Circulatory System Chapter 4
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Transcript of Circulatory System Chapter 4
Circulatory System Chapter 4
Veterinary Technology
Introduction Vertebrates have a closed circulatory system,
which generally confines blood within its walls. The closed systems coevolved with the respiratory
and lymphatic systems. In fish, blood flows in one circuit. In birds and mammals, it flows in two through a
partitioned heart that works as two side-by-side pumps.
The double circuit supports the high levels of activity typical of most vertebrates that evolved on land.
Blood Components and Functions When blood is spun in a centrifuge, the
liquid and solids portions separate and the solids settle to the bottom.
This cellular portion makes up about 30% to 45% of total blood contents.
The remaining fluid is plasma.
what’s in
red blood cells
white blood cells
platelets
plasma
carbon dioxide
digested food
waste (urea)
hormones
oxygen
The Blood
plasma
red blood cell
white blood cell
platelets
Red Blood Cells – AKA Erythrocytes
contain hemoglobin, a molecule specially designed to hold oxygen and carry it to cells that need it.
can change shape to an amazing extent, without breaking, as it squeezes single file through the capillaries.
a biconcave disc that is round and flat without a nucleus
An adult dog has about 6 to 8 million RBC’s per microliter!
Red Blood Cells – AKA Erythrocytes Erythropoieses = the production on RBC’s
by the bone marrow. Erythropoietin = hormone produced in the
kidney to stimulate RBC production. When and why do animals need this?
White Blood Cells – AKA Leukocytes
there are many different types and all contain a big nucleus.
the two main ones are the lymphocytes and the macrophages.
some lymphocytes fight disease by making antibodies to destroy invaders by dissolving them. other lymphocytes make antitoxins to break down poisons.
macrophages ‘eat’ and digest micro-organisms .
Blood Components and Functions Types of White Blood cells – page 48 Types of Blood proteins – page 46
PlateletsPlatelets are also produced in the bone marrow, help with blood clotting.
Platelets produce tiny fibrinogen fibers to form a net. This net traps other blood cells to form a blood clot.
Platelets work with the protein Fibrinogen
What is the process of blood clotting?
Plasma – about 94% water
A straw-colored liquid that carries the cells and the platelets which help blood clot.
• carbon dioxide• oxygen • nutrients • glucose• electrolytes• proteins – about 8%• minerals• vitamins• hormones• waste materials like urea.
It also contains useful things like;
Directional Terminology Helpful to know, when describing
anatomy and describing blood flow.
Medial refers to being directed toward the middle or median plane of the body. The median plane is best
described as a line that would divide the body in half from head to tail.
2. Lateral refers to being directed away from the median plane of the body
1. Cranial is directed toward the head or cranium. It is used on the legs to describe
structures above the metacarpal/ankle/fetlock joint.
Dorsal is used to describe structures below the aforementioned joint, along with palmar or plantar.
2. Caudal is directed toward the rear of the body. It is used for structures on limbs above
the metacarpal/ankle/fetlock joint.
1. Dorsal refers to a body part that is directed toward the back of the body. For instance, the hip joint is
dorsal to the knee joint.2. Ventral refers to a body part
that is directed toward the belly. For example, the elbow joint is
ventral to the shoulder joint
1. Proximal is directed toward the body from foot to head.
2. Distal is directed away from the body from head to foot
Blood Vessels and Blood Flow In Mammals, The heart is a four-
chambered, hollow muscle used to pump blood. It provides two separate paths.
1. Pulmonary Circuit: moves blood to lungs. Right Ventricle is the pump
2. Systemic Circuit: moves blood to the rest of the body. Left Ventricle is the pump
Blood Vessels and Flow Page # 52 may be more helpful than my
description. Be sure and read this section! (pages 50
– 54)
Lungs
Body cells
Mammal’s circulatory system is a double circulatory system. This means it has two parts .
the right side (Pulmonary) of
the system
deals with deoxygenated
blood.
the left side (Systemic) of the system deals with
oxygenated blood.
How does the Heart work?
blood from the body
blood from the lungs
The heart beat begins when theheart muscles relax and bloodflows into the atrium. The
relaxation phase is called the diastole phase
STEP ONE: The Cardiac cycle
The atrium then contract andthe valves open to allow bloodinto the ventricles. The contraction phase is called systole.
How does the Heart work?
STEP TWO: The Cardiac Cycle
How does the Heart work?
The valves close to stop bloodflowing backwards.
The ventricles contract forcing the blood to leave the heart.
At the same time, the atria arerelaxing and once again filling
withblood.
The cycle then repeats itself.
