous return
The Heart is a transport system with 2 side by side pumps
Left side
Pumps blood to body tissue through systemic circuit
Right side
Pumps blood to lungs to get rid of CO2 and pick up O2 through pulmonary circuit
Receiving chambers of heart
Left atrium
Receives blood returning from pulmonary circuit
Right atrium
Receives blood returning from systemic circuit
Pumping chambers of heart
Right ventricle
Pumps blood through pulmonary circuit
Left ventricle
Pumps blood through systemic circuit
Functions of the Cardiovascular System
Protection
Plasma Proteins
Platelets
Leukocytes
Regulation
Body Temperature
Body pH
Fluid Balance
Transport of Vital nutrients
Nutrients
Oxygen
Hormones
Metabolic Wastes
Adequate Perfusion
Delivers sufficient blood to maintain the health of all body cells
Concepts relating to the heart
Cardiac output
Congestive heart failure
Coronary atherosclerosis
Clogged arteries caused by fat buildup
Persistent high blood pressure
Aortic pressure >90 mmHg causes myocardium to exert more forces
Multiple myocardial infarcts
Heart becomes weak as contractile cells are replaced with scar tissue
Dilated cardiomyopathy
Ventricles stretch and become flabby
Mean arterial pressure
The average pressure in a patient's arteries during one cardiac cycle
Stroke volume
Volume of blood pumped out by one ventricle with each beat
Correlates with force of contraction
Main factors that affect SV
Contractility
Increased contractility lowers ESV
Decreased by negative inotropic agents
Contractile strength at given muscle length
Afterload
Back pressure exerted by arterial blood
Pressure that ventricles must overcome to eject blood
Hypertension increases afterlload, resulting in increased ESV and reduced SV
Preload
Cardiac muscle cells are stretched just before they contract
Changes in preload cause change in SV
Degree of stretch of heart muscle
Cardiac muscle exhibits a length-tension relationship
At rest, cardiac muscle cells are shorter than optimal length
Leads to dramatic increase in contractile force
Stretching of cardiac muscle is venous return
Slow heartbeat and exercise increase venous return
Increased venous return distends ventricles and increase contraction force
Heart Rate
Number of heartbeats per minute
Adult Normal Heart Rate
60-100 bpm
Bradycardia
Condition of a heart rate below 60 bpm
Tachycardia
A condition of a heart rate consistently above 100 bpm
Heart Rate can be regulated by
Chemicals
Hormones
Epinephrine from adrenal medulla increases heart rate and contractility
Ions
Intra and extracellular ion concentration must be maintained for normal heart function
Other factors
Gender
Females have faster HR than males
Exercise
Increases HR
Trained athletes can have slow HR
Age
Fetus has fastest HR; declines with age
Body temperature
HR increases with increased body temperature
Autonomic nervous sytem
Sympathetic nervous system can be activated by emotional or physical stressors
Norepinephrine is released and binds to adrenergic receptors on heart, causing:
Pacemakers to fire more rapidly increasing HR
Increased contractility
Peripheral Resistance
The resistance to blood flow resulting from the friction of blood against the walls of vessels
Downstream
Direct effects of a failed mitral valve
Valve doesn't close tightly
Causing blood to flow backward in your heart
Blood can't move through your heart, therefore it can't get to the rest of the body
Making you feel tired or out of breath
This is known as mitral valve prolapse
Leakage can increase blood volume and pressure in the area
The increased blood pressure in the left atrium can increase pressure in the veins leading from the lung to the heart
Buildup of calcium can keep it from working as it should
Consequences in the body
If regurgitation is severe, increased pressure may result in congestion (fluid build-up) in the lungs
Can also cause palpitation, especially when lying on the left side
Blood doesn't flow normally
Increases the risk for blood clots that may cause a stroke
Affect the systems
Respiratory
Heat may enlarge to maintain forward flow of blood
Causing the heart to not pump enough blood to the body
May produce shortness of breath during:
Coughing
Exertion
Congestion around the heart and lungs, swelling of the legs and feet
"pump" aid venous return; carries away waste but it can't do it w/o the mitral valve functioning properly
Urinary
Peripheral edema that is associated with nephrotic syndrome
