The Circulatory System Quiz: 5/16

Function: Transports nutrients & wastes Contains cells that fight infections Helps maintain body temperature by transporting heat

The Circulatory System All organisms must be able to transport nutrients and wastes. Smaller organisms rely on _________ for this movement; humans require an organized circulatory system for the movement of substances through the body. We have a _______ circulatory system, which means our blood is __________________. The human circulatory system includes the heart, the blood vessels, and the blood. diffusion closed contained in vessels

I. THE HEART (pp. 943-946) ADD TO NOTES The heart itself is mostly composed of ________ muscle which forms a thick layer of tissue known as the ____________. Humans have a __ chambered heart, divided by a __________ into right and left sides to prevent cardiac myocardium 4 septum Mixing of blood

A. Structure ADD TO NOTES 1. Chambers a. Atria (atrium = singular) _______ chambers of the heart that ________ blood. b. Ventricles - _______ chambers of the heart that ________ blood. 2. Valves – Flaps of tissue that keep blood flowing _________________ Upper receive lower pump in one direction

B. Pathway of Blood Through the Heart ____________________________________________________________________________________ ADD TO NOTES vena cava right atrium right ventricle pulmonary artery lung pulmonary vein left atrium left ventricle aorta body

C. Circulatory Pathways 1. Pulmonary Circulation – The blood entering the right atrium from the body is ____ in oxygen and _____ in carbon dioxide. The flow of blood from the right side of the heart to the _____ and back to the heart is referred to as ___________ circulation. low high lungs pulmonary

C. Circulatory Pathways 2. Systemic Circulation – The blood entering the left atrium from the lungs is _____ in O2 and _____ in CO2. The flow of blood from the left side of the heart to the ______ and back to the heart is referred to as __________ circulation. high low body systemic

D. The Heartbeat 1. Stimulus for Contraction Although the brain can change the rate & force of contraction, the heart generates and maintains its own beat. There is a small cluster of cardiac muscle cells in the ______________ referred to as the __________. They trigger an ___________ impulse that stimulates the contraction of cardiac muscle cells. right atrium pacemaker electrical

The Sinoatrial Node Contraction of Atria Contraction of Ventricles Sinoatrial (SA) node Conducting fibers Atrioventricular (AV) node

D. The Heartbeat 2. The Pulse The powerful contraction of the _________ causes a surge of blood to leave through the _____. This surging action of the blood continues into the ______ that branch off from the aorta. Each contraction of the left ventricle results in another surge of blood in the arteries leading away from the heart. This surge can be felt and is known as the _____. left ventricle aorta arteries pulse

Blood Vessels & Blood

Blood Vessels Arteries carry blood _____from heart carry oxygen ____blood (except for__________) Have thick elastic walls surrounded by _____muscle ____is the largest artery in the body away rich pulmonary smooth Aorta

Blood Vessels Capillaries ________ blood vessels Walls are only 1 cell thick This is where the exchange of ______ & _____ takes place smallest nutrients waste

Blood Vessels Veins Collect blood and carry it _____ to the heart back Carry oxygen _______ blood (except for _____________ veins) Have thinner and less elastic walls Have _______to keep blood flowing to heart and not _________ Contraction of _________ muscles help to move blood toward the heart The ____________is the largest vein in the body back poor pulmonary valves backwards skeletal vena cava

Artery vs. Vein

Blood Pressure: the force of blood on the walls of the arteries Falls when the heart ______ Heart is always under pressure in order to keep blood flowing through it Regulated by autonomic nervous system ________ also regulate blood pressure by controlling amount of water in blood- when blood pressure is high, more water is__________; this reduces blood volume relaxes Kidneys removed

Blood Pressure Blood against the blood vessel’s walls The systolic pressure refers to the pressure recorded while the ventricles pump the blood. The diastolic pressure refers to the pressure recorded as the ventricles fill with blood. A normal blood pressure is 120/80

Blood Pressure High blood pressure forces heart to ___________ people more likely to develop heart disease obesity is one cause controlled by weight control, exercise, and diet work harder

Blood Makes up 8% of body –____ to___ liters Components of blood 6 4 45% = ____ blood cells, ______ blood cells and platelets 55% = plasma mostly ________- 90% contains salts, sugars, and plasma proteins 6 4 red white water

What does blood contain? 50% Water 45% Erythrocytes 4% Plasma with Substances 1% Leukocytes + Platelets

Blood Plasma proteins Red blood cells- erythrocyte- RBC infection Several types of proteins that fight__________, regulate osmotic pressure & help blood ____________ Red blood cells- erythrocyte- RBC contain ________________- iron containing protein that increases ___________ carrying ability of RBC’s produced in ______bone marrow mature RBC’s have no nucleus so can’t divide live about 120 days – when they die they are destroyed & recycled by spleen infection clotting hemoglobin oxygen red

Blood White blood cells – leukocytes- WBC Platelets infections fewer in numbers than RBC produced in bone marrow live for many months or years more than 20 different types guard against________________, fight_______________, and attack ________________ an increase in the number of WBC’s is an indication the body is fighting an _____________________ Platelets fragments of cells when blood vessel is injured, platelets become sticky; they cluster around the wound and release a series of chemicals that start a clotting reaction a protein called __________forms a net that traps RBCs and forms a ______ infections pathogens bacteria infection fibrin clot

Blood Clotting Break in Capillary Wall Blood vessels injured. Clumping of Platelets Platelets clump at the site and release thromboplastin. Thromboplastin converts prothrombin into thrombin.. Clot Forms Thrombin converts fibrinogen into fibrin, which causes a clot. The clot prevents further loss of blood..

