B2.1 The Human Anatomical System - The routes of Entry and Defensive Responses Flashcards
Explain the characteristic of the respiratory system
air enters the nose – nasal cavity-pharynx trachea-thoraxic cavity divides into 2 bronchi left & right lungs. Each lungs the bronchi branches into bronchioles which branches to smaller tubes into alveoli air sacks. Its in the alveoli the gas exchange. During respiration oxygen diffuses across the thin membranes of the alveoli into bloodstreams & at same time CO2 diffuses out of the bloodstream into the air in the alveoli & is exhaled
Explain the characteristics of the Digestive system
the function is to digest and absorption of food stuffs which are dealt in four stages. Ingestion – through the mouth mastication and swalling.
Digestion – the breakdown of food by enzymes in stomach
Absorption – of breakdown products of digestion in small & lg intestine.
Excretion – of undigested food and waste through anus
Explain the Nervous system
is divided into two main parts the central and the peripheral. Central nervous system comprises of brain and spine and the peripheral consists of motor/ movement & sensory nerves
What are the 3 essential components of the circulatory system?
Circulatory system – consists of heart, blood vessels and blood (cells). Blood cells consist of red cells – haemoglobins that carry oxygen and white cells that form the main defensive system.
The heart – muscular sack situated in the chest cavity. It is divided by a septum into right and left sides. Each side is divided into an upper and lower chamber: the atrium which receives blood and ventricle that distributes blood into the attached blood vessels. The beat of the heart is controlled by the nerve
Blood vessel – consist of arteries capillaries and veins. Arteries carry oxygenated blood away from the heart; capillaries form the very fine tubes that carry blood into close proximity to cells & tissue; Veins carry blood from capillaries back to the heart usually deoxygenated. 20sec for blood to flow around the entire body. Deoxygenated blood return to the heart & pumped to the lungs.
Describe the composition of the skin
Epidermis - the outer layer of the skin.
Dermis - the layer of the skin just beneath the epidermis.
Subcutaneous tissue - fatty tissue located under the dermis
Explain the structure of the dermis (5)
blood vessels - Tubes that carry blood as it circulates. Arteries bring oxygenated blood from the heart and lungs; veins return oxygen-depleted blood back to the heart and lungs.Sebaceous gland - a small, sack-shaped gland that releases oily (fatty) liquids onto the hair follicle (the oil lubricated and softens the skin). These glands are located in the dermis, usually next to hair follicles.
Sweat gland - a tube-shaped gland that produces perspiration (sweat). The gland is located in the epidermis; it releases sweat onto the skin.
hair follicle - a tube-shaped sheath that surrounds the part of the hair that is under the skin. It is located in the epidermis and the dermis. The hair is nourished by the follicle at its base (this is also where the hair grows).
Heat and Cold receptors- Detect heat and cold and pass info via nerves to central nervous system.
Explain the function of the Nose
Humidify and warm the air as it inhales in the respiratory system
provides sense of smell during inhalation the odour molecules attach to nerve cells embedded in the mucous membranes which are then stimulated sending nerve pulses to the brain. The sense of smell is useful to give warning smells of CO2, Carbon monoxide etc. Its worth mentioning some hazardous substances are able to destroy the nerve cells responsible to generate odour signs such as H2S
list the routes of entry (4)
Inhalation, Skin Contact, Ingestion and Other routes (aspiration, Ear and by the mucous membrane of the eye)
Explain the routes and methods of entry
Routes of Entry:
Inhalation - is the most frequent and significant route of entry because the lungs are so vulnerable. Lungs has a massive area for oxygen to be absorbed from inhaled air to supply the body. The alveoli is close to the bloodstream to allow the diffusion of oxygen which means toxic substance will be passed to the blood stream and other organs, typical within 30 to 60 seconds.
Skin contact is the second most vulnerable area, as it can come in contact with liquid solid or gaseous toxic substance (epidermis layers of protection, skin is waterproof and require long contact.
Ingestion – the gastrointestinal is the least vulnerable because the possibility of liquids or solid toxic being ingested is limited
Other routes – aspiration, mucous membrane of the eye-absorption, ear
Physical Forms
Solids (dust, massive form (Lead) Fibres (asbestos), Fumes (welding)
Liquids – massive form, mists, droplets
Gases – vapour
List the effects when hazardous substances gain entry to the body
When enter to body it can have a:
local effect – only to the local area
systematic effect affects parts of organs or parts of the body (Lead inhaled to lungs and affecting the liver
Target organs & target systems (lead inhaled affecting the Liver)
The body defence mechanism against a foreign body are called immune system. Describe the two defence mechanism to protect the body from attack and damage
Defence response of body against foreign agents:
Innate Response – response we born with
Adaptive Response – developed when invade the system and a memory is built for further future defences - antibodies. (i.e flu)
The respiratory system has a series of defence to combat dust inhalation. Outline the series of defense (5)
- Nasal filtration so called nasal Hair – filter lg particles 10µm
- Sneeze reflex - Coughing & sneezing – forceful ejection
- The mucociliary escalator – substance are trapped by mucus and propelled towards the nose and throat and swallowed or spat out.
- Macrophages – particles of 0.5 -7µm entering the alveoli will be attacked y the Macrophages, which are white cells that are present on body tissue and destroy foreign particles by ingesting and producing enzymes and absorb the digested remain.
- Inflammatory response – white cells are called to the infected area, if left untreated it can result in disease (i.e dust flour)
