Science Review 4 Quizlet PDF

Hierarchy of tissue types Levels of organization in the human body: Cell → tissues → organ → organ system → organism Tissue: Specialized cells are organized into tissues Tissue: A group of similar cell type that perform a common function Organ: A structure that is made of different tissues working...

Hierarchy of tissue types Levels of organization in the human body: Cell → tissues → organ → organ system → organism Tissue: Specialized cells are organized into tissues Tissue: A group of similar cell type that perform a common function Organ: A structure that is made of different tissues working together to do a complex body function Organ system: A system of one of more highly specialized organ and structures that work together to do basic functions (to get nutrients and get rid of wastes to sense and respond to the environment, to grow and repair damage, and to reproduced) Organism: A organism has several organ systems that function together Animal tissues 4 Main tissues types: 1. Epithelial ○ Thin sheets of tightly packed cells covering surfaces and lining internal organs Ex: Skin, lining of the digestive system Functions: Protects structures Lines (body cavities & outer surface of body) Forms glands (produce hormones, enzymes and sweat) Types of epithelial tissue: Simple epithelium: a single cell layer Stratified epithelium: more than one layer of cells 2. Connective ○ Various types of cells held together by a matrix (a liquid - blood, a solid - bone, or a gel) Functions: Supports structures Protects structures Forms blood Stores fat Fills empty space Ligament, cartilage, tendons Types: Loose connective tissue Ex: blood cells, areolar connective tissue (layer under skin), adipose tissue (fat tissue around kidneys) Dense connective tissue Ex: Dense regular connective tissues (tendons & ligaments) → fibers are arranged in the same direction, Cartilage - cells are in a firm matrix, Hardest connective tissue (bones) - cells are hard within the matrix 3. Muscle ○ Bundles of long cells (muscle fibers) that contain specialized proteins that can shorten or contract ○ Contains a fair amount of mitochondria → since mitochondria produces energy & energy is needed to move the muscles Ex: Heart, intestine, blood vessels Functions: Allows body movement Moves food, blood, waste through the body Surrounds digestive system Types: Skeletal muscle Cardiac muscle Smooth muscle 4. Nervous ○ Long thin cells with the branches at the ends that conduct electrical impulses Functions: Responds to stimuli Communicate within the body Coordinate body functions  Nervous tissues in the brain, spinal cord & nerves Digestive system: Types of digestive systems: 1. Bag system Found in organisms like jellyfish and coral This type of digestive system has one opening ○ Meaning that food and waste enter and exit from the same place Enzymes are secreted into this cavity to chemically break down the food 2. Tube system Found in animals like humans, worms and cows. This digestive system has an opening at both ends of a long tube (one entrance and one exit! 3. Ruminants (eg Cows) An animal that digests plant-based foods in a series of digestive chambers Four stages of tube digestion 1. Ingestion - food is taken in 2. Digestion - physical and chemical breakdown of food 3. Absorption - import of nutrients into the bloodstream 4. Egestion/defecation - removal of undigested waste materials Mouth:  Site of ingestion and chewing Both physical (mechanical) and chemical digestion occurs here (tongue, teeth, saliva, enzymes) Esophagus: Long tube of muscle tissue that squeezes the food down to the stomach, using wave-like smooth muscle contractions called peristalsis. Connects mouth to stomach In the stomach: A muscular organ that mechanically mixes the food with hydrochloric acid, and some digestive enzymes. Food is liquefied in preparation for further digestion later on. Acid is used to ensure bacteria and other microorganisms are killed. The intestines: The main site of: Chemical digestion Absorption of nutrients (SMALL INT.) & water (LARGE INT.) into the blood Formation and egestion (excretion) of feces To do this, it has several tissue types: Muscles to continue peristalsis Blood vessels to collect nutrients Highly folded and specialized epithelium → The massive surface area maximizes absorption Accessory organs: are organs that aid digestion but never come in contact with your food: Liver: produces bile (which helps dissolve fats) Gall-bladder: stores bile Pancreas produces most of the enzymes needed for chemical digestion and insulin. Diabetes is when you have problems with insulin levels. * all of these products are added to the food at the