DISORDERS ATHEROSCLEROSIS Fatty deposits called plaque Builds up in walls of arteries Obstructs flow Also a risk if clot breaks free and blocks flow elsewhere

Disorders (cont) Heart Attack Atherosclerosis in coronary artery Heart muscle begins to die Symptoms Nausea Shortness of breath Severe chest pain IMMEDIATE MEDICAL ATTENTION NECESSARY

Disorders Continued Anemia Caused by either a deficiency of red blood cells or hemoglobin in RBCs. Less oxygen available for cells results in a lack of energy due to decreased ATP production.

Disorders (cont) Hypertension High blood pressure Hearts works harder than necessary Increases risk of heart attack or stroke

Disorders (cont) Stroke Blood clot gets stuck in blood vessels leading to brain Brain cells die due to lack of oxygen Or blood vessel burst Can lead to paralysis, loss of ability to speak death

The Respiratory System

The function of the respiratory system is to bring about the exchange of _O2__ and _CO2___.

_Pharynx_____ - Upper throat A. Airway to the Lungs _Nasal Cavity______ - Begin the process of warming, filtering, moisturizing the air _Pharynx_____ - Upper throat _Larynx____ - Also known as the voicebox. Bands of tissue that tighten and vibrate to create sound when air passes through. Attached to the larynx is a flap of tissue called the _epiglottis_____. The epiglottis closes when food is swallowed to prevent food from entering the _respiratory___ tract.

_Trachea___ - Airway supported by bands of _cartilage_______ to prevent it from _collapsing_____ when air passes in and out _Bronchi_________ - Trachea divides into two tubes leading to each _lung_____ Trachea and bronchi are lined with _cilia____ and cells that secrete _mucus_____. The mucus traps _pathogens____ and other contaminants. The cilia beat _upwards__ to sweep contaminants toward the _pharynx_____.

B. Inside the Lungs _Bronchioles_____ - Smaller branches leading from bronchi. Contain _smooth____ muscle tissue to facilitate air flow. _Alveoli__________ - The bronchioles end in millions of tiny sacs called alveoli. Site for the exchange of _O2___ and _CO2____. Each alveolus is surrounded by a _capillary_______ to allow _ O2____ to _diffuse____ from the lung to the blood to be delivered to cells for _cellular respiration___ and _ CO2____ to diffuse from the blood to the lung to be exhaled.

C. Pathway of Air Nasal cavity  pharynx  larynx  trachea bronchi  bronchiole  alveoli

Breathing A. Inhalation & Exhalation - Breathing is a _passive___ response to a change in _pressure_______ in the chest cavity. Although there are no _muscles____ attached to the lungs, the change in pressure is caused by the contraction of muscles involved in breathing. Diaphragm – Dome-shaped muscle located below (but not attached to!) the _lung_____. When the diaphragm _contracts_______, it flattens which _increases_____ the volume of the chest cavity and _decreases____ the pressure. Air rushes into the lungs.

Intercostal Muscles – Also contract to further _increase_____ volume of chest cavity As the diaphragm and intercostal muscles relax, volume of the chest cavity _decreases___, and the _elasticity_______ of the lungs help force the air back out. B. Control of Breathing Breathing is controlled by the _medulla oblongata__, which is monitoring the concentration of _CO2____ in the blood.

Diseases of the Respiratory System Emphysema – Progressive disease in which _alveoli_______ lose their elasticity. Affected individuals cannot fully exhale which reduces ability to inhale. O2 and CO2 do not diffuse properly. All _smokers________ eventually develop emphysema. Asthma – Allergic reaction that affects _smooth______ muscles of _bronchioles_______. They _constrict______ which prevents airflow into the _alveoli_____. Gas exchange is reduced.

Smoking – Three dangerous substances found in cigarette smoke are nicotine, carbon monoxide, and tar. Nicotine – stimulant that increases heart rate, constricts blood vessels; _increases______ blood pressure. Carbon monoxide – binds to _hemoglobin____; reduces oxygen-carrying capacity of _hemoglobin_____ blood cells. Also, combination of nicotine & CO paralyzes _cilia____ lining respiratory tract resulting in frequent respiratory _infections__________. Tar – carcinogen; smokers have a much higher incidence of lung cancer.