Chapter 15 - Cardiovascular System (1) (8).txt

Volume of blood pumped per day

The heart pumps 7,000 liters of blood through the body each day

Number of heart contractions in a lifetime

The heart contracts 2.5 billion times in an average lifetime

Order of blood flow through vessels

Arteries → arterioles → capillaries → venules → veins → back to heart

Components of the cardiovascular system

The heart and all blood vessels

Definition of Cardiovascular

Refers to both the heart and blood vessels

Function of heart's pumping action

Transports blood through blood vessels

Two circuits formed by blood vessels

Pulmonary Circuit and Systemic Circuit

Function of Pulmonary Circuit

Transports oxygen-poor blood to lungs and back to heart

Function of Systemic Circuit

Transports oxygen-rich blood to body cells and back to heart

Blood types in heart sides

Left side contains oxygen-rich blood; right side contains oxygen-poor blood

Shape and function of the heart

Hollow, cone-shaped, muscular pump

Location of the heart

In the mediastinum of the thoracic cavity, superior to the diaphragm

Number of heart chambers

4 chambers - 2 atria and 2 ventricles

Average size of the heart

14 cm long and 9 cm wide

Location of the heart in thoracic cavity

Posterior to sternum, medial to lungs, anterior to vertebral column

Significance of heart's location

Protected by rib cage, proximity to lungs for efficient oxygenation

Definition of mediastinum

Central compartment of thoracic cavity housing vital structures

Pericardium definition

Covering over heart and large blood vessels

Layers of Pericardium

Fibrous, Parietal, Visceral (Epicardium)

Heart wall layers

Epicardium (Visceral Pericardium), Myocardium, Endocardium

Left Ventricle

Pumps oxygenated blood into the aorta for distribution throughout the body

Aortic Valve

Prevents backflow of blood from the aorta into the left ventricle

Superior Vena Cava

Returns deoxygenated blood from the upper body to the right atrium

Inferior Vena Cava

Returns deoxygenated blood from the lower body to the right atrium

Pulmonary Arteries

Carry deoxygenated blood from the right ventricle to the lungs

Pulmonary Veins

Carry oxygenated blood from the lungs to the left atrium

Aorta

Distributes oxygenated blood from the left ventricle to the body

Coronary Arteries

Supply blood to heart tissues

Cardiac Cycle

Sequence of events in the heart from one heartbeat to the next

Systemic Circulation

Carries oxygenated blood away from the heart to the body

Pulmonary Circulation

Carries deoxygenated blood from the heart to the lungs

Blood Pressure Regulation

Adjusts the force and volume of blood flow

Venous System

Returns deoxygenated blood back to the heart

Arterial System

Carries oxygenated blood away from the heart

Cardiovascular System

Responsible for transporting nutrients, oxygen, and hormones

Heart Transplant

Replacement of a failing heart with a donor heart

Left Ventricular Assist Device (LVAD)

Mechanical half-heart used temporarily

Stem Cell Technology

Culturing cardiac muscle tissue from stem cells

Cardiac Conduction System

Specialized tissue coordinating heart impulses

Electrocardiogram (ECG)

Records electrical changes in the heart

Capillaries

Smallest blood vessels for exchange of substances

Blood Pressure Regulation

Crucial for maintaining adequate blood flow

Venous System

Returns deoxygenated blood to the heart

Arteries

Blood vessels carrying oxygenated blood away from the heart to body tissues

Cardiovascular system changes during aging

Include decreased vessel elasticity, reduced cardiac output, and increased risk of diseases

Common cardiovascular diseases

Hypertension, coronary artery disease, heart failure, arrhythmias

Cardiovascular system

Consists of heart, blood vessels, blood, circulates nutrients, oxygen, waste

Heart function

Acts as a pump moving blood, supplying oxygen, nutrients, removing waste

Blood components

Red blood cells, white blood cells, platelets, plasma

Veins

Vessels carrying deoxygenated blood back to the heart from body tissues

Aorta

Largest artery originating from the heart's left ventricle, distributing oxygenated blood

Capillaries

Smallest vessels facilitating oxygen, nutrient, waste exchange between blood and tissues

Blood pressure

Force of blood on vessel walls, measured in mmHg

Cardiac cycle

Events in one heartbeat, atria and ventricles contraction and relaxation

ECG

Test measuring heart's electrical activity for normal function

Systemic circulation

Carries oxygenated blood from heart to body, returns deoxygenated blood

Pulmonary circulation

Moves deoxygenated blood from heart to lungs, returns oxygenated blood

Red blood cells function

Transport oxygen to tissues, return carbon dioxide to lungs

White blood cells function

Part of immune system, fight infections and diseases

Platelets

Aid in blood clotting and wound healing

Plasma

Liquid part of blood transporting cells, nutrients, hormones, waste

Hypertension

High blood pressure causing health issues like heart disease

Atherosclerosis

Buildup of plaque in arteries reducing blood flow

Venous system function

Returns deoxygenated blood from tissues to heart

Coronary arteries role

Supply oxygen-rich blood to heart muscle

SA node

Controls heart rate

Sympathetic and parasympathetic fibers

Modify heart rate based on conditions

Baroreceptor reflexes

Maintain blood pressure levels

Cardiac control center function

Regulates autonomic impulses to heart

Arrhythmia

Altered heart rhythms like fibrillation, tachycardia, bradycardia

Angiogenesis

Formation of new blood vessels controlled by VEGF

Arteries structure

Thick walls with three layers:intima, media, adventitia

Arterioles role

Receive blood from arteries, carry to capillaries

Capillaries function

Sites of substance exchange between blood and cells

Venules function

Receive blood from capillaries, conduct to veins

Arteriole

Small vessel branching from artery leading to capillaries

Venule

Small vessel returning blood from capillaries to veins

Antiangiogenesis drugs

Treat cancer and macular degeneration

Capillaries regulation

Controlled by precapillary sphincters

Capillary openings

Found where endothelial cells overlap

Capillary permeability

Varies with slit sizes in walls

Capillary network density

Determined by tissue metabolic rate

Muscle and nerve tissues

Rich capillary supply due to high oxygen and nutrient demand

Cartilage

Fewer capillaries due to lower metabolic rate

Capillaries

Exchange gases, nutrients, and byproducts in cardiovascular system

Diffusion

Primary method of transfer in capillary exchange

Lipid-soluble substances

Transfer through capillary membranes via diffusion through the cell membrane

Water-soluble substances

Transfer through capillary membranes via diffusion through membrane channels and slits

Hydrostatic pressure

Forces molecules through the membrane during filtration

Filtration pressure

Derived from ventricular contraction in capillary exchange

Osmotic pressure

Created by impermeant solutes like plasma proteins in capillaries

Osmotic pressure

Draws water into capillaries, opposing filtration

Arteriolar end of capillary

Substances leave due to higher hydrostatic pressure

Venular end of capillary

Water enters due to higher osmotic pressure

Venules

Microscopic vessels transporting blood from capillaries to veins

Veins vs

Veins have thinner walls and serve as blood reservoirs

Tunica media in veins

Less developed compared to arteries

Veins

Carry blood under low pressure and function as blood reservoirs

Veins

Often have flap-like valves to prevent backflow

Arteries

Carry blood under high pressure from heart to arterioles