Study Guide - LTT

Study Guide

HLTAAP001 recognise healthy body systems

HLTAAP001 Recognise healthy body systems

Study Guide v4.1 1

Contents

INTRODUCTION ............................................................................................................................................ 2

ANATOMICAL POSITIONS & DIRECTIONS ................................................................................................ 3

CELLS, TISSUES AND ORGANS ................................................................................................................. 5

THE FUNCTION OF CELLS ............................................................................................................................... 5

THE STRUCTURE AND FUNCTION OF TISSUES .................................................................................................. 6

ORGAN SYSTEMS .......................................................................................................................................... 7

THE CARDIOVASCULAR SYSTEM ............................................................................................................. 8

THE HEART ................................................................................................................................................... 8

BLOOD ......................................................................................................................................................... 10

THE RESPIRATORY SYSTEM .................................................................................................................... 11

THE MUSCULAR SYSTEM ......................................................................................................................... 12

THE SKELETAL SYSTEM ........................................................................................................................... 13

THE ENDOCRINE SYSTEM ........................................................................................................................ 14

THE DIGESTIVE SYSTEM........................................................................................................................... 15

THE REPRODUCTIVE SYSTEM ................................................................................................................. 16

THE URINARY SYSTEM ............................................................................................................................. 17

THE INTEGUMENTARY SYSTEM .............................................................................................................. 18

THE LYMPHATIC SYSTEM ......................................................................................................................... 19

THE IMMUNE SYSTEM ............................................................................................................................... 20

THE NERVOUS SYSTEM ............................................................................................................................ 21

THE SPECIAL SENSES .............................................................................................................................. 22

SMELL, TASTE, VISION, EQUILIBRIUM AND HEARING ........................................................................................ 22

RELATIONSHIPS BETWEEN DIFFERENT BODY SYSTEMS .................................................................. 23

HOMEOSTASIS ........................................................................................................................................... 27

ELIMINATION OF WASTES FROM THE BODY .................................................................................................... 27

MAINTENANCE OF BODY TEMPERATURE ........................................................................................................ 28

HOW DOES THE BODY MAINTAIN BLOOD PRESSURE? ..................................................................................... 29

FLUID AND ELECTROLYTE BALANCE .............................................................................................................. 30

MAINTAINING A HEALTHY BODY ............................................................................................................. 32

RECOGNISE AND PROMOTE WAYS TO SUPPORT HEALTHY FUNCTIONING OF THE BODY ..................................... 32


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Introduction

The human body is a fascinating network of structures and systems all working interdependently, rivalling the most efficient machines. Consisting of more than 100,000 billion cells each with its own unique role, the body is capable of an extraordinary range of activities all designed to ensure its own survival and to aid in the survival of the human species.

The study of the human body (anatomy) and its functions (physiology) is a most necessary foundation for learning a career that involves an understanding of any small part or function of the body. As a phlebotomist, you are frequently required to perform what is essentially an invasive medical procedure on your clients and this fundamental understanding and recognition of a healthy body system, allows you to be aware of, and analyse anything out of the ordinary.

This guide gives you underpinning information regarding:

• How to work with information about the human body

• The correct use and interpretation of health terminology that describes the normal structure, function and location of the major body systems

• The correct use and interpretation of information that relates to the interrelationships between major components of each body system and other structures

• How to recognise and promote ways to support healthy functioning of the body

• Factors that contribute to maintenance of a healthy body

• How the relationships between different body systems affect and support healthy functioning

• Enhancing quality of work activities by using and sharing information about healthy functioning of the body


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Anatomical Positions & Directions

Anatomical position is the description of any region or part of the body in a specific stance. In the anatomical position, the body is upright, directly facing the observer, feet flat and directed forward. The upper limbs are at the body’s sides with the palms facing forward.

Theses anatomical terms of location are an important fundamental when studying anatomy. They help to avoid any ambiguity that can arise when describing the location of structures. Later, this knowledge can be applied directly to pathology collection, as doctors often use these terms to describe anatomical positions on pathology request forms.

