Heart

Circulatory System

Pulmonary Arteries – transport blood to lungs
Pulmonary Veins – transport oxygenated blood to heart
Aortic arch and trunk – main arteries from the heart
Common carotid artery – carries blood to brain
Renal vein and artery – connected to kidneys
Mesenteric Veins – connects to intestines

Arteries – away from heart ( A – AWAY)
Views – back to heart (deoxygenized)

Pulmonary circulation – move btw heart and lungs
Systemic circulation – moves blood btw heart and rest of the body

The Heart

Aorta – major artery of the systematic circulation, carries oxygen rich blood from the LEFT ventricle to all parts of the body

Coronary Arteries – supply heart itself

Superior Vena Cava – drains UPPER body
Inferior Vena Cava – drains LOWER body

Atrium – 2 parts (causes no blood to mix)
Right – deoxygenated blood from systematic circulation
Left – oxygenated blood from the lungs


Heart Values (2 pairs)
1. ATRIOVENTRICULAR (AV value)
a. Guards the openings btw atria and ventricles
i. Right side - TRICUSPID VALUE
ii. Left side – BICUSPID,(aka) MITRAL VALVE
2. SEMILUNAR VALUES – out of the artery system
a. Right – PULMONARY VALUE
b. Left – AORTIC VALUE

AUTONOMIC NERVOUS SYSTEM
Diastole – relaxing state
Systole – slight delayed relaxing state (contracted)
BLOOD PRESSURE (sphygmomanometer) – SYSTOLIC / DIASTOLIC ratio

Pulmonary Arteries – deoxygenated blood from the right ventricle to the R and L lungs
Pulmonary Veins – return rich oxygenated blood from the lungs to the left atrium.

Contraction of the Heart

Stimulated by membrane depolarization
Caused by SA NODE (sinoatrial node)***most important autorthymic fibers**

Autorthymic fibers – SA NODE ( sinoartial node) located in the right atrium, acts as the PACEMAKER for the rest of the heart, SPONTANEOUS ACTION POTENTIALS faster than other cells, WITHOUT NEURAL ACTIVATION

ATRIOVENTRICULAR – AV NODE, depolarization travels quickly over both ventriles by a network of fibers called the ATRIOVENTRICULAR bundle, aka (BUNDLE OF HIS)---information then relayed to PURKINJE FIBERS

PURKINJE FIBERS – directly stimulate the myocardial cells of the left and right ventricles causing the contraction

Blood Vessels

Arterioles – finest, microscopic branches of the arterial tree

Capillaries – blood from arterioles
Venules – blood is collected which leads to large vessesls *VEINS (back to heart)

Arteries & Veins – MADE UP OF:
**Endothemlium, Elastic Fibers, Smooth Muscle, Connective Tissue**

Capillaries – MADE UP OF:
One layer of endothemlium – allows rapid exchange of gases and metabolites btw blood and body cells

Arteries and arterioles- MADE UP OF:
Smooth muscle layer resulting in VASOCONSTRICTION, which increases resistance and decreases blood flow (hypertension and blood pressure)

***Vasoconstriction – contraction of smooth muscle layer, increased resistance and decrease flow
***Vasodilation – relaxing smooth muscle layer – decreasing resistance and increasing flow








Veins and Vensules – MADE UP OF:
Thinnest layer of smooth muscle (smoother muscle than arteries), work with skeletal muscles, ONE WAY contraction called VENOUS VALVES

Venous valves – moves blood one way

Lymphtatic System MADE UP OF:
Lymphatic capillaries, lymphatic vessels, lympth nodes, and lymphatic organs

Lymph – one way values, drains into subclavian veins

Lymph Nodes – contain GERMINAL CENTER (lymphocyte activation)

Heart Diseases

Heart Attack – MYOCARDIAL INFRACTION, lack of blood to heart, #1
Atherosclerosis – fatty material in the arteries
Arteriosclerosis – artery hard due to calcium deposition
Athersclerotic Lesions – many issues!!

Angina Pectoris – CHEST PAIN

Stroke – interference with blood supply to BRAIN

Blood Pressure / Flow

AUTONOMIC NERVES SYSTEM
Medulla Oblongata – controls Heart Rate
Norepinephrine - SYMPATHETIC neurons, **increase heart rate
Acetylcholine – PARASYMPATHERTIC neurons, **decrease heart rate

Baroreceptor Reflex – NEGATIVE feed back loop that controls response to changes in blood pressure , detect change in arterial blood pressure
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Blood Volume is regulated by 4 HORMONES (Blood pressure goes with blood volume)
ANTIDIURETIC HORMONES (ADH)
ALDOSTERONE
ATRIAL NATRIURETIC HORMONE
NITRIC OXIDE (NO)

Cardiac Output – volume of blood pumped by each ventricle per min

BP=CO x R
Blood pressure = (cardiac output)(resistance to blood flow)
Blood

Connective tissue, contains plasma, formed elements

Functions –
Transportation - materials (vitamins)
Regulation – body functions (urine)
Protection – injury (white blood cells, protects)

Plasma – made up of 92% WATER…also contains….

