Unit 4 - intro to homeostatis

Question 1

what is homeostasis

Answer 1

ability of an organism to maintain a stable internal environment, depsite changes to its interlan or external environment
homosis = similar
stasis = standig still

Question 2

Internal Environment

Answer 2

the IE refers to the extercellular fluid which condsists of IF that fills the space between out cells and tissues and plasma or fluid portion of our blood

Question 3

Homeostasis focuses in on…

Answer 3

the fluid outside the cell which act as a medium for delivering energy transporting chemical and eliminating waste

Question 4

Organ systems involved in Homeostasis

Answer 4

1) nervous =
brain/ spinal cord
2) endocrine =
thyroid/adrenal gland
3) muscular =
skeletal / cardiac
4) integumentary =
skin / sweet / nails / hair
5) excretory =
kidney / bladder
6) reproductive =
testies / overies

Question 5

internal environment

Answer 5

when cells function properly in the tissues and organ systems the whole organ can thrive

Question 6

Temp, volume, chemical composition…

Answer 6

of internal environment can change quickly

Question 7

rigorous physical activity, extreme conditions or infections

Answer 7

can tip the balance in the extracellular fluid

Question 8

dramatic changes ( often -)

Answer 8

effecting cellular functions, so the body uses many systems to maintain and regulate its internal conditions

Question 9

Normal body ranges (7)

Answer 9

body temp = 37c
bp = 120/80
blood pH = 7.3-7.5
o2 and co2 conc.
water balance
blood glucose = 0.1%
calcium levels = 8.5-10.5

Question 10

Homeostasis and Feedback mechansms

Answer 10

Homeostasis is monitored through constant monitoring and feedback of body conditions. If conditions are outside of the optimal functioning range, the mechanisms take corrective action to bring the body back into balance.

Question 11

How does homeostasis work = feedback pathways

Answer 11

• organs and structures communicate with each other in response to changes in the body
• Keeps levels of certain processes within a normal range

Question 12

3 components

Answer 12

sensor
integrator
effector

Question 13

Sensor; receptors

Answer 13

tissues or organs that detect any change—or stimuli
Gathers and transmits to Integrator

Question 14

Integrator; brain

Answer 14

acts as a processor or control centre. compares the environmental conditions with the optimal functioning condition know as set point

Question 15

environment outside of set point =

Answer 15

the integrator activates the effector

Question 16

Effector; muscle and glands etc

Answer 16

returns that measured conditions to the desired set point know as the response

Question 17

Positives vs. Negative Feedback

Answer 17

Negative Feedback: mechanism in homeostasis whereby the output reverses the variable bringing it back to a normal state of balance.
Positive Feedback: mechanism in homeostasis whereby the output strengthens and increases the change in the variable.

Question 18

Negative Feedback

Answer 18

process by which a mechanism is activated to restore condionts to there orignal state
ie. small changes dont bc to big
- cellular materials
- energy

Question 19

Negative Feedback ex

Answer 19

Thermostat in a house

Question 20

top feedback loop

Answer 20

if room gets hotter then set point thermostat will detect change and turn on air conditioner to cool room and return to set point

Question 21

bottom feedback loop

Answer 21

room gets colder then the set point the thermostat will detect the change and turn on the furnace in order to warm the room and return to the set point

Question 22

Thermoregulation; core temp

Answer 22

• humans normal temp between 35 to 38.6c
  above (hyperthermia)=
  infection
  below (hypothermia)=
  cell death

Question 23

Heat Stress; sensor

Answer 23

thermoreceptors of the peripheral nervous system detact an increase in body temp. send message via seneroy neurons to brain

Question 24

Heat Stress; integrator

Answer 24

Hypothalamus (CNA) signlas via motor neruons to sweat glands

Question 25

Heat Stress; Effector

Answer 25

sweat glands initiate sweating evaporating sweat off the skin = cooling

blood vesicles in the skin dilate allowing blood to flow to the skin and heat from blood is lost to the skin so blood can return to core temp

Question 26

Result of heat stress

Answer 26

body temp returns to normal hypothalamus turns of cooling system

Question 27

cooling glove

Answer 27

heat extractor increases heat loss and allows the body to perform a higher level in sever conditions

Question 28

Cold Stress; Sensor

Answer 28

thermoreceptors message the hypothalamus using sensory neurons

Question 29

Cold Stress; Integrator

Answer 29

hypothalamus send a message via motor neurons

Question 30

Cold Stress; Effector

Answer 30

arterioles of the skin constrict therefore limiting blood flow and reducing heat loss from the skin

Question 31

cold stress smooth muscles

Answer 31

that surrond the hair follicles in your skin contract causing hair to stand trapping warm air

Question 32

cold stress skeletal muscles

Answer 32

contract causing shivering and increasin metabolism to make heat

Question 33

result of cold stress

Answer 33

body temp increase and hypothalamus turns off heating system

Question 34

blood sugar levels spike

Answer 34

beta cells in the pancrease will release insulin. Insulin is detected by cells and they begin to take up glucose and storing it as glycogen

Question 35

blood sugar levels drop

Answer 35

alpha cells in plancreas release glucagon which signals cells to release glucose by breaking glycogen

Question 36

Insulin

Answer 36

produced by b cells of the pancres
released into circ system when blood glucos is high
facilitates tranposrt of glucose into target cells

Question 37

glucagon

Answer 37

make by a-cells of pancrease
released into circ system when blood glucose is low
signals the liver to break down glycogen into simple glucose

Question 38

positive feedback

Answer 38

babies being born where oxytocin is released and strengthens the response of contractions + in milk glands oxytocin released during breastfeeding to increase the mothers milk supply.