Bio 20 Unit D3 Circulation & Immunity

What are the roles of the circulatory system

1. Transport gases, nutrients, and wste materials throughout the body.

2. Regulates internal temperature and distrributtion of hormones

3. Protects the body against disease

Components of the circulatory system

The Heart, Blood, and Blood Vessels

Step 1 of Blood Flow through the body

Body/Brain recives oxygenated blood from heart. Performs cell respiration and releases CO2 into bloodstream.

Step 2 of Blood flow through the body

Newly deoxygenated blood from the budy/Brain returns to the Heart.

Step 3 of blood flow through the body

Heart pumps the deoxygenated blood to the lungs, where CO2 is exchanged for O2

Step 4 of blood flowthrough the body

Newly oxygenated blood returns to the heart which pumps it out to he body/brain

Three main pathways of the circulatory system

Pulmonary, Systemic, and Coronary

Pulmonary Pathway

Circulates blood from the heart to the lungs and back

Systemic Pathway

Circulated blood from the heart to the body and back

Coronary Pathway

Circulated blood from the inside of the heart to the structure of the heart.

The heart is a muscular organ that

Pumps to circulate blood throughout the body.

The heart consists of two parallel pumps that are separated by the

Septum

How is the hearts pumping action synchronized

Immediately after the top of the heart contracts the bottom of the heart will contract.

Step 1 of the pulmonary pathway

After the body tissues have absorbed oxygen from the blood and deposited carbon dioxide from cellular respiration the blood travels to the heart

Step 2 of the pulmonary pathway

The pump on the right side of the heart receives deoxygenated blood from the body tissues and pumps it into the lungs (Alveoli)

Step 3 of the pulmonary pathway

The alveoli deposits oxygen into the blood and CO2 from the blood filters into the aveoli to be breathed out

Step 4 of the pulmonary pathway

The oxygenated blood is then pumped back into the heart

Step 1 of the systemic pathway

The left side of the heart receives the newly oxygented blood and pumps the blood towards the brain and body

Step 2 of the systemic pathway

The oxygen in the blood will be used for cellular respiration

Step 1 of the coronary pathway

Oxygen and nutrients are delivered to the heart through capillaries embedded directly in the heart wall

Step 2 of the coronary pathway

These capillaries are supplied by two small arteries that branch off of the aorta

Step 3 of the coronary pathway

Deoxygenated blood is carried away in coronary veins

The heart is composed of 4 chambers

Two atria (top chambers left and right), Two ventricles (bottom chambers right and left)

blood is carried to the heart by

Veins

The superior vena cava carries

deoxygenated blood from the head and upper body to the right atrium

The inferior vena cava carries

deoxygenated from all veins below the diaphram to the same atrium

How does oxygenated blood flowing from the lungs enter the left artium

By way of the pulmonary veins

The pulmonary arteries carry

deoxygenated blood (from the right ventricle to the lungs)

The pulmonary veins carry

oxygenated blood (from the lungs to the left atrium)

An artery is any blood vessel that carries blood ____ from the heart

AWAY

Veins are any blood vessel that carries blood ____ the heart

TOWARDS

The aorta is the largest

Artery in your body

The aorta carries

Oxygenated blood away from the heart

The coronary arteries are arteries that form an I portants branch of the

Aorta

The coronary arteries supply the muscle cells of the heart with

oxygen and nutrients

what do the valves called atrioventricular (AV) valves do

Seperate the atria from the ventricles

Av valves prevent

the flow of blood from the ventricles back into the atria

The AV valves are supported by bands of connective tissue called

Chordae tendinae

what do the semilunar valves seperate

The ventricles from the arteries

What is the shape of the semilunar valves

A half-moon shape (semilunar like the moon)

Semilunar valves prevent blood that has entered the arteries from flowing

Back into the ventricles

What does the septum prevent

oxygenated blood from mixing with deoxygenated blood

The muscle that surrounds the the ___ ventricle is much ___ than the muscle that surround the ___ ventricle

