circulatory system

for bio-1

what are the key parts of the circulatory system?

1. HEART <3 (Muscular pump, circulates blood)

2. BLOOD VESSELS ( system if closed tubes used to transport blood)

3. BLOOD

Pericardium

a fluid filled membrane/sac that surrounds the heart,n holds it in place

Blood is carried AWAY from your heart by

ARTERIES

Aorta:

LARGEST ARTERY in your body.

what does the AORTA do?

Carries blood from the the LEFT ventricle to the rest of the body

Superior Vena Cava

Large vein that collects bloods from other veins in the head and arm…

where does the SUPERIOR vena CAVA transport blood?

transports it to the RIGHT ATRIUM

Inferior vena cava

 large vein that collects blood from veins in the trunk and legs

where does the INFERIOR VENA CAVA transport blood to?

RUGHT ATRIUM

Right atrium

upper right chamber that collects deoxygenated blood from the 2 vena cava

where does the RIGHT ATRIUM push blood to?

contracts to force blood into right ventricle

Left atrium

Upper left chamber that collects oxygenated blood from PULMONARY VEIN.

where does the left atrium push blood to?

contracts to force blood into left ventricle

where does the LEFT atrium get oxygenated blood from?

PULMONARY VEIN

Right ventricle

big muscular chamber that contracts to push blood into pulmonary artery

Left ventricle

LARGEST heavily muscled chamber contracts to force blood into aorta to rest of body

Right AV valve/ Tricuspid valve:

3 flapped valve that closes to prevent backflow of blood into the right atrium while right ventricle contracts

Left AV valve/ Bicuspid Valve:

2 flapped valve that closes to prevent blood backflow of blood into left atrium while left ventricle contracts

what do the atrioventricular ( AV) valves do?

ensures one directional flow by preventing backflow of blood

Pulmonary artery

Carries deoxygenated blood from RIGHT VENTRICLE to the lungs

Pulmonary Vein

carries oxygenated blood from lungs to LEFT ATRIUM

Coronary arteries

arteries that branch off the aorta to provide oxygenated blood to the heart tissue

Pulmonary semilunar valve

at the mouth of the pulmonary artery. Prevents backflow of blood into RIGHT ventricle

Aortic semilunar valve:

 at mouth of aorta. Prevents backflow of blood into LEFT ventricle

what are the three circuits that make up the circulatory system?

1. pulmonary

2. systemic

3. cardiac

pulmonary circuit

Vessels that carry blood from HEART TO LUNGS and back

systemic circuit

Vessels that carry blood from the HEART TO BODY and back

cardiac circuit:

Branches off the aorta ( cardiac arteries) to supply blood to the heart and return to the vena cava

what are the three types of BLOOD VESSELS?

1. arteries and arterioles

2. capillaries

3. veins and venules

what are arterioles

smaller arteries

what’s pulse?

change in the diameter of arteries following heart contractions

Vasoconstriction

NARROWING of vessel diameter (less blood delivered to tissues)

Vasodilation:

WIDENING of vessel diameter more blood delivered to tissues)

when do arterioles leading to capillaries open?

when the cells in that area need blood

what do capillary sphincters do?

regulate the movement of blood from arterioles into capillaries

capillaries

site of fluid and gas exchange between the blood and the cells

Tiny blood vessels where food, oxygen and wastes are exchanged with the cells of the body

SO SMALL THE CELLS HAVE TO PASS SINGLE FILE

what do the capilliaries allow

EASY DIFFUSION of substances TO AND FROM BLOOD

veins:

 blood vessels that carry blood toward the heart.

venules

 small veins.

what do venules do?

hey receive blood from the capillaries and then pass that blood along to the larger veins.

how does blood get back to the heart?

Veins carry blood towards the heart

Blood through veins have low pressure so veins have valves to prevent backflow

MUSCLE CONTRACTION helps to circulate the blood! ( downsides: fainting after standing, varicose veins)\

• vein pressure increase when skeletal muscles contract

• the muscles bulge and reduce veins diameter

• pressure increase=valves open and allow flow to heart

how do varicose veins form

when the vein valves break then gravity causes the blood to flow and pool downward towards the feet. it causes the surface of the veins to bulge andc causes varicose veins

Diastole

the period of relaxation. Part of the heart cycle when heart is relaxed

Systole:

 the part of the cycle where the heart contracts to push blood through its chambers

Cardiac cycle event : list events (3)

Atrial and ventricular diastole

Atrial systole, ventricular diastole:

Ventricular systole atrial diastole

1. Atrial and ventricular diastole

1.  relaxation phase where they're diastole. Blood from vena cava flows to atria and ventricles.  (av valves open)

2. Atrial systole, ventricular diastole:

atrium contracts to force blood into ventricles

3. Ventricular systole atrial diastole

Ventricle contracts and pumps blood to pulmonary arteries and aorta

Sinoatrial Node ( SA node): what does it do

 sets the hearts tempo/beat rate

 What is the SA node?