The following is a brief list of anatomical planes and positions:

• Anterior: toward the front of the body

• Abduction: away from

• Adduction: towards

• Afferent: conducting towards a structure

• Deep: closer to the centre of the body

• Distal: farther from the point off attachment or point of reference

• Eversion: turning outward


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• External: pertaining to the outside or outer

• Extension: straightening

• Flexion: bending

• Inferior: (caudal literally ‘tail') - below

• Lateral: toward the side of the body

• Medial: middle, towards the median plane

• Median: in the middle of a structure

• Peripheral: outer edges

• Plantar: pertaining to the sole of the foot

• Posterior: toward the back of the body

• Prone: face or palm down

• Proximal: nearest the centre or given point

• Rotation: (version) - turning

• Superficial: closer to the surface of the body

• Superior: (cephalic) - above or upper

• Supine: face or palm up


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Cells, tissues and organs

The cell is the most basic unit of life and are structural, biological, functioning building blocks of the human body.

Although cells can vary according to what tissue or organ they make up, they have some common qualities in their structure.

These common structural qualities are outlined in the illustration below:

• The Plasma Membrane: A protective outer layer which regulates the passage of materials into and out of the cell

• The Nucleus: The control centre of the cell, which contains the cell’s DNA in the form of chromosomes

• Cytoplasm: Inner contents of the cell, made up of fluid (cytosol) and organelles (Latin for mini organ)

• Organelles: Which include the mitochondria, endoplasmic reticulum, lysosomes, Golgi complex, vacuoles, centrioles, cilia, flagella

The function of cells In a single-celled animal such as bacteria, amoeba or algae, cells are capable of digesting food, growing, respiring (breathing), excreting, reproducing and responding to stimuli.

However, in multi-cellular organisms such humans and animals, the cells need to perform more specialised functions and the varying activity of each cell reflects the operation of the organelles within them.

There are trillions of cells in our body, and at least 200 different types of cells that differ in make-up and function. In a nut-shell though, the function of a human body cell is to provide structure for the body, take in nutrients from food and convert those nutrients into energy. Cells also contain the body’s hereditary material (DNA) and can make copies of themselves.

Common cells group together to form tissues. which is a structural material that makes up the organs within the human body.


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The structure and function of tissues Tissues have different properties and composition that vary according to need; you could rightly compare tissue to the different building materials required to build a house, such as timber, stone, plaster or steel. These materials are all very different in composition but have their own place in a well-constructed building.

The four main types of tissue found within the body are epithelial, connective, muscular and nervous tissue.

• Epithelial: covers surfaces, lines body cavities and forms glands. It consists of cells that are tightly packed together. The outer layer of your skin is a primary example of epithelial tissue.

• Connective: supports and forms the framework of all parts of the body. Cells in connective tissue are embedded within an extracellular matrix. (Think of jelly with chunks of fruit in it). Types of connective tissue are adipose tissue (body fat), bone, cartilage and blood, of which plasma is the extracellular matrix.

• Muscular: composed of cells designed to shorten or contract to produce movement. Can be categorized into skeletal muscle tissue, smooth muscle tissue, and cardiac muscle tissue.

• Nervous: consists of two main types of cells: neurons (able to receive stimuli and send impulses) and neuroglia (form supportive and protective tissue). Makes up brain, spinal cord and the nerves.

An organ is a collection of the above tissues joined to create a structural unit, which serves a common purpose. For example, the heart is made up of cardiac muscle and nervous tissues, held together with connective tissues and lined with epithelium. Each organ has a specialised function and works as part of different body system.


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Organ Systems The human body is made up of different organ systems, which is, two or more organs working together to perform a body function. However, the functions of organ systems often overlap and can be studied in a combined manner. For instance, the circulatory system is made up of the heart, blood vessels and blood. Its purpose is to pump nutrient and oxygen rich blood throughout the body. As such, the circulatory system depends on the respiratory system to supply the oxygen via organs such as the nose, trachea and lungs. Therefore, the two systems can be studied as the one, cardiopulmonary system.

