Circulatory System and Excretory System - PDF

Science- online notebook Circulatory System The circulatory system, transport/distribuite, moves blood throughout your body. Bring oxygen and nutrients to your organs, muscles and tissues. Remove waste products like carbon dioxide and your organs’ chemical byproducts. Blood Is made up of two elem...

Science- online notebook Circulatory System The circulatory system, transport/distribuite, moves blood throughout your body. Bring oxygen and nutrients to your organs, muscles and tissues. Remove waste products like carbon dioxide and your organs’ chemical byproducts. Blood Is made up of two elements: ​ Blood Plasma 55%- extracellular matrix contains several nutrients but no oxygen. ​ Blood Cells 45%- These are cells that will help you take in all the oxygen needed. Thanks to the hemoglobin they will be able to absorb a large amount of this oxygen. Thanks to this big absorption, it will be able to transport the oxygen all around our body. -​ Red blood cells: also called ERYTHROCYTES, no nucleus, transport oxygen through the blood, contain hemoglobin, an iron-rich protein that gives the blood its red colour. -​ White blood cells: also called LEUKOCYTES, have nucleus, are part of the body’s response to infections and other foreign substances, and they have memory. -​ Platelets: also called THROMBOCYTES, they cover up all the blood, participate in blood clotting, when a blood vessel is broken platelets are attached to the site of the injury and they create a clot to stop the bleeding. Blood cells are produced in bone marrow, a tissue found inside many bones. Blood Vessels Are tubes, which blood flows through. The blood vessels form a network through which the blood flows in a closed circuit and always in the same direction. There are three main types; each one performs a different function in the human body. ​ Arteries: transports the blood from the heart into all the different organs. It contains a high blood pressure of blood as it has to arrive. ​ Capillaries: is the one that is going to carry out the blood into the specific parts of the organ. It is going to be split up by the arteries. ​ Veins: are specialised in carrying the blood into the heart so that they are filled up with oxygen. Heart Parts Veins and arteries: are the vessels that connect the heart with the organs and tissues of the body. Blood flows out of the heart through the arteries and flows back to the heart through the veins. Atria: are the heart’s two upper chambers. Each atrium has thin walls and is connected to a large vein. Valves: separate the chambers and ensure that blood flows in the correct direction, opening or closing as the heart contracts. Ventricles: are the heart’s lower chambers. When the muscular walls of the ventricle contract, blood is pumped out. They are connected to large arteries. The Circulatory system process To circulate through the body, blood must pass through the heart twice and complete two circuits:  ​ The first circuit is called pulmonary circulation. Blood rich in Co2 and poor in O2 flows from the heart to the pulmonary alveoli. Gas exchange takes place there, and the oxygen-rich blood flows back to the heart. ​ In the second circuit, called systemic circulation, oxygen-rich blood flows from the heart to all organs and tissues throughout the body. Once there, the cells in the body absorb O2 and release Co2, the product of cellular respiration, into the blood. The blood flows back to the heart carrying the waste carbon dioxide. Excretory System The urinary system is a system by which our blood gets filtered. It is going to make sure that our blood is purely filtered, producing a substance called urine by which this urine is going to be stored inside our bladder. Having our blood with the ability of removing wastes such as urea, can help us to prevent our body's from issues or problems. Blood filtering Unfiltered blood (blood that contains salts, urea, water and glucose) enters the kidneys through the renal artery, where it is filtered and the waste products form primary urine, while the filtered blood goes back to the organism via the renal vein. 1)​ Nephrons Inside the kidneys there are units called nephrons which is where the blood filtration occurs. Unfiltered blood enters through the renal artery into the glomerulus which is inside the capsule, and here is where nutrients, water, urea and salts get filtered and form primary urine. Primary urine exits the capsule and enters the tubule while the filtered blood passes through the capillaries which then merge into the renal vein. However, there is a final filtration that occurs when the renal vein and tubule come in close contact. The nutrients in the primary urine exit the tubule and enter the blood once again, so then a nutrient-dense blood goes to be distributed to the body. 1)​ Ureters Tube-like structures that direct urine to the bladder. 2)​ Bladder Hollow organ that stores urine until it’s full and you have the need to go to the bathroom. 3)​ Urethra The tube by which urine leaves the body. Excretory system parts Interactions with the environment We humans interact with our surroundings and the living organisms around us. These two elements make up our environment. By interacting with their external and internal environment, humans detect changes and respond to them accordingly to be able to survive and reproduce. Interaction with the environment occurs in three different stages: 1.​ A stimulus is detected by structures or organs called receptors. 2.