Specialized bundle of nerves. They act as a PACEMAKER for the heart

how does the SA node work?

• The NERVOUS system signals  the heart and causes the pacemaker to increase or decrease the heart rate

Impulse transmission:

1. SA NODE CONTRACTS

2. AV NODE

3. bundle of his

4. Purkinje fibers:

explain impulse transmission/Nervous control of the heart:

1. Pacemaker makes a wave of signals ( contracts)

2. Signals spread through both atria ( makes them contract)

3. Signal spreads through the  bundles of “his” and purkinje fibers to heart apex ( tip)

4. Signals spread through ventricles. Ventricles contract from apex towards atria and forces blood into large arteries.

Electrocardiogram ( ecg):

A recording of the electrical charges that occur in the myocardium during the cardiac cycle

parts of an ECG

1. p wave

2. QRS complex

3. T WAVE

P WAVE:

 represents electrical impulse tht causes atrial contraction

QRS complex:

represents the electrical impulses that causes ventricular contraction

T wave:

signals the ventricles have recovered

explain lub dub sounds

Lub: av valves closing during contraction (systole)

DUB= semi lunar valves closing during relaxation ( diastole)

PULSE RATE:

pulse is measured in….

Beat per minute

what is Blood pressure measured using?

• Measured through a stethoscope and sphygmomanometer

BP measures TWO LEVELS: (explain what happens in the heart in these levels)

1. SYSTOLE: pressure during ventricular contraction (pushes blood through)

2. DIASTOLE: pressure as the heart refills  ( relaxing state)

Where is the pressure most highest in body?

• Blood pressure drops from highest arteries to low veins

what is blood pressure measured in?

• BP measured in mm of Mercury ( Hg)

Factors that affect blood pressure:

Cardiac output ( blood volume and heart rate)

Arteriolar resistance

Baroreceptor cells: 

• Cells found in walls of the large arteries ( aorta and carotid) are very sensitive to blood pressure

what do Baroreceptor cells do ( when bp is high? Low?)

• They send nerve impulses to medulla oblongata of the brain

• When bp is high brain sends signal to nerve impulses to reduce heart rate and dilate arteries ( bp decreases)

• When bp is low, brain sends impulses to increase heart rate, and constrict arteries ( increases blood pressure)

what’s Hypertension:

high blood pressure.

what happens over long period with hypertension?

• vessels weaken and may rupture

• Body tries to fix by building up support= vessels harden and bp becomes higher during systole

• Symptoms not noticeable. First sign is heart attack stroke.

name Some things blood does: 

1. Carries nutrients and 02 to cells, removes wastes carries to disposal organs, maintain body temp, fight infections, closes wounds

4 MAIN PARTS OF BLOOD

1. red blood cell ( ( erythrocytes):

2. white blood cells

3. platelets

4. plasma

red blood cells ( ( erythrocytes):

• small cells that cary o2 using hemoglobin

• Have NO nucleus 

• Produced in the bone marrow

• Carbon monoxide binds tightly to hemoglobin→ asphyxiation

asphyxiation

• Carbon monoxide binds tightly to hemoglobin

White blood cells ( leukocytes)

• Infection fighting cells that eat invaders

• Amoeboid shape

Platelets (thrombocytes)

• Tiny cell fragments involved in blood clotting

• Sare sticky when exposed to o2

• Ppl who lack platelets have hemophilia ( they will bleed to death from tiny cuts.)

Plasma:

• Liquid part of blood that carries  water nuitrients, co2, waste and antibodies

Atherosclerosis - 

a disease where fatty substances, cholesterol, cellular waste products, calcium and other substances deposit in the arterial wall. 

Aneurysm: ( go into depth later pls)

a weakening of an artery wall

Function of lymphatic system:

• Bodys “ sewerage system”

• Maintains  fluid levels in our body tissue by removing all fluids that leak out of blood vessels

• Important for optimal function of immune responses

How lymphatic system works:

1. Fluid enters by diffusing into tiny lymph capillaries that are intermingled among blood capillaries

2. Once inside lymphatic system, fluid is called “lymph”. The system drains it into the circulatory system

3. Rhythmic contractions of lymph vessels help draw fluid into lymph capillaries

4. Lymph vessels depend on one-way valves and skeletal muscle contractions to move lymph fluid toward the heart.

5. Lymphatic vessels drain into collecting ducts which empty their contents into the two subclavian veins. ( under the collarbone) these veins join to form the superior vena cava and large vein that draws blood from upper body into heart

LYMPH NODES:

• small organs found along the length of the lymph vessels.

what do lymph nodes do?

• Site of proliferation( rapid increase in numbers.) of an immune cell called lymphocytes

• When body fights an infection, lymphocytes multiply rapidly. ( this accounts for swelling and tenderness in lymph nodes.