The table below outlines the organs that make-up each system. Note: the muscular and skeletal systems are together as one system for the purposes of this table.

System Organs

Cardiovascular Heart, blood, vessels

Respiratory Nose, pharynx, trachea, bronchus, bronchiole, lungs, alveoli

Musculoskeletal Muscles, joints, bones

Nervous Brain, spinal cord, nerves

Endocrine Glands: pituitary, hypothalamus, pineal, parathyroid, thyroid, adrenals, pancreas, gonads: ovaries ♀; testes ♂, and their hormones.

Digestive Tongue, oesophagus, stomach, liver, pancreas, gall bladder, small intestine, large intestine, rectum, anus

Urinary Kidneys, ureters, bladder, urethra

Reproductive Male: Testes, scrotum, vas deferens, seminal vesicle, prostate, ejaculatory duct, urethra, penis, glans, perineum

Female: Ovaries, fallopian tubes, uterus, cervix, vagina, labia, urethra, clitoris, perineum

Integumentary Skin

Lymphatic/Immune Lymph glands and vessels, lymph, lymphocytes, T and B cells.


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The cardiovascular system

The cardiovascular systems (also known as the circulatory system) primary function is to carry blood all around our body via arteries and veins, depositing oxygen and nutrients - taking away carbon dioxide and waste products. Central to this process is the transport-system pump - the heart.

The Heart The heart is a hollow organ about the size of a fist and is composed of cardiac muscle. It lies under the breast bone in the centre of the cardiothoracic cavity. It is controlled by an electrical current that is initiated in the brain. It is an ever-working engine that beats up to 30 million times a year, 60 to 100 times a minute and pumps approximately 4.7 litres in that time.

In this illustration, the red indicates blood rich in oxygen and the blue indicates oxygen poor blood.


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The cardiovascular system consists of arteries, veins and capillaries. Arteries carry oxygenated blood to the cells of the body, veins carry deoxygenated blood away from the cells.

Arteries

Arteries have thick, muscular elastic walls, they carry blood rich in oxygen and nutrients away from the heart. Arteries branch off forming arterioles with thinner walls that then become capillaries. If a wound lead to an artery or an artery is pierced, blood is bright red and spurts in time with your heartbeat.

Veins

Veins have thin muscular walls and one-way valves that help move blood toward the heart. They carry blood low in oxygen and high in carbon dioxide from the cells back to the heart where it is pumped to the lungs so that the blood can pick up more oxygen. Venules are smaller veins that receive blood from capillaries.

Capillaries

Capillaries are microscopic vessels that surround the cells of the body and facilitate the movement of oxygen and nutrients into the cells and carbon dioxide and waste products away from the cells.


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Blood

Blood is connective tissue, that moves freely throughout the body. It is made up of a liquid (plasma) and cells. It serves the body by transporting gases, nutrients, waste and hormones. It regulates the acidity of fluid in our body to a pH between 7.35 and 7.45, maintains fluid balance and regulates body temperature. Blood is also capable of protecting us from disease and blood loss from injury.

Blood is divided into two main components, plasma (the liquid portion) and the formed elements which includes our cells.

Plasma

About 55% of our total blood volume is plasma, it is a watery straw-coloured fluid in which the cells are suspended.

Cells

Our blood cells are made up of red blood cells (erythrocytes), white blood cells (leukocytes) and platelets (thrombocytes).


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The respiratory system

In order to survive the body needs a constant supply of oxygen, which it obtains from the air around us. The respiratory system facilitates the exchange of air between the lungs and the atmosphere. It also allows for the disposal of carbon dioxide; a waste product of cell metabolism. The ingestion of oxygen and the discarding of carbon dioxide, occurs through the process of respiration or breathing.

The lungs

The lungs are the primary respiratory organ located in pairs in the chest (thorax). Lungs are spongy, air-filled organs that allow the body to take in oxygen from the air. They also help remove carbon dioxide from the body. The lungs are covered by a thin tissue layer called the pleura.