beginning of the intestines In the stomach: Foveolar cells or surface mucous cells (another example of cell specialization): They produce and secrete mucus from the Golgi, which lubricates the inside of the stomach and intestines, and protects the cells of your stomach from the acid. In the intestines, goblet cells produce mucus. Parietal cells secrete hydrochloric acid to destroy pathogens and aid in chemical digestion. In the intestines: Inner folds are covered with many villi (bumps) Each villus (singular) is filled with blood vessels Epithelial cells: lined with absorbing cells and goblet cells Microvilli are highly folded cell membranes, allowing for the absorption and transportation of nutrients into bloodstream ○ Microvilli: Absorbs nutrients then transports them in the bloodstream When Digestion Goes Wrong What diseases/disorders can you think of that have to do with the digestive tract? Acid reflux ○ Heartburn ○ Celiac ○ Indigestion ○ Ulcers ○ Diarrhea ○ Constipation ○ Lactose intolerance Key Words: Digestion Absorption Villi Esophagus Stomach Intestines Accessory Organs The Circulatory System The circulatory system is a continuous network of tubes (blood vessels) that runs throughout the body and functions to carry O2 and nutrients TO all the body’s cells, while CO2 and cellular wastes are carried AWAY from body’s cells. Diagram of components: Components: The heart has four muscular chambers separated by one-way valves that prevent blood from moving backwards. The RIGHT side of the heart receives de-oxygenated blood (BLUE in colour) from the body and sends it to the lungs for gas exchange. Oxygenated blood (RED in colour) returns to the LEFT side of the heart, then gets pumped out to the whole body, through the aorta. Types of blood vessels: Arteries ○ Made of thick muscle layers and elastic connective tissue, to support the flow of high-pressure blood away from the heart. 2 purposes: Contractions prevent blood vessels from exploding due to high pressures from the heart Keeps blood from moving as it gets farther from the heart Veins ○ Made from thin muscle layers and elastic connective tissue, to support the flow of low-pressure blood back to the heart. ○ Due to the low pressure on the return trip to the heart, there are a series of one way valves to compensate. Capillaries ○ The walls of these blood vessels are only one cell thick, with pores between them, and so narrow that blood cells squeeze through in single file, ensuring that the maximum gas exchange can take place. Arteries, Veins and Capillaries Main exchange with outside: around alveoli of lungs inside villi of intestines Internal exchange: with every cell, tissue and organ of the body. The effects of poor valve control: Varicose veins → only gets worse over time Connection to the Digestive system ○ Nutrient absorption in the villi of the small intestines Respiratory system ○ Gas exchange in the alveoli of the lungs Blood pressure & Volume Cell specialization in the blood: Red Blood Cells (RBCs) ○ Small, round, biconcave discs which deliver oxygen and remove CO2 from all the cells in the body. ○ Get their red colour from the interaction between the oxygen they carry and the protein hemoglobin. White Blood Cells (WBCs) ○ When illness or disease are detected, WBCs will produce protective antibodies or surround and destroy bacteria as part of the immune system **(there is typically a ~700:1 ratio of RBC:WBC) The BLOOD Plasma ○ Is a clear liquid, of which nearly 90% is water, with dissolved nutrients (e.g. calcium, sodium, magnesium, etc.) ○ Acts as the transport mechanism for things like microbe-fighting antibodies, cellular wastes, and hormones. Platelets  ○ Irregularly-shaped, tiny & colourless bodies. ○ Their sticky surface lets them, along with other substances, form fibrous clots to stop any bleeding that occurs Diseases and disorders of the circulatory system Myocardial infarction → Heart attack ○ Fatty deposits “(plaque)” build up in the coronary arteries and become partially blocked. Condition called ATHEROSCLEROSIS (aka coronary artery disease) ○ If an area of plaque breaks open, a blood clot forms on the surface of the plaque. ○ Blood flow in the artery is blocked. ○ Some heart muscle cells die because they do not get the oxygen and nutrients they need and the heart stops pumping. Causes of heart attacks ○ Genetic factors, which include a family history of heart disease. ○ Lifestyle factors: Hypertension (high blood pressure) Lack of exercise Stress Smoking/vaping High alcohol consumption Poor diet (high salt and/or fat) Facts: Heart attacks are responsible for nearly 1 in every 5 deaths. In Canada, there are nearly 70,000 heart attacks per year. ○ That is one heart attack every 7 min Heart attacks kill ~16,000 Canadians per year ○ FYI: A severe or even mild case of COVID-19 can make you more likely to have heart failure or a heart attack. It's very rare for the virus that causes COVID-19 to infect your heart muscle. But the virus can cause problems throughout your body that lead to heart damage. Nervous system: Nervous system features: The nervous system coordinates all of the activities in your body, from breathing to digesting food, or sensing pain or feeling fear. Includes: Central Nervous System: ○ The brain ○ Spinal cord Peripheral Nervous System: ○ Nerves that connect sensory organs and all muscles to the central nervous system Neurons Nervous system tissues are made up of highly branched cells called neurons. Each neuron sends electrical signals down a long branch called an axon. ○ Axons can be so long that they must be nurtured and insulated by other cells called Schwann cells. Information travels between neurons using chemical signals called neurotransmitters. Nerve bundles: Nerves are bundles of axons from different neurons, surrounded by connective tissue and blood vessels. Nerve disorders: Parkinson's Disease loss of brain neurons that send neurotransmitters to muscles causes shaking and eventually leads to mental and muscular decline. Multiple Sclerosis (MS) The immune system attacks the insulation surrounding axons, disrupting electric signals. causes spasms and loss of muscle control. Alzheimer's Disease protein deposits build up inside brain neurons, causing their death. (amyloid plaques) causes memory loss and leads to total system failure. Osteoporosis: loss of bone tissue usually affects people of all ages, but most common in older women Musculoskeletal system Musculoskeletal system features: Main Functions of the musculoskeletal system: Structural support Protection of organs Body movement (when pulled by skeletal muscles ) Components: Four different connective tissues: Bones Ligaments Tendons Cartilage Bones A hard, dense tissue that contains:  Bone cells that produce ○ a surrounding matrix of minerals (mainly calcium and phosphorous) and fibrous collagen (protein). Bone marrow (stem cells) that produce blood cells (RBCs and WBCs). Blood vessels Joints Any point where two bones meet is a joint There are many types of joints in the body, allowing varying degrees of flexibility and body movement: ○ Hinge joint: knee/elbow ○ Ball and socket: hip and shoulder Tough, elastic connective tissues: Ligaments attach bones together across a joint. Tendons attach muscles to bones. Dense connective tissue: Cartilage cushions bone surfaces on both sides of each joint, and allows smooth movement. Skeletal muscles Muscles are made of bundles of long cells called muscle fibres. Muscles receive signals from the brain through the nerves. Criss-crossing fibres inside each muscle cell pull closer together, causing the muscle to contract. FYI: Three types of muscles: Smooth (e.g. diaphragm, digestive for peristalsis) Cardiac (e.g. heart) Skeletal (body) The nervous system links thoughts and actions by sending messages (as electrical impulses) from the brain to other body parts. Nerves and muscles work together in the neuromuscular system to make your body move as you want it to, and manage important functions such as breathing. How muscles make bones move: Muscles cannot push, (can only pull), they so they always work in pairs: ○ one contracts (pulls) ○ the other relaxes/extends (agonist/antagonist). Muscles anchored to one bone must cross a joint in order to pull on a second bone, resulting in movement. HOMEWORK: P101 1. The math functions of the musculoskeletal system include giving the body shape, movement, making blood cells, protection organs, and storing minerals  2. Tendon - serves to move the bone or structure Ligament - fibrous connective tissue that attaches bone to bone, serves to hold structures to keep them stable 3. Skeletal muscles are considered voluntary because they operate with a person’s conscious control 4. As we age, the ability to replenish bone is less than what is absorbed by the body. This reduces our bone mineral density P107 1. The nervous system is a complex network of nerves and neurons that carry signals or messages to and from the brain and spinal cord to different parts of the body 2. Visual input (seeing baseball coming). Processing in the brain, motor planning, signal transmissions to muscles, muscle activation and response 3. Brain controls drinking and feeding behaviour, controls muscles for eating and elimination, and the digestive system sends sensory information to the brain. 