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Rep Ex Im Di Ci S Complete the following words: Human Body Systems Res M N En In Biggest: Smallest: Organization of the Human Body Organ Systems ? Organism ? Tissues ? Organs ? Cells ? HomeostasisHomeostasis is how the body keeps conditions inside itself the same. Scientists describe it as the maintenance of a constant internal environment.
Some examples of things that our body's keep the same are:
Keeping these the same is not always easy or simple when the outside environment is changing constantly. But it is important so that all our cells function properly.
Strenuous exercise, or living in a hot or cold environment, affect our oxygen levels, body temperature, water and salts balance. First: Second: Third: Result: HOW does our body keep the levels balanced??? e.g. e.g. e.g. - we need effectors to produce a response that ensures our body's levels will return to normal ? - we need receptors (nerves) to detect when variables are changing! ? Our body temperature is mostly unchanging and safe :))) ? - we need a processing centre to receive this information and coordinate our response (reaction). ? In an incubator: The computer switches the heater on or off! ? In an incubator: A computer or processing centre monitors and processes the data from the sensors and decides what to do next! ? An incubator needs thermal sensors to monitor the temperature... ? Environment stimulus: Blood sugar! high blood sugar low blood sugar Homeostasis ? Result: receptors in the pancreas detect too little glucose ? receptors in the pancreas detect too much glucose in the blood! ? What happens? is the function of keeping the body stable in the internal environment. Blood sugar (glucose) levels return to normal! ? Body Reaction: produce more glucagon & less insulin ? produce insulin ? How it helps: all cells absorb more glucose from the blood? liver excretes more glucose into the blood ? Environment stimulus: Temperature! Homeostasis ? cold hot Result: is the function of keeping the body stable in the external environment. skin hairs stand up Our body's Reaction: Body temperature returns to normal ( ≈ 37oC ) ? sweating ? shivering ? keeps a layer of warm air next to the skin - acts as an insulator? How it helps: produces heat ? cools off ? BLOOD FLOW MUSCLES HAIRS SWEAT Blood flow in capillaries decreases. Heat is kept in the body's core. ? Hair muscles pull hairs on end. Erect hairs trap air. ? Shivering - muscles contract and release rapidly. ? No sweating. TOO COLD ? ENVIRONMENT STIMULUS Blood flow in capillaries increases (so more heat can be released at the skin surface). ? Sweat secreted by sweat glands. Cools skin by evaporation. ? Hair muscles relax. Hairs lie flat so heat can escape. ? TOO HOT ? No shivering Environment stimulus: Water levels in our blood! too much water too little water Homeostasis ? Result: hypothalmus detects too little water in our blood! ? hypothalmus detects too much water in our blood! ? What happens? is the function of keeping the body stable in the internal environment. Blood water levels return to normal ? Body Reaction: pituitary gland releases less ADH. ? pituitary gland releases more ADH. ? kidneys extract water from our blood and send it to our bladder (urine is less yellow!!). ? kidneys keep water and send it back into blood circulation (urine is more yellow!!). ? How it helps: connective ? epithelial ? muscular ? nervous ? 4 Types of Tissue directs & controls body contracts & shortens to move the body provides support covers inside & outside surfaces of the body |