Health and Social Care - Unit 4

name of red blood cells

erythrocytes

name of white blood cells

leucocytes

plasma

the liquid part of blood. It's mostly water but contains a weak solution of salts, glucose, amino acids, vitamins, urea, proteins and fats (55%)

white blood cells

involved in the immune system - help destroy bacteria (<1%). It consists of Neutrophils, Lymphocytes, and Monocytes

neutrophils

B-type cells produce antibodies

Lymphocytes

T-type cells destroy viruses and cancer cells

monocytes

removes dead cells and bacteria

red blood cells

carry oxygen and some carbon dioxide

platelets

triggers blood clotting. without it you would bleed to death (<1%)

lipoproteins

proteins that carry elements that cant dissolve in water, e.g. fats

pathogen

disease causing organisms, like bacteria, parasites and viruses

antigens

they form antibodies

antibodies

lock onto specific chemicals in the walls of the bacteria and parasites, immobilising them and making them targets for the monocytes that then kill them and break them down

coagulation

a chain reaction that converts the soluble blood protein (fibrinogen) into an insoluble form (fibrin), that forms a net structure, trapping platelets and erythrocytes to form a clot. this reaction is set off by tiny cell fragments from the bone marrow, called platelets, are exposed to air or foreign material

double circulatory system (double pump)

the heart pumps blood through two circuits, the pulmonary and systemic

systemic circuit

left side of heart receives oxygenated blood from lungs and pumps it around the body

pulmonary circuit

right side of heart receives deoxygenated blood from the body and pumps it to the lungs

myogenic

the heart muscle is myogenic - it can beat automatically without stimulation by nerves

cardiac cycle

the co-ordinated flow of blood through the heart. it takes place on average 70 times per minute.

systole

ventricles contract, pumping blood out

diastole

heart relaxes and the atria fill with blood

the SA node (sino-atrial node)

coordinates rhythm of heart and ensures both atria contract simultaneously by passing an electrical current through the atria

AV node (atrial-ventricular)

at the bottom of the right atrium. it slows the electrical impulses it receives from the SA node to allow ventricles to fill with blood

Purkyne fibres

carry current down the middle of the ventricles to the base of the heart. this allows the bottom of the heart to contract first, resulting in an upwards, squeezing action, forcing blood out into arteries

ECG (electrocardiogram)

shows the electrical signal generated by the SA node as it travels through the atria, the AV node and the ventricles. electrodes are attached to the chest and fed to a computer screen. the activity of the heart is shown in waves or spikes

p wave

a small blip - shows the moment when atria are both contracting

QRS wave

a bigger spike after a p wave that shows the ventricles contracting (systole)

T wave

a smaller wave - shows the ventricles relaxing (diastole)

arteries

- carrys oxygenated blood away from the heart

- walls are thick, elastic and muscular as blood is under high pressure

- blood flows in pulses (arteries expand and recoil)

- small internal diameter

capillaries

- walls are one cell thick

- they are microscopic

- they surround and interweave between cells and tissues

- they supply tissues with oxygen and nutrients and remove waste products like carbon dioxide

veins

- carry deoxygenated blood towards the heart

- walls are thin with little muscle as blood is under low pressure

- contain valves to prevent backflow

- large internal diameter

- are often between muscles so movements help squeeze blood along

osmosis

the movement of water through a semi-permeable membrane from a less concentrated solution to a more concentrated one

osmotic pressure

pressure that must be applied to prevent osmotic movement across a selectively permeable membrane

lymph

watery fluid drained by the lymphatic system

formed from plasma

contains white blood cells

involved in the removal of wastes and infectious organisms from tissues

tissue fluid

fluid between body cells

carries nutrients and oxygen to tissue cells

is formed from filtering of blood from capillaries due to hydrostatic pressure

blood plasma

liquid component of blood

contains plasma proteins, which have roles in blood clotting and supporting the immune system

osmotic regulation

osmotic regulation

control of the water content of the body, avoiding too much water entering or leaving the cells