1. Nuterients, wastes, hormones
2. Ions
3. Proteins
a. Albumin- (alpha and beta globulins)
b. Fibrinogen -(if removed, called SERUM)
4. Red blood cells – ERYTHROCYTES (about 5 millon per MCL)
a. Hematocrit –fraction of the total blood volume occupied by red blood cells
5. Hemoglobin – pigment that binds and transport oxygen
6. White Blood Cells (leukocytes)
a. Less than 1% of blood
i. Larger than erythrocytes
ii. Can migrate out of capillaries
iii. GRANULAR – neutrophils, eosinophils, and baso phils
iv. ANGRANULAR – monocytes and lumphocytes

7. Platelets – pinch off from larger cells in bone marrow, blood clots


**ALL the formed elements of blood comes from PLURIPTENT STEM CELLS**

HEMOGLOBIN -
Effected by pH and temp (BOHR SHIFT)
Causes H+ bind to hemoglobin
4 polypeptide chains (2 alpha helix and 2 B)
HEME – central iron atom that can bind to O2
OXYHEMOGLOBIN – loaded with O2, some molecules lose O2 causing DEOXYHEMGLOBIN

8% - of CO2 is dissolved in plasma
20% - bound to hemoglobin
72% - diffuse into red blood cells
CARBONIC ANHYDRASE (CO2 & H20= forms H2CO3)



Respiration

*works with the cardiovascular system to exchange gases btw the air and blood (external respiration) and btw blood tissue and fluid (internal respiration) * cellular respiration is the final destination where ATP is produced.

Fick’s law of diffusion – rate of diffusion btw two regions

R=DA(PIE)P / d

Gas Exchange – driven by differences in partial pressures GRADIENTS OF O2 AND CO2, ventilation perfusion mismatch

ALVEOLI – sites of gas exchange – surrounded by lots of capillaries, MILLIONS,

AIR –
1. Larynx – inhaled air passes through first then…Glottis, and trachea
2. Right and Left BRONCHI
3. BRONCHILOES – surround by capillary network

Tidal Volume – at rest
Vital capacity – max air expired
Hypoventilation – lack of breathing, HIGH PCO2 (partial pressure of co2)
Hyperventialation – excess breathing, LOW PCO2


Lungs- MEDULLA OBLONGATA **control center**
THORACIC CAVITY
Branched tubular passage, 2 way
Each covered with VISCERAL PLEURAL MEMBRANE
PARIETAL PLEURAL MEMBRANE –lungs INNER wall lined
PLEURAL CAVITY – SPACE BTW MEMBRANES
MEDULLA OBLONGATA – controls breathing
Neurons stop producing impulses , relaxed exhalation occure

NEURONS ARE SENSITIVE TO PARTIAL CHANGE IN CO2
More CO2, increases CARBONIC ACID, lowing pH
Chemosensitive Neurons
AROTIC
CAROTID BODIES

During inhalations two muscles contact
Intercostal Muscles- expand the rib cage
Diaphram- expands volume of thorax and lungs (NEGATIVE PRESSURE)

Elastic Tension- caused by breathing – Thorax , Lungs


EXPIRATION
Exhale
PASSIVE
Can become active
Uses internal intercostals and abdominal muscles
ELASTIC RECOIL
Alveoli stretch, STRETCH RECEPTORS than inhibit respiratory center

Air goes downward because of gravity
Partial Pressure????


INSPIRATION
Inhale
ACTIVE
Medulla Oblongata – causes rib cage to rise and diaphragm to lower, expansion
Negative Pressure – aka parial vacuum in alveoli causes air to come in
Increases CO+ and H+ in blood

ALVEOLAR MEMBERAN
SURFACTANT & WATER LAYER
Simple Squamous epithelium
Basement membrane of wall ??
Interstitial Space
Capillary Wall – simple SE
Basement membrane of cap wall

Pulmonary Ventilation – BREATHING, in and out of lungs, nasal breathing (cleans), PLEURAL SACS suspend the lungs from the thorax and contain fluid to prevent friction against thoracic cage , controlled by brain stem, sends impulses, CHEMORECEPORERS,

Pulmonary Diffusion – Oxygen rate a which it diffuses from alveoli into blood **OXYGEN DIFFUSION CAPACITY**
Trained – athletes, male, female?
**CARBON DIOXIDE’S MEMBRANE IS 20 TIMES GREATER THAN THAT OF OXYGEN, C02 DIFFUSES MORE QUICKLY**

GOAL OF RESPIRATION – maintain blood, tissue gases, pH to normal levels