LEFT, THICKER, RIGHT

The left ventricle muscle is thicker than the right ventricle because

its responsible for pumping blood out to the entire body

the right ventricle only pumps blood

Out to the lungs

Chest pain or Angina occurs when

to liitle oxygen reaches the heart possibly by blocked arteries

The heart unlike other organs that slow down when they cannot receive enough nutrients must

continue to beat no matter what demands are placed on it

its estimated that the heart may use __ of the body’s total blood oxygen during times of stress

20%

the cardiac muscle displays two patterns called

Striated pattern and branching pattern

The hearts tempo or beat rate is set by the

Sinoatrial (SA) node

The SA node is located in the

upper right atrium

originating contractions in the atria travel to a second node called the

atrioventricular node (AV) node

The AV node serves as a

conductor that passes nerve impulses by two large nerve fibers (purkenjie fibres)

the purkinjie fibres carry

impulses from the AV node to the bottom tip of the heart

The left and right atria contract prior to the

right and left ventricle

heart rate is influenced by

autonomic nerves

what are the two regulatory nervous systems conduct impulses from the brain to the SA node

Sympathetic and parasympathetic nervous systems

During times of stress the sympathetic nerves increase

Heart rate

What happens to cause tachycardia

The heart exceeds 100 beats per minute

Tachycardia is caused by

Excercise, drugs (caffeine or nicotine)

During times of relaxation parasympathetic nerves are stimulated to

Slow Down the heart rate

The lubb-dubb sounds of our heart are caused by

Closing of the heart valves

The period of relaxation of the heart is called

Diastole

the periods of heart contractions are called

Systole

When valves do not close properly this causes

A heart murmur

An electrocardiogram (ECG) can be used to record

the electrical activity of the heart

On a ECG machine P represents

contraction of artria

On a ECG machine QRS represents

Contraction of ventricles

On a ECG machine T represents

recovery of ventricles

Ateries Carry

Blood away from the heart and is oxygenated blood

Arteries are composed of three layers

Outer and Inner which are connective tissues, while the middle layers are made up of muscle fibres

Blood from the arteries passes into smaller arteries called

Arterioles which eventually narrow into capillaries

Vasoconstriction

A nerve impulse causes smooth muscle in the arterioles to contract reducing diameter of the blood vessel.

Vasodilation

Relaxation of the smooth muscles causes dilation of the arterioles and blood flow increases

Capilaries connect

Arteries and veins to tissues

Capillaries are composed of

A single layer of cells (so small that red blood cells travel single file)

Capillaries Do not have ___ muscle tissue

Smooth

capillaries are the site of exchanging

Fluid and gas in the circulatory system

Cappillaries wiodej as they go towards the heart and eventually become

venules which merge together to form veins

the diameter of vein ____ as they approach the heart

Increase

veins contain valves that only open

one way

Skeletal muscle aid in

Venous blood flow

Venous pressure increases when skeletal muscles

Contract and push against the vein

Varicose occurs in veins when

leaflets of valves become damaged and fail to close properly causing blood to flow backwards

Blood pressure is

the pressure exerted against walls of the heart as blood is transported throughout the body

Blood pressure is measured by a ratio of

systolic and diastolic

Systolic pressure

maximum pressure during ventricular contraction

Diastolic pressure

Minimum pressure before ventricular contraction

Cardiac output

The amount of blood pumped by the heart

When do we have a greater stroke volume

The stronger the heart contractions

what are some variable that effect heart rate

lifestyle, anxiety, caffeine, temperature, illness, music, and dehydration

Arteriosclerosis

Hardening of the arteries due to a buildup of plaque

Arteriosclerosis Causes

lack of excessive, smoking, and diet of high fat

Arteriosclerosis symptoms

Chest pain (Angina), blood clots, shortness of breath, and heart failure

Treatments of arteriosclerosis

Apirin, Angioplasty, Coronary bypass

Congenital Heart Defects

Structural defects present from birth may be genetic or due to alcohol or drug use during pregnancy)

Common heart attack symptoms

Shortness of breath, Intense chest pain down to arms, cold sweat, and pain in left arm

What heart attack symptom is only in women

Neasea/vomiting, lightheadedness and unusual fatigue

Blood is half composed of fluid known as

plasma

Erythorcytes

red blood cells