lymphatic system

a drainage and filtrations system

it removes excess fluid from body tissues

it absorbs fatty acids and transports fat into the bloodstream to be absorbed in the small intestine

it produces white blood cells (which produce antibodies)

lymph nodes

swellings along the lymphatic system. they store and develop lymphocytes that screen the returning tissue fluid or lymph for pathogens, destroying any that are found. when fighting an infection these nodes swell so we often refer to our glans swelling

hydrostatic pressure

pressure from heart contractions that forces water and dissolved substances in plasma out through capillary walls into surrounding tissues, forming tissue fluid

hypertension

high blood pressure

Systolic pressure

Higher number - the force at which your heart pumps blood around your body

Diastolic pressure

Lower number - the resistance of the blood flow in the blood vessels

coronary heart disease

issues concearning the coronary arteries that supply the heart muscle itself with nutrients and oxygen

endothelium

a smooth layer that protects the inner surface of the artery. it allows smooth and interrupted blood flow to the heart muscle. smoking and high blood pressure (caused by obesity and drinking) damage this layer.

atheroma

gunge that gradually distends the wall, reducing the space inside the artery and obstructing blood flow to the heart

angina

a condition caused when the cells beyond the obstruction in the arteries get less oxygen, resulting in pain on exertion

angiogram

a type of x-ray that involves a dye visible in x-ray photographs that is injected into the blood system so that narrowing of coronary arteries can be seen

angioplasty

a microscopic deflated balloon is passed into a narrowed artery and inflated, pushing the artery open. sometimes a microscopic mesh tube or stent is inserted at the same time, keeping the artery open for longer

coronary bypass

using a piece of artery from the chest to bypass or bridge a blocked region of coronary artery, allowing blood to flow beyond the blockage

larynx

connects the back of the nose and the trachea, forming an air passage to the lungs

trachea, bronchi, bronchioles

the trachea starts at the back of the throat (pharynx) and divides into 2 bronchi, each leading into one of the lungs where they divide into bronchioles. the trachea and bronchi have rings of cartilage along their length to stop them collapsing

Alveoli

sacs found in clusters at the end of the bronchioles. each alveolus is surrounded by a capillary network where oxygen and carbon dioxide are exchanged through the alveolar membrane

mucus

are in the tube - its a sticky slimy fluid that traps dirt particles and bacteria breathed in

cilia

are in the tube - they're hair-like extensions that beat backwards and forwards to move the mucus and trapped particles back up the throat, where you swallow them

diaphragm

a muscle attached to the lower ribs that separates the chest from the abdomen

intercostal muscles

muscles found between the ribs

breathing

movement of air in and out of the lungs

inspiration

breathing in - to deliver oxygen into the body

expiration

breathing out - to remove carbon dioxide

pleural membranes

they are moist and slippery, and have 2 layers of thin membranes with a thin film of liquid between them. this lubricates the surface so the 2 layers slide over each other, allowing the lungs to move easily in the chest cavity. this means they move with the chest wall as breathing occurs

the role of the diaphragm and intercostal muscles - when breathing in...

1) diaphragm moves down

2) intercostal muscles contract

3) rib cage moves up and out

the role of the diaphragm and intercostal muscles - when breathing out...

1) diaphragm moves up

2) intercostal muscles relax

3) rib cage moves down and in

gaseous exchange

oxygen enters the blood and carbon dioxide is removed from it

diffusion

the movement of molecules from an area of high to low concentration

cellular respiration

a complex set of chemical reactions and processes that take place in the mitochondria to convert biochemical energy from nutrients into ATP and then to release waste products

glucose

a sugar supplied by food, which gives us energy

ATP

formed from ADP using energy released from the breakdown of glucose.

its a high energy molecule found in every cell, which stores and supplies the cell with energy

aerobic respiration

with oxygen

glucose + oxygen = carbon dioxide + water

anaerobic respiration

without oxygen

glucose = pyruvic acid = lactic acid

lactic acid is changed back into pyruvic acid when oxygen becomes available

glycosis

happens in the cytoplasm. it breaks down glucose and forms pyruvic acid, with the production of 2 molecules of ATP

