Module 5: Cardiovascular and Muscle physiology

What is the cardiovascular system?

A closed system of the heart and blood vessels

What's another name for the cardiovascular system?

Circulatory system

What are the functions of the cardiovascular system?

-Transportation & waste removal

-Protection

-Regulation

What does the cardiovascular function protection entail?

-Inflammation

-Limit spread of infection

-Destroy microorganisms and cancer cells

-Neutralize toxins

-Initiate cloting

What does the cardiovascular function regulation entail?

-Fluid balance

-Stabilizes pH and ECF

-Temperature control

What does the cardiovascular function transportation & waste removal entail?

-O2

-CO2

-Nutrients

-Waste

-Hormones

What are the two primary divisions of the cardiovascular system?

-Pulmonary circuit

-Systemic circuit

What side of the heart is the pulmonary circuit on and what does it do?

Right side

-Carries blood to lungs for gas exchange and back to the heart

What side of the heart is the systemic circuit on and what does it do?

Left side

-Supplies oxygenated blod to all tissues of the body and returns it to the heart

What happens on the left side of the heart?

-Fully oxignated blood arrives from lungs via pulmonary veins

-Blood sent to all organs of the body via the aorta

What happens on the right side of the heart?

-Oxygen-poor blood arrives from inferior and superior vena cava

-Blood sent to lungs via the pulmonary trunk

What structure does blood arrive to the right side of the heart from?

-Inferior Vena Cava

-Superior Vena Cava

Through what structure is blood sent to the lungs?

Pulmonary trunk

Through what structure is blood sent to al organs?

The aorta

Where is the heart located?

Between the lungs

What is the base of the heart?

Top of the heart

-Wide, superior portion of the heart

-Large vessels are attached here

What is the Apex of the heart?

Bottom of the heart

-tapered inferior end

-Tilts to the left

What is the size of the heart dependent on?

Species!

-Similar proportion to body mass

What is the pericardium?

Double walled sac that encloses the heart

What does the pericardium do?

Allows heart to beat without friction

-Provides room to expand but resists excessive expansion

Where is the pericardium anchored to?

The diaphrage

T/F - the pericardium contains fluid

True

What are the pericardium layers?

1) Parietal pericardium

2) Visceral Pericardium

What is the parietal pericardium?

outermost layer of pericardium

-Fiberous layer of connective tissue

What is the visceral pericardium?

Innermost layer of pericardium

-Serous membrane covering the heart

What are the layers of the heart wall?

1) Epicardium

2) Myocardium

3) Endocardium

What is the epicardium?

Outermost layer of the heart wall

-Serous membrane covering heart

-Coronary blood cessels travel through this layer

What is the myocardium?

Middle layer of heart wall

-Layer of cardiac muscle spiraling around heart producing wringing motion

-Fiberous skeleton of heart

What does the myocardium provide for the heart?

-Structural support and attachments for the heart

-Electrical insulation between atria and ventricles

What is the endocardium?

Innermost layer of heart wall

-Smooth inner lining of heart and blood vessels

-Covers the valve surfaces and is continuous with endothelium of blood vessels

What are the chambers of the heart?

1) Right Atria

2) Left Atria

3) Right Ventricle

4) Left ventricle

What are the superior chambers of the heart?

-Right Atria

-Left Atria

What do the left and right atria do?

Receivs blood returning to the heart

-From body or from lungs

What are the inferior chambers of the heart

-Right ventricle

-Left ventricle

What do the left and right ventricles do?

Pump blood into artries

What do valves do within the heart?

Ensure one-way flow of blood through heart

What are the main two valves of the heart?

-Atrioventricular (AV) valves

-Semilunar valves

What do atrioventricular (AV) valves do?

Controls blood flow between atria and ventricles

WHat do semilunar valves do?

Controls flow into "great" arteries

-Pilmonary and aortic valves

What is the blood blow through the heart? (simplified)

Right atrium -> Pulmonary circuit -> systemic circuit (through body) -> back to starting point

What is the cardiac cycle?

Repeating patterns of contracting and relaxing of the heart

What is systole?

Contracting phase of heart

What does systole do?

Sends blood to the rest of the body

What is diastole?

Relaxation of the heart

What does diastole do?

Fills heart with blood

What is heart rate?

Number of times a heart beats per minute (bpm)

T/F -The heart rate is the same is every species

False

What influences heart rate?

-Body size

-Metabolic rate

-Activity level

-Emotional state

What is the average heart rate in adult humans?

60-100 bpm

What is the average heart rate in athletes?

40-60 bmp

What is the average heart rate in children/new borns?

100-160 bpm

What is blood pressure?

Force of circulating blood against the walls of arteries

T/F - Blood pressure is influences by species?

True

How is blood pressure measures?

Systolic/diastolic

What happens to blood pressure as it moves through the body?