Respiration

Respiration involves three separate phases:

• Pulmonary ventilation: the exchange of air from the air from the atmosphere and the air sacs (alveoli) of the lungs.

• External exchange of gases: the diffusion of oxygen from the alveoli into the blood, and carbon dioxide diffuses out.

• Internal exchange of gases: Occurs at the tissues where oxygen diffuses from blood to cells and carbon dioxide passes from cell to the blood.


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The muscular system

The muscular systems role in the body is to produce movements of the body itself and structure within the body, to maintain posture and body position, to stabilise joints and to generate heat.

The three types of muscle in the body are:

• Cardiac: muscle in the heart

• Skeletal (voluntary): muscles are attached to bone by tendons

• Smooth (involuntary): muscles control the actions of our gut and blood vessels


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The Skeletal System

The human skeleton is made up of 206 bones These bones serve to protect and support the body and organs, interact with skeletal muscle, produce red blood cells, white blood cells and platelets.

There are four main shapes of bones:

• flat: for example, ribs

• irregular: for example, vertebrae

• short: for example, hand (carpals)

• long: for example: upper arm (humerus)

An area where two or more bones are in contact with each other is called a joint. Joints allow movement. The bones forming the joint are held together by ligaments.


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The endocrine system

The endocrine system consists of glands that influence metabolic activity on the body via hormones. Hormones are chemical messengers in the blood stream that regulate growth, blood sugar, metabolism, reproduction and sleep.

Structural Components of the Endocrine System

Summary of glands and their hormones

Gland Hormones Functions

Thyroid Thyroxine Regulates metabolism and temperature

Calcitonin Inhibits release of calcium from the bones

Parathyroid Parathyroid Hormone

Stimulates the release of calcium from the bones

Islet cells (in the pancreas)

Insulin Decreases blood sugar by promoting uptake of glucose by cells

Glucagon Increases blood sugar by stimulating breakdown of glycogen in the liver

Testes Testosterone Regulates sperm cell production and secondary sex characteristics

Ovaries Estrogen Stimulates egg maturation, controls secondary sex characteristics

Progesterone Prepares the uterus to receive a fertilised egg

Adrenal Medulla Epinephrine – fight

Norepinephrine – flight

Stimulates ‘fight or flight’ response

Adrenal cortex Glucocorticoids Part of the stress response, increase blood glucose levels and decrease immune response.

E.g.; Cortisol – helps regulate metabolism and helps your body respond to stress.

Aldosterone Regulates sodium content in blood

Pineal Gland Melatonin Sleep cycles, reproductive cycles in many mammals


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The digestive system

Otherwise known as the excretory system the digestive system takes in food, and converts it into a form that can be processed and used as energy for all the activities carried out by the body. Those particles that are unable to be digested are excreted in the form of faeces.

The digestive system performs the following vital activities:

• Ingestion (eating food)

• Digestion, further broken down to:

o mechanical breakdown of food by chewing and the action of muscles within the digestive tract, and

o chemical breakdown of food by enzymes produced at various stages of the digestive tract.


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The reproductive system

Male and female reproductive systems are remarkably different; however, their common purpose is to produce offspring.

Structural components of the male and female reproductive systems

Reproduction in humans is sexual, that is both a male and a female are required to perpetuate the species.

A male’s reproductive role is to produce male gametes called ‘sperm’ and deliver them to the female reproductive tract where fertilization can occur. Females in turn produce female gametes called ‘ova’ or eggs’.

The successful result of this fertilisation that occurs as a result of perfectly synchronised intercourse is a fertilised egg, the very first cell of a new human individual.


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The urinary system

The urinary system, also the renal system is or in some cases the excretory system, filters blood and excretes metabolic waste products.