4. Sensory receptors process an environmental stimulus and convert it to electrical energy. Examples include photo receptors and thermoreceptors 5. MRI show skull structure and any brain bruising, bleeding or swelling. MRIs show the brain, spinal cord, and nerves more clearly than a regular x-ray or CT scan 6. Causes of hearing loss include: inner ear damage, temporal bone fracture or acoustic trauma. Immune system & Vaccination Disease: When microorganisms like bacteria or viruses enter the body, they release waste material These wastes can be toxic and damage other cells, causing the symptoms of the disease These harmful microorganisms called PATHOGENS ○ Pathogens causes disease → are NOT diseases First line of defense: Skin (epithelium has mucous membranes:) ○ Acts as a physical barrier to unwanted material Sweat and Tears ○ Chemicals in these fluids act to kill bacteria Stomach Acid ○ Gastric juices kill bacteria in the food we swallow Beneficial (“Good”) Bacteria ○ occupy the “real-estate” of exposed surfaces on your body Second line of defense: White blood cells: There are several types of white blood cells, each with their own function. The two main ones are: WBCs that ingest pathogens and destroy them with their lysosomes.  WBCs that produce special protein molecules called antibodies. WBCs That Ingest Pathogens 1. Chemical signals from infected body tissues are received by WBCs in capillaries 2. WBCs squeeze through the pores between capillary cells and crawl towards the pathogens 3. WBCs engulf and destroy the pathogens WBCs That Produce Antibodies Antibodies are secreted proteins that attach to specific molecules from invading pathogens. The attached antibodies then stick to each other, causing the pathogens to clump together. Antibodies Antibodies have three beneficial effects: 1. Prevents further spread/infection by the pathogen (particularly for viruses) 2. Covers the toxins, preventing them from causing harmful reactions 3. Flags pathogens and toxins for destruction by ingestion by the first type of WBC Acquired immunity Why would “antibody producing WBCs” continue to replicate for years after an infection? In order to keep a “memory” of the pathogen! Just in case you come in contact with it again! ** In most cases, you can only get sick ONCE from any one pathogen All organisms (including non-living viruses) have the ability/possibility of mutating and evolving, which may lead to your antibodies no longer recognizing them – no longer able to destroy them. ○ so every cold you get is from a NEW (mutated) VERSION of an existing virus and should be updated annually since their genetic code changes more often. Vaccination People can be immunized against a pathogen through vaccination. Vaccination involves injecting a small amount of weakened or harmless version of a pathogen, allowing you to acquire immunity without getting the disease. Some people, however, may suffer a mild reaction. Sometimes vaccine booster shots are required because the immune response’s “memory” weakens over time. To be, or not to be… Vaccinated? When fewer people are vaccinated, the number of cases of the disease increases. ○ Individual decisions can have a major impact on a whole society! The chance of falling seriously ill or dying from the disease is far greater than the chance of experiencing any serious side-effect from the vaccine. Using a vaccine is cheaper than treating a very ill person. Herd immunity: the shield of protection that persons with immunity to an infection provide to those around them who are not protected against it. Vaccination myths: 1. causes chronic diseases (Crohn’s, MS, autism, etc.) 2. weaken the immune system 3. contain toxic substances 4. are not necessary because the disease is gone 5. “Vaccines are not safe” 6. “Vaccines don’t work” Endocrine system The endocrine system allows organs to coordinate their functions with each other It uses chemical messages called hormones that are: Longer-lasting Slower moving (relatively) Targeted to many organ systems Only cells with the correct receptors on their membranes are able to respond to a specific hormone The endocrine system is composed of a series of gland tissues that secrete hormones into the bloodstream. Endocrine organs Pituitary gland Produces hormones that control the function of other organs in the body (eg LH, FSH, GH, etc. ~7 hormones) Aids in the proper growth and development of body tissue Pancreas Secretes insulin to ensure sugar regulation in the body Gonads (testes and ovaries) Secretes sex hormones (testosterone and estrogen) responsible for reproductive abilities of the body Adrenal Glands Secretes a series of hormones to control the body’s response to stress Estrogen, progesterone, adrenaline, dopamine, etc. “Fight