Anatomy and Physiology4

End of Term project

THE CARDIOVASCULAR SYSTEM
The cardiovascular system includes the heart, blood vessels and blood. The heart
pumps blood and the blood vessels deliver it through the body. When oxygen is
inhaled it goes into the alveoli which are tiny air containing sacs. It is exchanged
for dioxide and goes through a process of diffusion. The rich oxygen blood goes to
the heart via the pulmonary vein. From the heart, it is pumped through the aorta
throughout the body where it is needed for the production of energy. Arteries
thick-walled tubes, carry blood filled with nutrients away from the heart to all parts
of the body. Arteries divide into smaller arterioles and then into smaller capillaries,
the smallest of all blood vessels. One arteriole can serve a hundred capillaries. It is
through capillaries that blood is able to carry out its work when it gives up what
cells need and take away the waste products, include what they don’t need. The
cells receive the oxygen from the smallest blood vessels and at the same time
waste products are exchanged. The waste material, including caron dioxide, travels
in the veins to the heart through the vena cava. From the heart, it is pumped to the
lungs via the pulmonary artery and changed to oxygen this cycle repeats
continuously. Oxygenated blood pumps through the arteries are bright red in
colour. Blood that contains high levels of carbon dioxide is a dull red colour.
THE HEART
The heart is divided into four chambers and considered as two pumps in one.
The four chambers are:
 The right atrium
 The right ventricle
 The left atrium
 The left ventricle
The right side of the heart is separated by the left side by a muscular wall called the
interventricular set-up. This prevents oxygenated blood from mixing with
deoxygenated blood. In each half of the heart is the atrioventricular valves which
ensures a unidirectional flow of blood through the heart and the blood vessels. The
valves prevent backflow of blood within the heart. The right av is called the
tricuspid valve because it contains three fibrous flaps or cusps. The left av has two
flaps and is called the bicuspid valve.

ARTERIES AND ARTERIOLES

Arteries carry blood away from the heart. As arteries leave the heart, they branch
off into smaller and smaller arteries and then into arterioles.

VEINS AND VEINULES

The deoxygenated blood flows back to the heart in venules after the exchange of
gases and nutrients take place between cells and capillaries. As veinules decrease
in number, the increase in size and move to veins. Blood that flows back to the
heart are under a lower pressure than leaving the heart.
CAPILLARIES
The arterioles transport blood to the capillaries. These are the smallest blood
vessels that make contact with cells in the body. These are microscopic and they
exchange gasses and nutrients take place between the cells and the capillaries
BLOOD
Blood is made up of cells and platelets that are suspended in a liquid called plasma.
Oxygen, carbon dioxide, blood proteins, waste products, salts, glucose, fatty acids
and enzymes can be found in a dissolve state in plasma. The cells in blood make up
45% volume while the 55%is plasma. Two types of cells found in blood which are
erythrocytes or red blood cells and leukocytes or white blood cells.
WHITE BLOOD CELLS
These cells perform to protect the body from bacteria, viruses and foreign objects
in our body. These cells manufactured in the bone marrow.
RED BLOOD CELLS
These comprise of approximately 99% of all blood cells. They are disc that are
thicker at the edges than in the middle and have a life span of 120 days. Red blood
cells contain a protein called haemoglobin, which has a high affinity to oxygen and
carbon dioxide. These are reversibly combine meaning they can rapidly diffuse to
and from cells, bringing in much needed oxygen and nutrients.
PLATELETS
These are colourless cell fragments that help in blood clotting functions.
FUNTIONS OF THE BLOOD
TRANSPORTATION
The blood acts as a transport which nourishes the body and moves from one place
to another. Oxygen is carried from the lungs to the heart and all of the body parts.
During this, carbon dioxide is transported to the cells of lungs to be expelled.
Blood plasma carries the nutrients from the digestive tract to where they are
needed. The blood is used for transport. Arteries, veins and capillaries are routes
used by the blood to carry these substances to their destination.
REGULATION
Body temperature is regulated through the blood in many ways. If the body is hot,
blood vessels in the dermis layer will dilate. If it is cold, the body conserves heat.
Cells and tissues in the body require a pH level of 7.4 to function optimally. The
fluid among tissues receives compounds and ions from the blood plasma to
maintain these levels.
PROTECTION
White blood cells protect the blood. They guard against bacteria, viruses and other
harmful object. They destroy and remove them from the body. They also protect
the body from blood loss by forming blood clots where it’s the skin is broken.
HEART DISEASES
WHAT IS A VASCULAR DISEASE?
This is mainly caused by the thickening of arteries from fatty deposits or plaque.
When arteries become narrow it becomes difficult for saving blood to flow through
them and reach the tissue and organs to function properly. When this occurs, an
inadequate blood supply to the tissues damage and even death. Vascular diseases
mostly affect the brain, heart and legs.
WHAT IS A HEART ATTACK?
This happens when blood supply is reduced and results into less oxygen flow in the
muscle. This puts pressure on the heart and responds adversely. When the oxygen
supply is low a small blood clot can form in the blood vessel blocking blood flow
beyond the clot. Part of the heart loses blood and the muscle dies. Heart attacks
occur when a harsh pain occurs on the left hand followed by mammoth chest pain.
HIGH BLOOD PRESSURE
This is a force against walls of your arteries as your heart pumps blood. Normal if
it is below Blood pressure is measured in milimetres and usually given in two
numbers. One or both of these numbers can be too high. The systolic pressure is
considered normal if it is below 80 and if it is high, it over 90. Persistent high
blood pressure is a risk factor for strokes and heart failure. Symptoms, include
headaches, ringing or buzzing in ear dizzy or confused.
ISCHEMIC HEART DISEASE
This is the opposite of hypertension which reduces the flow of blood to the heart.
This is a condition of recurring chest pain or discomfort occurring when part of the
heart doesn’t receive enough blood. The reduced blood flow occurs when the heart
requires greater blood flow. This can be caused by the buildup of plaque in the
walls of the heart.
HEART RYTHM DISORDERS
Heart rhythm disorders, are irregularities in the in the sound that the heart makes
when listened to by a doctor via the means of a stethoscope. Irregular heartbeats
may be caused by many different factors, including coronary artery disease,
electrolyte imbalances in the blood and changes in your heart muscle due to injury
from heart attacks. Heart murmurs are harmless at other times; however, it can be
serious and need to be checked out more thoroughly by a doctor for better analysis.
WHAT ARE RISK FACTORS?
These include:
 Unhealthy diets
 Being overweight
 Diabetes
 High cholesterol levels
 Lack of exercise
 Family history
  High blood pressure
 Stress
TAKING THE PULSE
The pulse represents the ejection of blood from left ventricle to the general
circulation of the body. Ventricles have two phases: diastole the time when
ventricles rest so they can fill with blood and systole, the time when ventricles
contract to send blood either the lungs or the rest of the body. The pulse represents
the variations in blood pressure from diastole to systole. To measure the systolic
and diastolic blood pressure readings. there are nine points where the pulse can be
taken. The most common point is the radial pulse located in the wrist.