Structural components of the Urinary System

Other regulatory functions of the kidneys include:

• The production of renin which helps regulate blood pressure and kidney function

• The production of hormone, erythropoietin, which stimulates red blood cell formation in the bone marrow

• Metabolism of vitamin D to its active and useable form


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The integumentary system

The integumentary system, the exocrine system or ‘the skin’ although only a few millimetres thick is by far the largest organ in the body. With its derivatives (sweat, oil glands, hair and nails) serves to protect, aid in temperature regulation, sensory input, excretion of water and waste products and the manufacture of vitamin D.

Structure of skin

The skin has three layers: the epidermis, dermis and a subcutaneous layer.

The first layer, the epidermis consists of largely dead squamous cells. The thickness can vary depending on age and exposure to the sun and wind. The most important function of the epidermis is to act as the first line of defence against infection.

The second layer, the dermis is connective tissue with numerous blood vessels, nerves, glands and hair follicles.

The veins and arteries are located in the deeper layer of adipose tissues and muscles. The structure of the skin allows it to stretch and for injuries to heal.


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The lymphatic system

The lymphatic system is closely interrelated to our circulatory system and is the structural basis for our immune system. Its primary function is to remove foreign substances and waste products such as dead cells, bacteria, viruses and cancer cells from blood and lymph (the fluid within the lymphatic system). This aids to help fight disease and to maintain the balance of fluid in our tissues.

Structural components of the lymphatic system

This illustration identifies the interrelationship between the circulatory system and lymphatic system.


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The Lymphatic and Circulatory systems together

The immune system

Immunity is best understood as lines of defence against effects of a particular disease agent or it’s harmful products. It is a functional system rather than an organ system. It is complex system of cells and responses that recognises something as foreign and acts to remove it. The immune system can be broken down into our innate immunity and adaptive immunity.

Innate immunity is inherited (and can vary from person to person) and adaptive or acquired immunity develops after birth- either as a natural process (exposure) or by artificial means (immunisations).

How the body protects itself from protection

Together these two innate and adaptive immunity implement three lines of defence that resist disease:

First line of defence:

• Mechanical barriers. For example, intact skin and mucous membrane

• Chemical barriers. For example, saliva, tears

• Reflexes. For example, coughing, sneezing, and vomiting

Second line of defence:

• Inflammation and fever

• Protective proteins that are produced in response to viruses and bacteria

• Natural killer cells (lymphocytes)

• Phagocytes (special white cells that eat pathogens)


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Third line of defence:

• Lymphocytes: T cells, B cells that fight specific invaders

The nervous system

The nervous system is the control and communication centre of the human body, all our thoughts, actions and emotions reflect its activity.

As conditions are constantly changing inside and outside of the body the nervous system must detect and respond to this information (stimuli) to maintain homeostasis.

The functional cells of the nervous system are called a neuron, these nerve cells transmit messages, very rapidly, from one part of the body to another. This communication occurs when our sensory receptors detect the changes, which is fed via our nerves (peripheral nervous system) which is transmitted to the spinal cord and brain (central nervous system). These electrical and chemical signals are rapid and specific and cause almost immediate responses.


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Structural components of the nervous system

Functional divisions of the nervous system.

The special senses

Smell, taste, vision, equilibrium and hearing The sensory system responds to stimuli – initiated by changes in our immediate environment as a means to protect our body. In order to detect these changes, we utilise our special senses organs, the tongue, eye, ears and nose. It also important to note that we also have general senses- which are pressure, temperature, pain and touch and positional receptors in our muscles, tendons and joints.

The sensory organs each contain different receptors that convey information through sensory neurons which is transmitted to relevant part of the nervous system.

Special receptors include chemoreceptors (chemical receptors) found in the mouth and nose, photoreceptors (light receptors) found in the eyes, and mechanoreceptors found in the ears. We also have general receptors in the skin, visceral organs, muscles, and joints.

The ear functions for both hearing and equilibrium (balance). The sensory receptors for balance are located in the inner ear. There are cilia (or hair cells) that detect movement of a thick fluid in the vestibule and semicircular canals within the inner ear.


