Homeostasis Practical Report

ABSTRACT

The main aim of the experiment was to test to see if the human body can maintain a relatively stable internal temperature (maintain homeostasis) whilst being exposed to extreme external temperatures for 20 minutes. This was achieved by subjecting a total of 9 humans (14-15 years of age) into 3 allocated rooms ( a hot room (23'C), a cold room (12'C), and a control room (19'C)) All the subjects feet were in a bucket of water of different temperature; hot room (40'C water), cold room ( cold water), control room (lukewarm water)  and  the subjects were given a hot, cold, or lukewarm drink and water bottle/ ice pack, in accordance to the overall temperature of the room. Every 5 minutes the subjects were tested for their heart rate and body temperature along and observations were documented. The experiment concluded the following averages of change for each room in terms of temperature (T) and heart rate (HR) tested every 5 minutes (m). Cold room; 0m  HR(102),  T(35.3), HR(94),  T(33.9), 10m  HR(92),  T(34.9), 15m  HR(92),  T(34.8), 20m  HR(94),  T(35.3).  Hot room; 0m  HR(76),  T(35.7), 5m  HR(108),  T(37.5), 10m  HR(100),  T(36.8), 15m  HR(100),  T(37.1), 20m  HR(100),  T(36.6). Moderate room; 0m  HR(113),  T(36),  5m  HR(96),  T(35.6), 10m  HR(87),  T(35.9), 15m  HR(86),  T(36.6), 20m  HR(75),  T(36.4).

INTRODUCTION

External temperatures are continuously fluctuating significantly however it is vital for organisms such as humans to keep a relatively constant internal environment within its acceptable limits so that bodily functions can occur efficiently and effectively in order to maintain life. Humans internal body temperature in terms of normal ranges between 36.1'C and 37.2'C. This internal body temperature is constantly being regulated by the hypothalamus. The hypothalamus is the control center in the brain which is responsible for maintaining a stable internal body temperature (maintaining homeostasis). The is is achieved by the body's receptors ( specialised cells that detect change)  picking up change in temperature within the environment and sending a signal along nerve cells (neurones) to the central nervous system (comprised of the brain and spinal chord) and coordinates a response by comparing the detected change in temperature with the setpoint (the temperature  level which the body attempts to maintain its temperature). This response is carried out via the effectors to counteract the original change detected. This counteraction of the original change detected is referred to as negative feedback.

AIM

To investigate if the response of homeostasis in the human body can maintain a relatively stable internal temperature whilst being exposed to extreme external temperatures.

HYPOTHESIS

When the human body is exposed to the extreme environment their body will be a subject of change in terms of their heart rate and body temperature. The subject's body temperature in the cold room will decrease by 1'C at 5 minutes then increase by .8'C at 10 minutes, at 15 minutes it will decrease by 1'C and at 20 minutes it will increase by .6. And the subjects heart rate in the cold room will decrease by 10% at each 5-minute interval. The subject's body temperature in the hot room will increase by 1'C at 5 minutes then decrease by .8'C at 10 minutes, at 15 minutes it will increase by 1'C and at 20 minutes it will decrease by .6. And the subjects heart rate in the cold room will increase by 10% at 5 minutes then continue to increase at a rate of 5% at every 5-minute interval. The subject's body temperature in the moderate room will decrease by .3'C at 5 minutes then increase by .3'C at 10 minutes, at 15 minutes it will decrease by .4'C and at 20 minutes it will decrease by .4. And the subjects heart rate in the moderate room will decrease by 10% at 5 minutes then continue to decrease at a rate of 5% at every 5-minute interval.

MATERIALS

⦁    9 thermometers

⦁    3 glass thermometers

⦁    9 buckets

⦁    3 ice packs

⦁    3 hot water bottles

⦁    9 towels

⦁    9 cups ( 3 of which must be mugs)

⦁    Time recording/measuring device

⦁    Camera device

⦁    18 Alcohol Swabs

⦁    Kettle

⦁    prepared hot chocolate

⦁    ice 5kg

⦁    heater

⦁    3 rooms

METHOD

i.    Three rooms were allocated; a hot room, cold room, and moderate room. The hot and moderate rooms where ensured access to a heater and the cold room was naturally cold.

ii.    9 human subjects were selected (5 of which were girls and 4 of which were boys).  

iii.    The heaters were turned on in the hot room and the moderate room. The heater in the hot room was programmed to maximum heat and the heater in the moderate room was turned to 20'C.

iv.    The rooms were then each set up with 3 chairs, cups, 3 buckets, 3 thermometers, 3 towels, a glass thermometer, a camera and a time measuring device. The buckets were roughly half filled with water and were placed on towels, each at the base of a chair. The water in the buckets temperature varied in accordance with the room; hot room's buckets (40'C), cold room's buckets full of ice and moderate rooms bucket full of lukewarm water. The cups in the cold room where filled with iced water and the cups in the moderate room were filled with lukewarm water.

v.    3 hot water bottles were prepared and 3 ice packs were taken out of the freezer.

vi.    3 serves of hot chocolate were prepared, whilst the 9 subjects were gathered and 3 people were allocated to different rooms evenly (3 people in each room)

vii.    With at least one scientist was assigned to each room, the subjects were photographed and their body temperatures were measured with a sterile thermometer (cleaned prior to alcohol swabs) along with their heart rate.

viii.    The subjects allocated to the hot room allowed their feet to warm up before submerging them in hot water as a safety procedure

ix.    A timer was set for 20 minutes and the subjects were then seated and their bare feet were placed in the allocated buckets (one bucket per person). The subjects in the cold room were given ice packs to wrap around their wrists and the people in the hot room were issued hot water bottles. The room temperature was recorded

x.    The hot, hot chocolate was transferred into allocated cups in the hot room and was issued to the subjects along with all the other drinks in different rooms.

xi.    Every five minutes the subjects pulse and body temperature was measured and documented along with observations such as behaviors, shivering/sweating, and facial complexion.