diff --git a/Grade 10/Science/SNC2DZ/Unit 2: Biology.md b/Grade 10/Science/SNC2DZ/Unit 2: Biology.md index 24594cc..a0672c8 100644 --- a/Grade 10/Science/SNC2DZ/Unit 2: Biology.md +++ b/Grade 10/Science/SNC2DZ/Unit 2: Biology.md @@ -364,7 +364,7 @@ A person contains roughly 100 trillion cells - Villi contain capillaries and absorbing and goblet cells - Absorbing cells caintain microvilli, which absorb nutrients via diffusion -### Respiratory system +## Respiratory system - Exchanges oxygen gas and carbon dioxide gas between red blood cells and the surrounding air, which is required for cellular respiration - Diaphragm contracts to lower itself, causing the rib cage to rise, which increases lung volume, which subsequently causes pressure to decrease and air to rush in to the lungs - Diaphragm relaxes to return everything to its normal position @@ -377,4 +377,93 @@ A person contains roughly 100 trillion cells - Nose hairs and mucous trap debris which is swept out by cilia - Alveoli (singular "alveolus") epithelial tissue is one cell thick - Surrounded with capillaries which exchange gases via diffusion - - Trachea -> 2 bronchi -> bronchioles -> alveoli \ No newline at end of file + - Trachea -> 2 bronchi -> bronchioles -> alveoli + - Gas exchange + - Swapping of carbon dioxide and oxygen gas between the bloodstream and the environment (e.g., red blood cells and alveoli) + - A large surface area, thin membrane, and moisture are all required for optimal gas exchange + - Alternate gas exchange systems include + - Fish using a constant water flow forcing dissolved oxygen through their gills + - Gills stick together out of water, resulting in suffocation + - Frogs use lungs on land, but can also perform gas exchange underwater using their skin + +## Circulatory system + + + + - Interacts with literally every other system + - Carries oxygen and nutrients to cells, carries carbon dioxide and waste away + +### Components + - Composed of heart, arteries, veins, and capillaries + - `Arteries` flow **away** from the heart + - Made of **thick** muscle layers and elastic connective tissue + - Muscle layers must withstand and **maintain** higher blood pressure throughout body due to proximity to heart + - May `vasoconstrict` or `vasodilate` to increase or restrict blood flow, for example, to blush or to pale, respectively + - `Veins` flow **to** the heart + - Made of **thin** muscle layers and elastic connective tissue + - Carries low pressure blood with valves to ensure one-way flow + - Blood moves by movement of skeletal muscles pushing blood + - `Capillaries` are one cell thick + - They transition between arteries and veins + - Blood cells are forced to go in single file + - Present, amongst other places, in alveoli and villi + - The `heart` pumps blood throughout the body + - Has one-way valves + - Has four chambers, two `atria` (sing. `atrium`) and two `ventricles` + - Blood is returned to atria which push them to ventricles which push them out of the heart + - **Right** side of heart receives and sends **deoxygenated** blood **to** lungs + - **Left** side of heart receives and sends **oxygenated** blood **from** lungs + - Invertebrate circulatory systems are either **open** or **closed** (douse everything with blood then collect or use vessels like we do, respectively) + - Most invertebrates have an open circulatory system + +### Mycardial infarction + - Also known as **heart attack** + - When `atherosclerosis` occurs in `coronary arteries` (when fatty plaque deposits build up in arteries feeding the heart) + - If clots break open a larger clot forms over it + - This repeats until the artery is completely blocked, leading to death of cardiac muscle cells + - Caused by lifestyle choices, although predisposition can be increased due to genes + +### Blood + - Composed of red blood cells, white blood cells, platelets, and plasma + - `Red blood cells`: Biconcave discs carrying oxygen and carbon dioxide to and from cells, respectively, using `hemoglobin` + - Denucleated, instead packing as much hemoglobin as possible inside + - Hemoglobin and oxygen give them their colour + - `White blood cells`: Part of the immune system, they neutralise and remove foreign threats + - Can make antibodies + - Can engulf and kill pathogens + - 700:1 ratio of red blood cells to white blood cells + - `Plasma`: Clear fluid made of 90% water filled with proteins and dissolved nutrients + - `Platelets`: Irregular colourless "bodies" that form **fibrous** clots + +## Immune system + - `Pathogens`: any**thing** that cause disease + - Pathogen waste can be toxic which cause symptoms of disease + - Passive defense + - Skin - physical barrier + - Sweat/tears - `lysozymes` kill bacteria + - Stomach acid - it's acid dangit acid kills things + - Beneficial bacteria overpopulate surfaces to prevent harmful bacteria from settling + - Adaptive defense + - `White blood cells`: For the sake of G10, divided into two subtypes: + - Cells that engulf and consume bodies (`phagocytes`, e.g., macrophages) + - Cells that produce antibodies (`plasma B cells`, i.e., plasma B cells) + - `Antibodies`: Secreted proteins that stick to a specific molecule found on pathogens + - Clumps pathogens together for simple cleanup and prevents them from spreading + - Covers and prevents toxins from reacting + - Acts as a flag for phagocytes to destroy marked pathogen or toxin + - Acquired immunity + - After initial immune response, antibodies are still produced for that type of pathogen + - Once pathogen is detected again, "memory cells" reactivate and kill things faster + - Much faster than initial response, typically resulting in no symptoms + - This is why you generally can never be sick from the same pathogen twice + - Pathogens mutate (e.g., influenza) so that they are no longer recognisable by antibodies + - `Vaccination`: Injecting a small amount of a **dead/weakened** version of pathogen giving acquired immunity without actually getting disease + - There may be mild side effects + - `Boosters` are required for some vaccines as "memory" fades over time (e.g., tetanus) + - `Herd immunity`: When enough of the population (90% in general) is immune to a disease, drastically reducing rate of disease even amongst those not immune + - Those who cannot be vaccinated for whatever reason are protected due to a far lower chance of encountering the disease itself + - Prevention (vaccine) > cure (treatment) + - Chance of disease from the vaccine are far lower than chance of death or serious infection from a pathogen + - Vaccines do not cause autism or seizures, but may act as a trigger for the latter due to genetics + +## Musculoskeletal system \ No newline at end of file