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Structural components of the sensory organs

Relationships between different body systems

Without exception, each organ system, interacts and supports each other in order to sustain a stable healthy human body. If any one of these systems sustains damage and remains unidentified and untreated, it can greatly impact the rest of the human body. This lack of homeostasis will lead to sickness and ultimately can lead to death.

There continues to be new discoveries about how the body's systems function and work together. However, some examples of the very basic and fundamental understanding of the body's integrated working parts and organ systems are featured in the matrix below.


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Organ System Cardiovascular Respiratory Muscular Skeletal Nervous Endocrine Digestive Urinary Reproductive Integumentary

Cardiovascular

Respiratory

Oxygen moves from the lungs to the blood & carbon dioxide moves from the blood to the lungs

Muscular

The heart is largely made up of cardiac muscle

Contracting diaphragm moves air in and out of the lungs

Skeletal Bone marrow produces blood cells

Rib cage expands to help move air into lungs

Contraction and relaxation of muscles moves skeletal bones

Nervous Brain stem controls heart rate

Brain stem regulates breathing

Signals move down spinal cord to muscles

Protects brain with skull & spinal cord with vertebrae

Endocrine

Blood carries hormones throughout the body

Hormones can contribute to asthma attacks

Oxytocin causes uterine muscles to contract

Work together to maintain normal calcium level in blood

Hypothalamus controls the pituitary gland neuro-hormones

Digestive

Blood carries digested nutrients to body cells

Pharynx is passageway for air and food

Muscles churn in stomach to aid digestion

Digested forms of calcium & phosphorous help bone to repair & strengthen

The nervous system regulates the speed in which food moves throughout digestive tract

The pancreas release insulin which helps with regulation of glucose


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Organ System Cardiovascular Respiratory Muscular Skeletal Nervous Endocrine Digestive Urinary Reproductive Integumentary

Urinary

Waste products are filtered from the blood by the kidneys

Share the role of regulating acid balance

Muscle contractions are involved in emptying the bladder of urine

Kidneys produce an active form of Vitamin D to promote healthy bones

Voluntary and Involuntary nervous systems control urination

Endocrine system releases Anti Diuretic Hormone to initiate reabsorption in kidney

The urinary systems aid in excretion of wastes formed through digestion

Reproductive

Reproductive systems provide blood flow needed to maintain & sustain an erection.

Provides oxygen for the developing baby

Contraction of the uterus aid in the menstrual cycle

Pelvic ligaments stretch to accommodate birth

Reproductive hormones affect the development of the nervous system

Endocrine hormones nurture developing embryo

Good nutrition is vital for conception and a healthy pregnancy

The prostate produces fluids that lubricate the urethra for urination

Integumentary

Platelets in blood close small cuts to stop bleeding

Cells lining nostrils produce mucus to keep tissue in nose from drying out

Muscle raise hair on arms & legs when cold to help retain heat

Exposure to sun produces cholecalciferol in the skin, to maintain healthy bones

Sensory receptors on the skin feedback to the nervous system

Endocrine hormones affect action of sweat glands

Some endocrine glands are contained within the integumentary system

Both systems regulate water balance, with excessive perspiration, kidneys react to conserve water

The skin helps regulate the temperature of the scrotum to keep the testes cool

Lymphatic/ Immune

White blood cells attack pathogens such as bacteria and viruses

Respiratory passages help trap pathogens

Muscles help move lymph through lymphatic system

Bone marrow produces white blood cells

The lymphatic system responds to nervous signals to mount a defence against pathogens

Hormones directly impact inflammatory response

Fats are absorbed in the lymphatic system prior to deposit in the bloodstream

Work together to filter blood from harmful toxins

Normal immune function enable drastic hormonal changes

Skin is the first line of defence within immune system


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Homeostasis

The body has processes that it employs in order to maintain homeostasis.

Homeostasis is the body’s attempt to maintain a relatively stable internal environment while confronted with changes in the external environment. Failure to do so can result in abnormal function and disease.