THE NERVOUSE SYSTEM

CENTRAL NERVOUS SYSTEM
The nervous system works through electrical impulses throughout our body. It is
an organized electronic mechanism that produces movements based on information
received. It is a specialized system that controls the actions and reactions in the
body. The nervous system can be divided into two subdivisions: the central and
peripheral nervous system. The central nervous system includes the brain and
spinal cord. The brain is a primary component of the nervous system and is located
in the cranial cavity. It is protected by the skull and can be damaged by bumps and
grinds. The brain receives sensory input from the spinal cord as well as from the
nerves. It devotes most of its volume to process its various sensory inputs.
THE SPINAL CORD
The spinal cord runs along the dorsal side of the body and links the brain to the rest
of the body. The spinal cord is encased in bony vertebrate that column. This
provides protection for the spinal cord. It connects a large part of the peripheral
nervous system to the brain. The grey matter of the spinal cord consists mostly of
cell bodies and dendrites. The surrounding white matter is made up of bundles of
intraneuronal axon. Some tracts are ascending, and others are descending. Both the
spinal cord and the brain consist of white matter and grey matter. A basic nerve
cell consists of a cell body, an axon and many dendrites. Dendrites increase the
surface area of the cell which makes it possible for it to receive many connections
with adjoining nerve cells. signals pick up by the dendrites travel through the cell
and continue through the axon. synaptic bulbs on the ends of the axon make
connections with other nerve cells, with tiny gap between the cells. When the
electrical impulse reaches the end of the axon it is transferred to the next nerve
cell. It is this small space between the two cells which is referred as a synapse. The
neurotransmitter is a chemical released when the transmissions of the signal across
a synapse. It acts as on receptor sites on the second cell’s membrane, changing its
permeability to sodium ions and thus simulating depolarization. The characteristic
of nerve cells sets them apart from other cells of the body which allow them to
transmit signals is their ability to depolarize.
PERIPHERAL NERVOUS SYSTEM
The peripheral nervous system is made up of nerves called cranial nerves that
extends to the brain and spinal nerves extend out of the spinal cord to all the distal
parts of the body.
FUNCTIONS
The central and the peripheral nervous system function these main functions:
1. Collecting information
2. Processing and evaluating information
3. Response to the information evaluated
All of these actions are done in a fraction of a second. Visual receptors will relay
this information to the brain which will information to the brain which will process
this information and provide an appropriate response in terms of shot selections.
FUNCTIONAL DIVISION OF THE NERVOUS SYSTEM
 Sensory division- Receive sensory information
 Motor division- Transmit motor impulses from the central nervous system
 Somatic sensory- Transmit nerve impulses
 Visceral sensory- Transmits nerve impulses from blood vessels and viscera
 Somatic motor system- Conducting nerve impulse from the central nervous
system
 Autonomic nervous system- Cannot dictate to these systems how to function
 Sympathetic nervous system- increases heartbeat and constricts your blood
vessels.
 Parasympathetic system- this system is responsible for rest and recovery
  Reflex- the rapid automatic involuntary reaction of muscles or glands to a
stimulus

THE RESPIRATORY SYSTEM

Respiration is the act of breathing. This system is responsible for supplying oxygen
to the blood and removing waste mainly carbon dioxide. During this process
carbon dioxide must be removed