Chapter 11The Circulatory System

Group 5Toñacao, Christine

Castillo, Melecia MeganCal, Kesler

Calustre, Reian

Circulatory System

• “The flow of nutrients, other elements and water into living organisms which are needed for growth and reproduction.”

• 3 major structures of this system:a. Heart

b. Blood Vessels

c. Blood

• 2 major circuit pathways:a. Pulmonary pathway

b. Systemic pathway

CirculationTwo Kinds of Circulatory System:1. Open Circulatory System2. Close Circulatory System

KINDS OF CIRCULATORY SYSTEM1. OPEN CIRCULATORY SYSTEM (insects and other invertebrates)

- blood does not remain in the vessels but instead is pumped from the heart into that open directly into tissue

- OSTIA (openings in heart) is present

- common to molluscs and arthropods

(evolved in crustaceans, insects, mollusks

and other invertebrates)

KINDS OF CIRCULATORY SYSTEM2. CLOSE CIRCULATORY SYSTEM

- blood remains within the vessels throughout its entire circuit

- Ostia is ABSENT

THE HUMAN CIRCULATORY SYSTEM

1. Cardiovascular System2. Lymphatic Vascular System

HUMAN CIRCULATORY SYSTEM

1. CARDIOVASCULAR SYSTEM

- composed of the blood vessels, the blood and the heart

2. LYMPHATIC VASCULAR SYSTEM

- composed of lymph capillaries, lymph vessels and collecting ducts.

BLOOD VESSELSVEINS, ARTERIES & CAPILLARIES

Blood Vessels

Blood Vessels1. Veins

- carries unoxygentatedblood containing picked up from body cells towards the heart.

- flow of blood is slow and smooth

- walls are thin, don't have much smooth muscle; readily distended when internal pressure is high

Venules- refers to the smallest veins

- walls are only a little thicker than those of capillaries

- both veins and venulesserve as temporary reservoir for blood volume; highly distensible

- blood volume is high in these vessels when the body's metabolic activity increases

- 50% of total blood volume; found in veins

- prolonged compression of the superficial veins in the legs can contribute varicose veins

Blood Vessels2. Arteries- carries oxygenated blood away

from the heart where the flow of blood is pulsating or in spurts.

- walls are thick and deeply set with impermeable walls containing smooth muscles and distensible tissues.

- composed of three outer and inner layers that are primarily connective tissues

- middle layer; made up of muscle fibers and elastic connective tissue

- smallest arteries is called arterioles

CONDITIONS

Aneurism

- a birth defect or injury can cause the inner wall of the artery to bulge

Stroke

- a weakened

artery in the brain

Three kinds of Arteries1. ELASTIC ARTERIES- large arteries leading directly

from the heart; also called conducting arteries.

2. MUSCULAR ARTERIES- medium sized with middle coats

that are chiefly muscular; also called distributing arteries.

3. ARTERIOLES- smallest arteries connected to

the capillaries that reduce pressure of blood before reaching the capillaries.

Blood Vessels3. CAPILLARIES - smallest blood vessels supplying blood to the

organs and tissues.- an endothelial tubes that connect arteries and

veins

KINDS OF CAPILLARIES 1. CONTINUOUS CAPILLARIES- found in muscles connective tissues and

central nervous system2. FENESTRATED CAPILLARIES- found in the renal glomeruli, endocrine glands

and intestine3. SINUSOIDS- the enlarged capillaries found in the liver, spleen

and bone marrow- these vessels are so narrow that red blood cells

pass through them in single line.- the thin walls of capillaries allow the exchange of

dissolved nutrients, wastes, oxygen and other substances between blood and cells.

- capillary beds are easily destroyed- high blood pressure can rapture the thin layered

capillaries

CONTINUOUS FENESTRATED

SINUSOIDS

Blood Vessels

The Heart• A large, four-chambered muscular organ

(involuntary muscle)• Location: slightly to the left of the middle

of the chest cavity• Function: The right side of

the heart maintains pulmonary circulation to the nearby lungs while the left side of the heart pumps blood all the way to the extremities of the body in the systemic circulatory loop. The heart functions by pumping blood both to the lungs and to the systems of the body.