​ The stimulus is relayed and interpreted by coordination systems, which produce a response. 3.​ The organism responds by means of organs or structures called effectors. Receptors Receptors are the structures human beings use to detect stimuli. Stimuli: is anything that causes a response or reaction in an organism. It can be something external, like light or sound, or internal, like hunger or pain. Receptors can be classified by the location of the stimuli that they detect: ​ Interoceptors: collect information about the human body’s internal conditions. These receptors, located in the internal environment, mostly respond to chemical stimuli. ​ Exteroceptors: provide information from the body’s outside environment and are therefore located on the surface of the body. Sense organs are exteroceptors. ​ Proprioceptors: inform about the relative position and condition of each of the body's muscles. Proprioceptors provide information concerning body position and body motion, as well as on the relative position of body parts. These receptors are located in the inner ear’s vestibule and the locomotive system (muscles, tendons, and articulations), respectively. As with most animals, exteroceptors in humans are organized into sense organs, structures specialized in detecting stimuli from outside the body and carrying the information to the nervous system. Coordination We humans need all our cells, tissues, and organs to be properly organized and coordinated. Only in this way can we respond to changes in the outside environment and inside us. The role of coordinating systems is to: 1.​ Receive the information collected by the receptors. 2.​ Interpret the information received and produce an appropriate response. 3.​ Activate the organs required to perform this response. There are two major types of coordinating systems: ​ The nervous system:is made up of nerves, the brain, and the spinal cord. It processes the information sent by the receptors—both internal and external—and generates fast, short-lived responses. The information is rapidly transmitted through nerve impulses. ​ The endocrine system: is formed of endocrine glands which, when stimulated, secrete hormones into the blood stream. Blood carries these chemical signals to target tissues and organs, where they trigger slower, long-lasting responses. Responses Are the changes that the human body experiences when the coordinating systems have detected and interpreted stimuli. Effectors: are organs, tissues, or cells that carry out responses. These responses are carried out by muscle or glands, and are therefore classified as: ​ Motor responses: involve movement, and muscles are the effectors of these movements, either in the locomotor system or the viscera. ​ Secretory responses: involve the production and secretion of substances by endocrine or exocrine glands. INTERNAL → The inside of our body EXTERNAL → The environment around us Surrounding + living organisms = Environment Interaction with the environment: 1)​ Stimuli A stimulus is detected by the sense organs. For instance, you burn your hand. EYE Organ that we use to see light. Has photoreceptors which are a type of cell that transform light into nerve impulses. ​ 1)Cornea A lens that helps focus the light rays that come from light sources. Is a transparent membrane with a liquid inside that protects the pupil and iris. 2) Iris Regulates how much light enters the pupil by adjusting its size, thanks to muscle fibers it has. Is a coloured circular membrane. 3) Pupil An opening by which light passes. In dim light, the iris contracts and the pupil expands. In bright light, the iris expands and the pupil contracts. 4) Crystalline lens Enables light to converge in the retina so that images can be produced. It can do this because of a process called accommodation that takes place thanks to its shape. 5) Retina The inner surface of the eye. Acts like a screen for the light rays to be projected. It is a photosensitive tissue that contains 2 types of cells. Rods and cones. Rods detect light intensity while cones detect colour. These two turn light waves into nervous stimuli. 6) Optical nerve Nervous impulse is transmitted to the brain to be interpreted. NOSE Organ that allows us to smell the particles in the air thanks to the chemoreceptors in the olfactory mucus. → Olfactory mucus = has chemoreceptors which turn stimuli into electrical impulses → Olfactory bulb = collects the electrical impulses and directs them to the olfactory nerve → Olfactory nerve = transmits electrical impulses of odors to the brain where they are integrated and interpreted. ​ EAR An organ that detects vibrations thanks to the mechanoreceptors cells they have. 1) Outer ear → Pinna = The part of the ear we can see and touch. It captures sound waves and sends them through the ear canal. →Ear canal = A short passage from the pinna to the eardrum where sound waves travel. 2) Middle ear → Eardrum = A membrane that vibrates when the sound waves arrive. →Ossicles = Three little bones that vibrate along with the eardrum. They are called malleus, incus and stapes. → Eustachian tube = A little passage from the middle ear to the nose, to alleviate the pressure in the eardrum. 3) Inner ear → Vestibular system = Organ of balance. Contains proprioceptors. →Cochlea = Filled with a liquid and cilia. Receives sound vibrations and its thousand cells turn the stimuli into nerve impulses which are then sent to the brain. →Auditory nerve = Sends the nervous impulse to the brain to be interpreted. ​ TONGUE Allows us to taste substances found in liquids in the oral cavity. It has chemoreceptors in the surface of the tongue, (taste buds). → Taste buds = tiny bumps that cover the surface of the tongue. They have nerve endings and taste receptors. 