or flight” response by releasing adrenaline (aka epinephrine - Epipens narrow your blood vessels and open up bronchioles during anaphylaxis) Endocrine disorders Diabetes Type 1 (childhood): The body loses the ability to produce insulin Insulin is a hormone produced by the pancreas Used for metabolism of glucose to release the energy for use by our cells Type 2 (adult onset)” The body produces less insulin than normal and the body loses the ability to make efficient use of the insulin that is produced ○ Results in high levels of sugar in the blood instead of the body cells ○ Causes high blood pressure, heart disease, vision impairment, slow healing, tiredness and amputation Growth disorder (eg: Gigantism/Dwarfism): Children born with a poorly functioning pituitary or hypothalamus or adults whose glands become damaged by tumours, infection, radiation Connecting /linking organ systems 1. MOUTH Food and oxygen are ingested 2. SMALL INTESTINE Nutrients are absorbed by the digestive system 3. LIVER Destroys toxins, stores and releases sugar (glycogen) into blood, as needed 4. HEART Deoxygenated blood leaves the heart headed for the lungs 5. LUNGS Gases are exchanged CO2 diffuses out of the blood (to be exhaled) O2 diffuses into the blood 6. HEART Oxygenated blood leaves the heart for the body (organs, tissues, muscles, etc) 7. CAPILLARIES Gases and nutrients are exchanged between the blood and body tissues (brain) ○ nutrients and O2 transferred into tissues; ○ wastes and CO2 transferred into blood 8. KIDNEYS Filters excess fluids and cellular waste from the blood, creating urine (stored in the bladder) for excretion. Plants Plants have serveral “lifestles” differences compared to animals: They build their organic compounds using carbon from CO2 in the air and hydrogen from water (in the soil) Plants get energy to do this by capturing sunlight (photosynthesis) All additional elements and nutrients they need are absorbed from the soil Needs Plants need to gain energy fromm sun and water/nutrients from the soil ○ This means that the plant needs to have as much surface area as possible available fro these transfers to take place Roots, stems and leaves are designed to mmacimize surface area Plants also maimmize surface area through  1. Layed branches (little stems) around a central stem 2. Branching roots (underground) which end with very fine root hairs (entensions of each cell membrane … like the microvilli in intestines) 3. Broad, flat leaves to maximize photosynthesis How could someone inane (inflate lungs) without muscles? The branches and leaves are the lungs ○ Similar to bronchioles and alveoli Differences between plants and animals Without having to eat, plants have far fewer complex tasks to perform ○ As a results, plants lack many of the tissues/organs present ina animals, such as: Muscles: Plants have no need to move around to collect/gather food (bending doesn’t count) Bones: Plants have no need to support soft, flexible muscles (that are found in animals). They do have cell walls and large central vacules Central nervous syste: Plants have no need for a brain to communicate/control muscles (“fight or flight” response evading prey, but they do have hormones like aucin to grow towards light) Gas exchange Leaf labels The bottom of each leaf is composed of a very spongy layer, with lots of air spaces and many mouth-like openings called stomata (plural) that are controlled by the opening and closing of guard cells, which surround the stomata. Gases can easily diffuse in and out of plant leaves, through the epidermis, and come in direct contact with the cells of the plant. As such, there is no need for red blood cells to transport them as in a circulator system  Only the mesophyll cells in the mddle of the leaf contain chloroplats and do photosynthesis Transport Without a heart muscles (central pump), the plant uses water to carry substances fromm areas of high concentration to areas of low concentration (OSMOSIS - explained in gr 11) Plants bundle their transport tissues into “vascular bundles” → veins ○ Phloem Transport sugars (made by chloroplasts in the leaves) from the leaves t the roots ○ Xylem Transports water and nutrients from the roots to the leave Plant stem cells Lateral meristem ○ Located in the roots and under the protective bark in the stems of woody plants ○ These enable the plant to grow wider/thicker ○ Each year’s growth of new vascular cambium forms a visible ring of cells; identified as “tree rings” in the cross section of a tree trunk Apical meristem ○ Located at the tips of roots and shoots ○ These enable the plant to grow longer and to form new branches and form axillary buds on roots and main stem.