• No larger than the size of your fist• Mass: about 300 grams• 70 beats per minute• (2.5 billion times in 70 years life span)• Pumps blood enough to fill 2 large ocean

tankers

Parts of the Heart

Parts of the Heart

Parts of the HeartATRIOVENTRICULAR VALVES (AV Valves) tricuspid valve (right) bicuspid/mitral valve (left)

SEMILUNAR VALVES(SV Valves) pulmonary artery aortic (semilunar) valve

Function:These flap-like valves control the direction of the blood flow inside the heart (prevent it to flow back)

The Cardiac Cycle• sequence of muscle contractions and relaxation in the heart•Two main pumping actions of the heart:a. Diastole - relaxationb. Systole – contraction

•Lub sound – closing of the atrioventricular valve (AV)•Dub sound – closure of the semilunar valve (SV)• 72 contractions / min (forces 80 ml of blood into the aorta)• Stroke Volume – amount of blood passing through the heart with each heartbeat•Cardiac Volume – amount of blood pumped from the heart each minute (5-6 liters)

The Cardiac CycleRight side of the heart (PULMONARY)1. Blood enters the heart IVC and SVC,

emptying oxygen poor blood from the body into the RA.

2. As the atrium contracts, blood flows from your RA into your RV through the open tricuspid valve.

3. When the ventricle is full, the tricuspid valve shuts. This prevents blood from flowing backward into the right atrium while the ventricle contracts.

4. As the ventricle contracts, blood leaves the heart through the pulmonary valve, into the pulmonary artery and to the lungs, where it is oxygenated. The oxygenated blood then returns to the heart through the pulmonary veins.

1

2

The Cardiac CycleLeft side of the heart (Systematic)1. The pulmonary veins empty

oxygen-rich blood from the lungs into the left atrium.

2. As the atrium contracts, blood flows from your left atrium into your left ventricle through the open mitral valve.

3. When the ventricle is full, the mitral valve shuts. This prevents blood from flowing backward into the atrium while the ventricle contracts.

4. As the ventricle contracts, blood leaves the heart through the aortic valve, into the aorta and to the body.

3

4

Two Major Pathways

Heart Conduction System a group of specialized cardiac muscle

cells in the walls of the heart that send signals to the heart muscle causing it to contract

The main components of the cardiac conduction system are the SA node, AV node, bundle of His, bundle branches, and Purkinje fibers.

Heart Conduction SystemSinoatrial Node (SV node)- Aka Cardiac Pacemaker- a small group of specialized muscle in the wall of the RA - Influenced by the autonomic nerves ( these nerves regulates the

rate of heartbeat; impulses from the vagus nerve slow the pacemaker)

Atrioventricular Node (AV node)- Impulses reaches the AV node near the ventricles- Triggers an impulse that causes the ventricles to contract

Bundle of His- it transmits impulses from the atrioventricular node, located at the

inferior end of the interventricular septum, to the ventricles of the heart.

Purkinje Fibers- Where the signals from the left and right branches pass through- Connected to the walls of the ventricles

Heart Conduction System

Heart Conduction SystemECG machine

- An electrocardiogram (EKG or ECG) is a test that checks for problems with the electrical activity of your heart. An EKG shows the heart's electrical activity as line tracings on paper. The spikes and dips in the tracings are called waves. The heart is a muscular pump made up of four chambers

Heart ConditionArrhythmia or Dysrhythmia *wrong spelling sa book

- a disorder of the heart rate (pulse) or heart rhythm. The heart can beat too fast (tachycardia), too slow (bradycardia)

- “Bad rhythm” in Greek and usually occurs in the upper chamber of the heart, called the atria

Regulation of Blood Pressure and Flow of Blood• Blood Pressure (BP)- The force against the arterial walls that moves

blood from the heart through the body

- Generated by heart contractions to keep blood circulating

- Blood always flow from high to low pressure

- Blood flowing through the pulmonary and systematic circulation

- BP is commonly measured in the brachial arterywith a device known as sphygmomanometer

- Normal BP in adult is 120/80 mm hg

- BP ↑ during exercise and times of stress

- High blood pressure or hypertension is a medical condition and the cause of high BP is arteriosclerosis (hardening of the arteries: accumulation of cholesterol or fatty materials around the walls of arteries → narrow and walls are rigid → pressure increases →if untreated = stroke/heart attack)

Examples of Blood Clot

Cerebrovascular accident. The picture above shows a portion of the brain that has been compromised due to lack of blood supply. This patient has a stroke because in this case, the blood flow to the brain was stopped because the vessel was occluded by a clot.