Homeostasis involves negative feedback systems. The human body senses change from ideal conditions, such as a drop-in blood glucose, dehydration, blood calcium, carbon dioxide, heart rate, breathing rate, and fat deposition. The body also detects the presence of pathogens that alter homeostasis. When such factors disturb homeostasis, the body releases substances such as hormones, neurotransmitters, and antibodies to return conditions to normal.

The processes on the following pages aid in maintaining homeostasis.

Elimination of wastes from the body To survive, the human body must eliminate waste products. The process of eliminating wastes from the body is called excretion.

The kidneys, lungs, liver and skin all play important roles in the elimination of waste products.

We take in nutrients from our body through food, oxygen in the air we breathe and fluid in our drinks. Our body only uses what is required, may store some of the excess for later use and then eliminates the remainder.


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The breakdown of food and metabolic processes within the body also creates waste products that need to be eliminated.

Organ/Systems Wastes Removed

Lungs Carbon dioxide, Water, Heat

Skin Heat, Water, Salts, Urea

Digestive System Solid wastes, Water, Salts, Heat

Lymph nodes & Spleen Bacteria, dead red blood cells

Kidneys Wastes containing nitrogen, Water, Salts, Ions

Maintenance of body temperature Heat is a by-product of the many chemical processes occurring within the body. Body temperature is the balance between the amount of heat produced and the amount of heat lost by the body. Body temperature is constant despite internal and external influences and is one imperative phase of homeostasis. Factors affecting body temperature are age, weather, exercise, emotions, stress, pregnancy, the menstrual cycle and illness. The normal body temperature range for an adult is between 36.1 to 37.1 ºC.


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Many organs take part in regulation of body temperature, but central to the regulation is the hypothalamus- an area of the brain, located above the pituitary gland. The hypothalamus takes reference from the circulating blood around the brain and temperature receptors on the skin.

When too much heat is being lost, the hypothalamus can induce constriction of blood vessels in the skin, shivering of the muscles which results in increased heat production and epinephrine to increase cellular metabolism.

Conversely, with risk of overheating the hypothalamus stimulates sweat glands, cause cutaneous blood vessels to dilate and induce muscle relaxation to minimise heat production.

Homeostasis and temperature control

How does the body maintain blood pressure? Blood pressure (BP) helps move blood throughout the body. It is the pressure of the blood in the arteries as it is pumped around the body by the heart. BP does not stay the same all the time.

BP is influenced by cardiac output, resistance to blood flow and elasticity of the vessels and varies depending on situation, emotional state, activity, and relative health/disease states. In the short term, it is regulated by baroreceptors which act via the brain to influence nervous and endocrine systems. but if it exceeds the normal range, blood pressure can present serious health problems. Often people experiencing blood pressure problems will have prescribed medication to take. The main system involved in maintaining blood flow is the cardiovascular system.


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People with low blood pressure (hypotension) may experience dizziness and confusion and are at an increased risk of fails. Doctors often instruct their patients to increase fluids and salts, encourage the wearing of pressure stockings, and elevating the person’s feet as much as possible.

People with high blood pressure (hypertension) are at an increased risk of stroke, heart attack and kidney disease. They are encouraged to exercise, quit smoking and to maintain a healthy diet to assist in reaching a healthy BMI.

The systolic blood pressure (top number) is larger than the diastolic blood pressure (bottom number). A blood pressure reading under 120/80 mmHg is considered optimal. Readings over 120/80 mmHg and up to 139/89 mmHg are in the normal to high normal range.

Fluid and electrolyte balance Approximately 60% of the human body is water, and body water contains electrolytes. Electrolytes are charged particles in body fluids that help transmit electrical impulses for the proper functioning of the heart, nerves and muscles. A balance between fluids and electrolytes is necessary if cells are to survive and function normally.

The primary electrolytes found within the body include calcium, magnesium, potassium, sodium, phosphate and chloride. It is the kidneys' job to control fluid and electrolytes. If an electrolyte level is too high, the kidneys attempt to increase excretion or retain fluid to compensate.