Krebs cycle

where pyruvic acid supplies energy to cells when oxygen is present (aerobic respiration)

if no oxygen is present (anaerobic respiration), it produces lactic acid

fatigue

tiredness caused by lactic acid

oxygen debt

occurs when anaerobic respiration is used to gain extra ATP.

when exercise is finished, you need to get rid of lactic acid by breaking it down in the mitochondria using oxygen

asthma

triggers cause the bronchii to become inflamed and narrow as the muscles contract. there's an increase in mucus production. this causes wheezing, shortness of breath, a tight chest and a cough. severe asthma attacks reduce the amount of air reaching the lungs. it can lead to a cardiac arrest. triggers may be cigarette smoke, atmospheric pollution, cold air, dust, animal fur, dust mites, pollen, exercise, stress and laughter

emphysema

a condition in a group of respiratory illnesses called COPD. it's mainly caused by long-term smoking. chemicals in smoke paralyse the lung-cleaning cilia and eventually kill them, leading to a build-up of mucus and, with pathogens trapped in the lungs, increasing infections. continued exposure to chemicals, inflammation and infections damage the alveoli and bronchioles. this decreases the efficiency of the lungs as these tissues collapse. it becomes difficult to obtain oxygen, so exertion results in breathlessness and coughing

cystic fibrosis

present from birth. caused by a defective gene on one chromosome (the parents each carried one copy of the defective gene). the CFTR gene makes a defective form of a protein that should move water and salt in and out of cells. this means people with CF produce thick and sticky mucus which block bronchioles and restrict movement of respiratory gases in and out of the lungs. this mucus also traps bacteria, resulting in coughing and repeated chest infections. mucus is also produced in the digestive and reproductive systems, impairing their function, resulting in poor weight gain, abnormal stools and reducing fertility. CF causes increased salt in sweat. there is no cure

Nebuliser

a mouthpiece or facemask that introduces medication to the lungs as a fine spray

spirometer

equipment that measures the volume of the lungs and how much air can be exchanged per breath

buccal cavity (mouth)

food enters and is chewed to break it down

salivary glands

produce saliva to moisten food to make it easier to swallow

epiglottis

covers opening of windpipe when swallowing

Oesophagus (gullet)

tube connecting the throat and stomach

peristalsis

the action of food being squeezed by muscles to help it move down the oesophagus

stomach

muscular walls churn food to break it up. it produces hydrochloric acid and enzymes to digest food

another name for the small intestine

the duodenum

small intestine

food is now called chyme. its chemically altered by fluids from the liver and bile from the pancreas. it is lined with villi, which increases the surface area on the wall, which helps the absorption of nutrients into the bloodstream

another name for the large intestine

the colon

large intestine

reabsorbs fluids and processes waste products

rectum

stored faces

anus

faeces are expelled

mechanical digestion

food is physically broken so it's small enough to swallow

chemical digestion

nutrients are broken down by enzymes to smaller molecules that can be absorbed into blood and used by cells

bile

produced by the liver and stored in the gallbladder until the body needs it. it helps absorb fat into the bloodstream. it enters the small intestine through the bile duct. it emulsifies fats and neutralises stomach acid

absorption

how nutrients extracted from food are absorbed into the bloodstream. this occurs in the small intestine

villi

finger-like projections - increase the surface area of the small intestine wall to enable efficient absorption

the lacteal

lymphatic capillaries that absorb dietary fats in the villi of the small intestine

assimilation

the movement of digested food molecules into the cells of the body where they are used, so that they become part of those cells

IBS

symptoms occur when the muscle of the gut alter their normal rhythms. results include constipation and diarrhoea, abdominal pain, a bloated feeling, indigestion and increased flatulence or wind. causes may be dietary (alcohol, carbonated drinks, chocolate, fried and processed food) and stress

gallstones

form in gallbladder due to an imbalance in the composition of bile. high levels of cholesterol and bilirubin (produced by liver) result in crystals that grow to form gallstones ranging in size from specks to pebbles. risk factors include being female, over 40, have existing liver damage, IBS and a family history of gallstones.