Anatomy & Physiology Part 1

Anatomy & Physiology (Cells, Tissue Classification, Blood, & Respiratory System)

Anatomy  The study of the structure of animals and plants

Physiology  Is the function and activity of living organisms

Cells  Sometimes called the building block of life  Cells take nutrients from food and convert it to energy in order to function  Groups of cells together form tissue  When they specialise to perform specific functions, they are called organs

of 13 G ms anatomy student notes Cells are made up of different components:

Cytoplasm

Houses organelles Protects nucleus Nucleus

Control centre Brain of the cell

Organelles Cell membrane Perform specific Protective layer functions like our organs.

of 13 G ms anatomy student notes Types of cells

1. Epithelial cells  Composition of epithelium.  Skin (covering outer body), epidermis (outer thin layer of the skin), glands.  Mucous membrane covered by epithelium, lines oral cavity and tubular organs.

2. Connective  Basically these cells connect one tissue to another  Bone, blood, ligaments, tendons, cartilage, fat.

3. Muscle  Produces movement and generates heat for the body.  Its function is to produce force and cause motion

4. Nervous  Initiates & carries electrical impulses and the body’s instructions.  Tells Glands to secrete chemicals, for muscles to move etc

of 13 G ms anatomy student notes Blood  Red sticky fluid that circulates through the heart and blood vessels  Blood vessels are veins, arteries and capillaries  Body contains approx 5 - 6 litres of blood  Maintains a constant temperature of 37 degrees ˚c  Supplies O2 and nutrients to tissues  Removes waste products such as carbon dioxide  Houses repair mechanism of body  Regulates body’s pH  Defends against invading micro-organisms  Blood is made up of 55% Plasma (liquid) and 45% cells  The cells are Red, white and platelets

Red Blood Cells  Correct name is Erythrocytes  Function of erythrocytes is to carry Oxygen to the body’s tissues & organs and to carry waste away  Colour is red because it contains haemoglobin  Haemoglobin is a protein that contains iron  Shortage of haemoglobin in cells causes Anaemia

of 13 G ms anatomy student notes White Blood Cells  Correct name is Leukocytes  Function is to defend the body against infection, disease & foreign materials  A deficiency in white blood cells lowers a person’s immunity and leaves body open to infection

Platelets  Correct name is Thrombocytes  Function is to repair wounds by forming blood clots (coagulation)  Thrombocytes start to stick to the edges of the wound and are held together by fibrin which is a constituent of plasma (platelet plug)  Haemophilia is a genetic illness which means the patient’s blood does not clot effectively

Plasma  Liquid component of blood  It is a straw coloured liquid (90% water, 7% proteins, 1% salts)  It’s function is to transport cells, proteins, amino acids, hormones, wastes, antibodies and nutrients  It maintains the pH of blood  Contains Fibrin which helps coagulation by creating a mesh which holds the platelet plug together

of 13 G ms anatomy student notes Respiration

 This is the process that happens when we breathe in and out (inspiration and expiration)  As the body’s cells use the oxygen we breath in (inhale), there is a waste by product that is breathed out (exhale), called Carbon Dioxide  An average adult has a normal resting respiration rate of roughly 12 -20 breaths per minute. A child has a rate of 20- 30bpm.

The Functions of the Respiratory System  To circulate oxygen round the body and remove waste co2  To moisten and warm the air we inhale  It detects smells  Produces sounds used for speech  Protects internal organs from foreign objects

The respiratory system  Divided into 2: upper respiratory tract & lower respiratory tract.

of 13 G ms anatomy student notes Upper respiratory tract

of 13 G ms anatomy student notes Lower respiratory tract

of 13 G ms anatomy student notes Maintaining Airway Cartilage  Ensures airway is always open and provides protection Mucus  Airways is covered in mucus which collects dust and dirt  Contaminated mucus is propelled away from the respiratory system by the cilia back into the nose / mouth and expelled from the body Protective Mechanisms  Coughing forcibly expels any foreign objects from the Larynx, trachea and bronchi  Sneezing forcibly expels any foreign objects from the nose but this also spreads diseases by producing infectious droplets  Cilia is the microscopic hair lining in the respiratory tract which sweeps away foreign bodies such as dust  Mucous coating warms the air as it enters nasal cavity. This mucous is replaced at the back third of nose every 15 minutes to remove foreign bodies. Artificial Respiration (BLS)  If natural breathing stops it may be restored by artificially inflating the lungs  Can be achieved through compression and breaths, ambu bag, pocket mask and oxygen

of 13 G ms anatomy student notes Heart and circulation

The Heart  Muscular organ that lies in the thoracic (chest) cavity  Lies between the lungs and behind the sternum (middle of the rib cage)  Function of the heart is to pump blood round the body, providing oxygenated blood to all body’s tissues & organs  Size of a fist and weighs 9 ounces  There a 3 layers of muscle in the heart: pericardium, myocardium & endocardium.

Blood vessels  Blood vessels allow blood to enter and leave the heart  Blood vessels include Veins, Arteries & Capillaries  Veins carry blood to the heart. They are elastic and low pressure  Arteries carry blood away from heart to body. These are high pressure and have thick muscular walls. They expand and relax under the pressure of the blood moving through it. This is how blood pressure is measured.  Capillaries are a fine network of vessels that extend from veins and arteries and enter into tissues  These deliver nutrients and remove waste from tissues.

of 13 G ms anatomy student notes The heart

of 13 G ms anatomy student notes Circulation

of 13 G ms anatomy student notes Heart Disease  Pericarditis is inflammation of the outer layer of the heart. Can be caused by - Viral infection, Bacterial infection, Fungal

 Endocarditis is inflammation of the inner layer of the heart. This disease damages the valves of the heart. As the valves of the heart do not actually receive any blood supply of their own, Defence mechanisms (such as white blood cells) cannot enter. Bacteraemia is where bacterial infection takes hold.

 Myocarditis Is inflammation of the the muscular part of the heart. It is generally due to infection (viral or bacterial).

 Angina pectoris is commonly known as angina. Chest pain due to lack of blood to the heart muscle, narrowing of the arteries to arterio sclerosis (hardening)

 Myocardial Infarction, more commonly known as a heart attack. Blockage of arteries due to blood clot (thrombosis), angina or coronary disease leads to coronary thrombosis. Lack of blood supply to myocardium will cause death of muscle fibres

of 13 G ms anatomy student notes