Leading to loss of plasma proteins in urine
Failure in a mitral valve will prevent proper regulation of blood volume and pressure
Urine flows backwards into the ureters when bladder pressure increases during voiding
Nervous
If regurgitation occurs the ANS regulation won't be able to maintain blood pressure and control the blood flow to skin for thermoregulation
The imbalanced background of autonomic nervous firing leads to disharmonized synthetic
Symptoms
If more sever regurgitation
Fatigue
Shortness of breath
Coughing
Rapid breathing
Heart palpitation
Heart may skip beats
Happens more when laying on left side
Chest pain
Mild regurgitation
You won't notice any symptoms
Anatomy
Anatomy of the Heart
Chambers
Right Ventricle
Located in the right inferior portion
Blood comes from the right atrium and is sent to the lungs
Left Atrium
Located in the left superior portion
Blood comes from the lungs and is sent to the left ventricle
Right Atrium
Located in the right superior portion
All blood enters the heat here to be sent to the right ventricle
Left Ventricle
Located in the left inferior portion
Blood comes from the left atrium and is sent systemic
Internal Sepra
Interatrial Septum
Separates the atria internally
Interventricular Septum
Separates the ventricles internally
External Sulci
Coronary Sulcus
Extends the circumference of the heart to separate the atria and the ventricles externally
Posterior Interventricular Sulcus
Extends inferiorly from the coronary sulcus to separate the ventricles posteriorly
Anterior interventricular sulcus
Extends inferiorly from the coronary sulcus to separate the ventricles anteriorly
Layers of Heart Wall
Myocardium
Composed of cardiac muscle tissue
Embedded with intercalated discs
Results in chambers acting as a functional syncytium
Contains desmosomes which anchor the muscle cell together
Involuntary striated muscle
Endocardium
Lined with simple squamous epithelium
Is continuous with endothelium which lines blood vessels
Pericardium
Parietal Layer
In the middle, adheres to inner surface of fibrous layer
Simple squamous serous membrane
Visceral Layer
Directly covers the heart wall
Simple squamous serous membrane
Fibrous Layer
Most superficial
Dense irregular connective tissue which anchors heart to thoracic cavity
Pericardial cavity
Serous membranes secrete serous fluid into the space between the layers to maintain a frictionless environment as the heart beats
Coronary Vessels
Arteries
Left coronary artery
Circumflex artery
Anterior interventricular artery
Right coronary artery
Right marginal artery
Posterior interventricular artery
Coronary arteries are the first branches of the aorta
Veins
Coronary sinus
Middle cardiac vein
Small cardiac vein
Great cardiac vein
Drains straight into right atrium
Valves
Semilunar Valves
Pulmonary Semilunar Valve
located between the right ventricle and the pulmonary trunk
Aortic Semilunar Valve
Located between the left ventricle and the aorta
Atrioventricular valves
Right AV valve (Tricuspid)
Located between right atrium and right ventricle
Left AV valve (Bicuspid)
Located between left atrium and left ventricle
Supported by papillary muscles with chord tendineae
Function
Prevent back flow of blood within heart
Location
The heart is located posterior to the sternum just left of the midline between the lungs
Pathway of blood through the heart
Double pump
The heart has two ventricles that pump at the same time
The blood pressure has to be small going through lungs then it returns to heart to be pumped throughout the body
Pulmonary and systemic circulation
Starting in the body, blood goes next through
Superior Vena Cava/Inferior Vena Cava (and coronary sinus)
Right Atrium
Tricuspid Valve
Right Ventricle
Pulmonary semilunar valve
1 more item...
Arteries
Aorta
Branchiocephalic
Right subclavian
Right common carotid
Left common carotid
Left subclavian
Pumps oxygen rich blood systemically
Coronary Arteries
Pump oxygen rich blood to heart walls
Pulmonary Trunk
Pulmonary Arteries
Carry oxygen poor blood to lungs
Pumps oxygen poor blood to pulmonary arteries
Veins
Superior Vena Cava
Drain oxygen poor blood from superior portion of body into right atrium
Coronary Sinus
Drains oxygen poor blood from coronary vessels
Inferior Vena Cava
Drains oxygen poor blood from inferior portion of blood into right atrium
Pulmonary Veins
Carry oxygen rich blood from lungs to left atrium