Blood pressure dissipates as it moves through each branch of cardiovascular system

-BP is lower at feet than in the neck

How much blood is pumped into the heart?

5% of blood

What is coronary circulation?

the functional blood supply to the heart muscle itself

About how many mL of blood are pumped into the heart per minute?

~250 mL

Why does the heart pump so much blood into itself?

Needs a lot of O2 and nutrients

-It is a constantly moving muscle

How do heart attacks occur?

Blood flow to the heart muscle layer (mycardium) is blocked

What are some causes of heart attacks?

-Buildup of fatty deposits in coronary arteries

- Coronary artery spasam

-Other factors such as high BP, high cholesterol, smoking, diabetes and obesity

What are the three main types of blood vessels?

-Arteries

-Veins

-Capillaries

What direction do arteries carry blood?

Away from the heart

What direction do veins carry blood?

towards the heart

What do capillaries do?

Connect the arteries to veins

What are the layers of blood vessels

1) Tunica Interna

2) Tunica Media

3) Tunica Externa

What is the Tunica Interna?

Inner portion of the blood vessel

-Lines the blood vessel and is exposed to blood

-Lined with endothelium cells

-Acts as selectively permeable barrier

-Secretes chemicals that simulate dilation or constrction of vessel

What is the Tunica Media?

middle layer of blood vessel

-Made up of smooth muscle, collagen and elastic tissue

-Prevents vessel from repturing due to pressure

-Regulates diameter of blood vessel

What is the Tunica Externa?

Outermost layer of blood vessel

-Consists of loose connective tissue

-Anchors the blood vessel

What are capillaries?

Smallest blood vessels

-Site of exchange between gasses, nutrients, waste and hormones

Where are capillaries absent in the body

-Tendons

-Ligaments

-Epithelia

-Cornea

-Lens of the eye

What are the types of capillaries?

-Continuous

-Fenestrated

-Sinusoids

What are continuous capillaries?

Occurs in most tissues

-Contains intracellular clefts and pericytes

What do intracellular clefts in continuous capillaries do?

Allows passage of molecules into tissues

What do pericytes in continuous capillaries do?

Wraps around the capillaries and contains the same contractile proteins as muscle

What blood vessel layer role dose the pericyte provide?

Role of the tunica media

What are Fenestrated capillaries?

Cappilaries riddled with holes called filteration pores

-Allows for passage of only small molecules

-Occur in kidneys and small intestines

What are Sinusoids capillaries?

Irregular blood-filled spaces with large fenestrations

-Occurs in liver, bone marrow, and spleen

-Allows proteins, clotting factors and new blood cells to enter circulation

WHat are capillary beds

networks of 10-100 capillaries

-supplied by a single arteriole

-3/4 of the body's capillaries beds are closed at any given time

What are precapillary sphincters?

Controls blood flow within capillary bed

What happens when precapillary sphincters are relaxed?

Capillaries are well perfused with blood

What happens when precapillary sphincters are constricted?

Blood flow is constricted and blood bypasses capillaries

What are some key features of veins and venules?

-Greater capacity for blood containment

-Tinner walls

-Collapse when empty

-Steady blood flow

-relatively low blood pressure

What are the main circulatory routes?

-Simplest pathway

-Portal system

-Arteriovenous anastomosis

What is the circulatory route simplest pathway?

1 capillary bed

-Most common route for blood

-Passes through only one nerwork of capillaries from time it leaves heart until it returns

What is the circulatory route portal system?

2 capillary beds

-Two consecutive capillaru networks

-Between hypothalamus and anterior pituitary

-in kidneys and between intestines to liver

What is the circulatory route arteriovenous anastomosis?

Shunt

-Artery flows directly into vein bypassing capillaries

What is venous anastomosis?

most common

-One vein empties directly into another capillary

-Reason a vein blockage is less serious than arerial blockage

What is arteriocenous anastomosis?

Two arteries merge

-Provides alternative routes of blood supply

-coronary circulation

-common around joints

What is blood flow?

The amount of blood flowing through an organ, tissue, or blood vessel in a given time

What is perfusion?

The flow per given volume or mass of tissues in a given time

WHat is peripheral resistance?

Opposition to flow hat blood encounters in cessels away from the heart

What are the factors of blood resistance?

-Blood Viscosity

-Vessel Length

-Vessel radius

What does a decrease in blood viscosity do?

Increase flow rate

What does a increase in blood viscosity do?

Decrease flow rate

What does a decrease in vessel length do?

Increase pressure and flow rate

What does a increase in vessel length do?

Decrease pressure and flow rate

What does a decrease in vessel radius do?

Increase flow and decease pressure

What does a increase in vessel radius do?

Decrease flow and increase pressure

What is vasoconstriction?

When smooth muscle f the tunica media contracts and reduces vessel radius