Blood Cells1. RBC2. WBC3. Platelets

Differences between RBC, WBC & Platelet

THE CLOTTING PROCESSPlatelets, Thromboplastin, Fibrin

The Clotting Process

• Aka Blood Coagulation

• an important process that prevents excessive bleeding when a blood vessel is injured.

• Platelets (a type of blood cell) and proteins in your plasma (the liquid part of blood) work together to stop the bleeding by forming a clot over the injury.

• The expected range for clotting time 4 – 10 mins

Blood Type• Four types: O, A, B and AB

• Variation are due to two antigens on the surface of the red cells, symbolized as A and B

• Antigens are proteins that increase the manufacture of the anti-body (one or two other types of proteins found in the blood plasma; Anti-A and Anti-B)

• Blood Type O are universal donors because they have no antigens

• Blood Type AB are universal recipients because of having no antibodies in the plasma

Blood Clot illustration

Examples of Blood Clot

Venous thrombus. A blood clot (thrombus) that forms within the vein. The picturesabove is a condition called deep vein thrombosis (DVT) or sa bisaya “Barikos”. Thereis blood clot in the deep veins of the leg.

The Lymphatic SystemPrincipal Functions:

collects and transports fluid from the intercellular spaces of the tissues and returns it to the blood by way of lymph vessels, immune mechanism and the lymph system absorbs fats from the villi of the interstitial tract and transports them to the bloodstream

Consists of: Lymph

Lymphocytes

Lymphatic Vessels

Lymph Nodes

Tonsils

Spleen

Thymus

The Lymphatic System• The system of vessels that connects with the

veins of the cardiovascular system• Transports lymph (colorless interstitial fluid of

the blood) – a watery solution does not contain RBC which remain in the closed circulatory loop because they are too large to pass through the capillary membranes

• before, it is the plasma in the blood, but if its in the lymphatic circulation it is called lymph, leaving the red blood behind

• Tonsils, Thymus and Spleen are like lymph nodes, they produce lymphocytes (similar to wbc for immune)

• Lymphocytes release the macrophage (large cells that engulfs target cells) or activate general immune system when they encounter foreign invaders or bacteria/virus

The Lymphatic System consists of:

Lymph Capillaries

- Have no openings but is permeable to

all substances dissolved in the interstitial fluid

Collecting Ducts

- drains into veins in the lower back

Lymph Vessels- open-ended vessels (has valves)- drain the lymph from around the

cells to the lymphatic trunks and ducts and, eventually, to the subclavian veins.

Lymphoid Organs1. Lymph Nodes

- are small, bean-shaped glands throughout the body. They are part of the lymph system, which carries fluid (lymph fluid), nutrients, and waste material between the body tissues and the bloodstream.

2. Spleen- largest organ of lymphatic system- Oblong and flattened shape and darkish purple color- located below the diaphragm- in the spleen, the lymphoid tissue filters out bacteria and worn-out blood cells from the blood

3. Thymus gland- located in the mediastinum behind the sternum- Age 25: decrease size and old age: diminish/disappear entirely

Lymphoid Organs

4. Tonsil- masses of lymphoid tissues embedded in mucous membrane- disk-like shape and become smaller during puberty

5. Patches of lymphoid tissues in the small intestine- The lymph nodes that become inflamed are in a membrane that attaches the intestine to the abdominal wall. These lymph nodes are among the hundreds that help your body fight disease. They trap and destroy microscopic "invaders" like viruses or bacteria. Mesenteric lymphadenitis often causes abdominal pain.

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