STEP THREE: The Cardiac Cycle
Mammalian Heart Structures The heart is located low in the chest between the
two lungs, and is contained within a fine membrane,
called the pericardium. The wall is mainly composed of cardiac muscle, the myocardium. Smooth epithelium tissues lines both the inside and outside of the myocardium.
There are 3 types of blood vessels
a. ARTERY
b. VEIN
c. CAPILLARY
The ARTERY
thick muscle and elastic fibres
Arteries carry blood away from the heart.
Break down into smaller arterioles as they reach the lungs
the thick muscle can contract to push the blood
along.
the elastic fibres allow the artery to stretch
under pressure
The VEINVeins carry blood towards from the heart.
thin muscle and elastic fibres
veins have valves which act to stop the blood from going in the wrong direction.
body muscles surround the veins so that when they contract to move the body, they also squeeze the veins and push the blood along the vessel.
The CAPILLARYCapillaries link Arteries with Veins
the wall of a capillaryis only one cell thick
they exchange materials between the blood and other body cells (tissues)
The exchange of materials between the blood and the body can only occur through capillaries.
artery vein
capillariesbody cell
The CAPILLARYA collection of capillaries is known as a capillary bed.
SUMMARYcopy and complete the following;Arteries take blood ______ from the heart. The walls of an artery
are made up of thick _________ walls and elastic fibres. Veins
carry blood ________ the heart and also have valves. The
_________ link arteries and veins, and have a one cell thick wall.
Blood is made up of four main things ______, the liquid part of
the blood; Red Blood Cells to carry ______; White Blood cells to
protect the body from disease and _________ to help blood clot.
away
platelets
towards
capillaries
plasma
oxygen
muscular
Electrocardiograms, Heart Sounds and Blood Pressure The rate at which the heart beats is
controlled by the nervous system. Pacemaker cells (system): the cells that
begin the heartbeat, and help control the rhythm. AKA: Sinoatrial (SA) node Found in the right atrium
Blood Pressure The highest numbers is both the systole
and diastole phases. Measured in millimeters of mercury Typical human is 120/80 mm Hg. Systolic over diastolic pressure Doppler machine http://www.youtube.com/watch?v=no7Z8H8yCyQ
Blood Pressure Ways to regulate BP:
BP is higher is arteries than veins Page 59 Kidneys produce a enzyme called renin
when a low BP is detected. BP is lower in the limbs (fight gravity)
Why do you faint when you lock your knees?
Electrocardiograms, Heart Sounds and Blood Pressure Electrocardiograph – the instrument that
picks up the electrical signal running through the body
Electrocardiogram – (ECG) the tracing made by the instrument. Identifies problems associated with the
contraction of the heart.
Electrocardiograms, Heart Sounds and Blood Pressure sinus rhythm = Normal, consistent rate Sinus trachycardia = faster than normal,
but with a normal rhythm Sinus bradycardia = slower that normal,
but with a normal rhythm Artial fibrillation = pacemaker not
working, irregular Asystole = flat line!
Cardiopulmonary resuscitation (CPR)
Electrocardiograms, Heart Sounds and Blood Pressure
Heart murmurs: defective valve or abnormal flow of blood. Makes a swishing noise In you notes: read page 56: Describe the
typical heart noise and the action that happens for that noise to occur.
Clinical Practice Blood analysis is the process of testing blood to
determine its characteristics. Samples are collected and tested to determine
various attributes.
Science Starter Read page 45 What will happen to Sconic’s foot when
the blood supply was stopped? For a short period of time For a long (several days) period of time?
Clinical Practice Blood typing is a kind of analysis that is used in
genetic studies. Genetic markers in the blood can
be used to determine the parents of offspring.
For example, the identity of the sire of a calf can be determined by blood typing a calf.
Newer DNA analysis procedures may be replacing some uses of blood typing.
Capillary Refill Time (CRT) Check on gums, tissues under nails. 1. Apply pressure for 5 seconds 2. remove the pressure In a healthy animal , the color should
return to pink in just one second!
Clinical Practice: vocab! Hypo- (value is below normal) Hyper- (value is above normal) -enima (used to describe levels in the blood
stream -penia (WBC count less than normal) -cytosis (WBC count higher than normal) -ia (other cells are elevated) Erythro- (referring to RBC) Auto- (referring to self)
Anemia Low RBC count Supplies less oxygen to the tissues Signs: fatigue during exercise, weak, sluggish,
inactive. Not an actual disease – sign of other diseases Causes:
1. excessive blood loss 2. shortened life of RBC 3. decreased production of RBC
Parasites??? (hookworm) Acetaminophen (Tylenol) Autoimmune Disease