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Extreme highs or lows of electrolytes can cause complications which may include muscle weakness or paralysis, confusion, abnormal heart rhythms or cardiac arrest.

Water for the body comes from both liquids and food. Water is lost mostly through urine, but also through evaporation from the skin when sweating, the respiratory tract and in faeces. When water intake is high, the kidneys produce larger amounts of urine to help maintain a balance. When the body is losing water, the kidneys will try to conserve water by producing a small amount of concentrated urine.


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Maintaining a healthy body

The World Health Organization (WHO) defines health as 'the state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity'. Many groups, such as the American Public Health Association, Worksite Health Promotion, and the National Wellness Association, have expanded the concept of health further to encompass wellness: the spiritual, social, mental, physical, and occupational needs for one to live life to the fullest.

Recognise and promote ways to support healthy functioning of the body The personal choices we make in life are important to health outcomes. We attempt to prevent disease by reducing stress, maintaining good nutrition, exercising, having routine dental and physical screenings (for cholesterol levels and blood pressure, for example).

Many people wait until they are ill or unwell before seeking medical advice or help. Health care professionals recognise that it is easier and more cost effective to help a person maintain their good health than it is to treat a person who is already unwell.

As a health care worker, you play an active role in assisting a person to maintain a healthy body. To carry this out effectively, it is necessary you understand, and are able to communicate the principles of maintaining a healthy body.

Diet

The basic life needs that must be fulfilled are:

• Food and water

• Shelter and safety

• Belonging and self-actualisation

Whilst food is a necessity, the type and amount of food consumed will have very definite effects on health.

A healthy diet is one that has sufficient nutrients (proteins, carbohydrates, fats, vitamins and minerals) and is maintained by eating appropriate amounts from the range of food groups.

For more information regarding the current guidelines on nutrition and food groups visit:

https://www.eatforhealth.gov.au/food-essentials/five-food-groups

Physical activity

The health benefits of regular exercise and physical activity are hard to ignore. There are two types of exercise: passive and active. Active exercise is a motion imparted to a part by voluntary contraction and relaxation of its controlling muscles.

https://www.eatforhealth.gov.au/food-essentials/five-food-groups


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Passive exercise motion is imparted to a segment of the body by another individual, machine, or other outside force, or produced by voluntary effort of another segment of the person’s own body. The benefits of regular exercise are:

• maintaining healthy weight

• improved mental health

• improved energy levels

Effective hygiene and cleanliness

Hygiene refers to practices associated with ensuring good health and cleanliness. Such practices vary widely and what is considered acceptable in one culture might be unacceptable in another. In medical contexts, however, the hygiene refers to the maintenance of health and healthy living. The term appears in phrases such as personal hygiene, domestic hygiene, dental hygiene and occupational hygiene, and is frequently used in public health.

Food hygiene

Food-borne illnesses such as food poisoning, can be debilitating and can, in extreme cases, cause death. Patients whose immune systems are compromised (the young, aged and those who are frail or ill) are particularly vulnerable to food-borne infections. Food and beverages can be contaminated by several disease-causing organisms such as viruses, bacteria, moulds and yeasts. They can also be contaminated by chemicals or by physical contaminants (glass, metal pieces etc.).

Oral hygiene

Current research is showing direct links between chronically infected gums and coronary heart disease. Oral hygiene is the practice of keeping the mouth and teeth clean to prevent dental problems, most commonly:

• dental cavities

• gingivitis, or

• other pathological conditions

Good oral hygiene is required for healing and regeneration of the oral tissues.

Rest/sleep

Ensure you have sufficient sleep and allow time for relaxation and recreation. Sleep is a natural state of bodily rest. Regular and sufficient sleep is essential for survival and for the maintenance of a healthy body. The adult human body requires between six and eight hours of sleep per night, but bear in mind that not everyone is the same. Sufficient sleep benefits alertness, memory and problem solving and overall health. It helps the body’s metabolic processes and contributes to psychological health.

Study Guide - LTT

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