1)​ Taste receptors = Chemoreceptors that detect substances in the saliva and oral cavity. They turn it into electrical impulses. 2)​ Nerve endings → They receive the electrical impulse from the taste receptors they are connected to, and send the information to  the brain. ​ SKIN Physical touch detects stimuli through changes in the environment. Touch receptors located in the skin: 1)​ Mechanoreceptors = Detect changes in pressure → Meissner’s corpuscles → They feel light pressure changes, like being touched by a feather → Pacinian corpuscles → They feel hard pressure changes, like being struck 2)​ Thermoreceptors = Changes in temperature → Krause corpuscles = They feel decrease in temperature → Ruffini corpuscles = They feel increase in temperature 3)​ Nociceptors = Pain → Free nerve endings 2)​ Stimuli is interpreted The burn in your hand is interpreted by the coordination systems, nervous or endocrine. And thus, a response is sent.  3)​ Response done by the effectors Organs, cells and tissues that carry out a response. -​ Interoceptors Detects changes in the body. Mostly chemical stimuli. -​ Exteroceptors Detects changes in the surroundings. Mostly physical stimuli. Locomotor system carries out motor responses. -​ Propioceptors Detects the balance of the body. Is in charge of being aware of changes in position. 2 types of response 1)​ Motor Movement, like blinking or our heartbeats. 2)​ Secretory Creating gastric juices or hormones in our body. NERVOUS SYSTEM Reacts to stimuli quickly and sends short-lasting responses. Information is sent to this CNS (central nervous system) by sensory nerves. Inside the brain, info is transmitted via nervous impulses, and lastly from the brain to the receptors, it travels in motor nerves. NS Divided into: - ​ Central nervous system 1)​ Brain (100 000 million neurons) → Cerebellum- Muscle control including balance → Cerebrum- Speaking, critical thinking, movement, temperature, senses, problem-solving, emotions and learning. → Brainstem- Breathing, heart rate, blood pressure and sleep 2)​ Spinal cord- Send motor commands, send sensory info from the body to the brain, coordinate reflexes. -​ Peripheral nervous system- Nerves 1)​ Autonomic = Involuntary, breathing, heart rate, bowel movements. 2)​ Somatic = Voluntary and reflex movements. The Nerves impulses Information travels at incredibly high speeds through the nervous system as an electrical signal called a nerve impulse. Nerve impulses travel at a range of speeds between 3 m/s and 120 m/s. Nerve impulses are transmitted between neurons, the main nerve cells. 1.​ Nerve impulses travel from the receptors to the central nervous system by way of sensory nerves. 2.​ Once in the nervous central system, nerve impulses are transmitted to the areas where a response, which is also a nerve impulse, is produced. 3.​ This new nerve impulse travels to the effectors by way of motor nerves. In most of its pathways, motor nerves and sensory nerves are grouped into mixed nerves. Neurons Neurons are cells specialized in producing and transmitting electrical nerve impulses. There are three types of neurons: ​ Sensory neurons: nerve cells that detect external stimuli. ​ Relay neurons: nerve cells linked to other neurons that form networks within the central nervous system. They take part in producing responses. ​ Motor neurons: nerve cells that send responses from the central nervous system to the effectors. Neurons have a cell body—the soma—that contains the nucleus. A large number of extensions called axons and dendrites jut out from the soma and connect with other neurons or cells through gap junctions called synapses. ⬇ The nervous system also includes glial cells, which ensure that neurons stay healthy. Structure: Cell body (nucleus) = Soma Extensions = Dendrites and axons Connection points between neurons: Synapse x ENDOCRINE SYSTEM Made up of glands and organs. In charge of internal body stimuli. Takes a bit longer to react, but sends long-lasting responses. Secretes hormones into the bloodstream which then go on to the target organs and tissues to control and coordinate the body’s metabolism, energy level, reproduction, growth and development. As well, as a response to injury, stress and mood. Each hormone has target cells which they release a response from. Hypothalamus = Where the endocrine and the nervous system come together. Produces hormones to regulate other glands (pituitary). Pituitary gland = The main gland in the system. In charge of sexual maturity, water balance, growth and blood pressure. Pineal gland = Secretes melatonin Thyroid = Metabolism and growth. Regulating protein synthesis and sensitivity in cells. Parathyroids = Regulates calcium levels in blood, bones, kidney and intestinal absorption of the nutrient. Adrenal glands = Secretes corticosteroids and adrenaline. Pancreas = Insulin and glucagon secretion. Ovaries = Sex hormones, estrogen and progestogen Testes = Testosterone Behaviour A set of responses to stimuli that humans have. Incredibly varied, by ultimately divided into 2:  1)​ Innate behaviour These are the abilities we were born knowing. How to eat, drink water, breathe, → Reflexes Are automatic and almost involuntary responses to stimuli. Usually coordinated by the spinal cord. →Instincts Automatic, but long-lasting response to certain stimuli. 2)​ Learned behaviour These ones depend on our environment. For example, to play an instrument.