homeostasis

Question 1

what is homeostasis?

Answer 1

a basic characteristic of living things, it is the steady state of physiological conditions in the body

Question 2

what are the basic mechanisms of homeostasis?

Answer 2

feedback regulation: stimulus -> response -> increase or reduce stimulus -> stimulus –>response -> increase or reduce stimulus…

Question 3

what are the two types of feedback regulation?

Answer 3

negative feedback, which is where the response to stimulus REDUCES the stimulus (more common) and positive feedback which is when the response to stimulus AMPS the stimulus

Question 4

what is osmoregulation?

Answer 4

the process by which organisms regulate the concentration of water & solutes in their bodies to maintain internal stability (homeostasis) in relation to the surrounding environment

Question 5

what is a paramecium and how does its osmoregulation work?

Answer 5

a unicellular protist that is generally aquatic. in a hypotonic environment (more solute in cell than outside) the water moves inward via osmosis. the contractile vacuole is an organelle that is used to pump water out to maintain water balance and prevent lysis.

Question 6

what is a jellyfish phylogeny and how does its osmoregulation work?

Answer 6

jellyfish belong to the phylum Cnidaria, which includes animals with simple body plans. They have a diploblastic development, meaning their bodies are composed of two adult tissue layers: the epidermis (outer layer) and the gastrodermis (inner layer). Jellyfish do not have a dedicated circulatory system like more complex animals. Instead, all internal fluids, including water, nutrients, and waste products, move through the body via diffusion.

Question 7

how does homeostasis work for all organisms?

Answer 7

all organisms must regulate internal enviornment and exchange with outside enviornment. the mechanisms depend on enviornment and type of organism

Question 8

how does osmoregulation work for humans?

Answer 8

humans have evolved from marine environments and must maintain conditions similar to the marine environment internally, including gasses, pH, etc. they have various adaptions for terrestrial life such as:
- the amniotic sac for reproduction/development
- scales/skin for water balance
- excretory system for waste removal

Question 9

what are homeostasis constraints in animals?

Answer 9

constraints on animals body size/shape include limitations from physical laws like strength, diffusion, movement, and heat exchange.

Question 10

what is an example of constraints on animals?

Answer 10

the shape of swimming animals is contrainued by the properties of water, which is denser and more viscous (thick) than air. these constraints result in animals evolving smooth and streamlined shapes to reduce drag and move more efficiently through water. there are diverse organisms in the same environment that can exhibit similar adaptions (convergent evolution)

Question 11

what is the significance of animals not being closed systems?

Answer 11

they exchange nutrients, gases, waste, etc with the environment

Question 12

how are substances like nutrients, gases, and waste exchanged with the environment?

Answer 12

through a process that relies on their ability to dissolve in water and move across cell membranes

Question 13

what are the consequences of the exchange process on the body plan of animals?

Answer 13

the exchange influences the body plans

Question 14

what is the difference between coelomates and acoelomates?

Answer 14

coelomates have a body cavity that can accomodate internal organs while acoelomates lack a body cavity

Question 15

what is the hiearchial organization of animals?

Answer 15

starts with cells as the basic unit, groups of cells with similar structure and function make up tissues, different tissues organized into a functional unit are organs, organs that work together is an organ system

Question 16

what are the four main types of tissues in animals?

Answer 16

epithelial, connective, muscle, and nervous

Question 17

what are examples of homeostasis processes?

Answer 17

our bodies employ various strategies to maintain stability, or homeostasis, in response to changing external conditions. When it’s cold, we may shiver internally, generating heat through muscle contractions to maintain our internal body temperature. Conversely, when it’s hot, we might sweat externally, using evaporation to cool down and regulate our body temperature.

Question 18

what are two strategies used for the maintenance of homeostasis?

Answer 18

regulators and conformers, many animals will regulate some conditions and conform to others

Question 19

what is a regulator?

Answer 19

maintain internal conditions within a narrow range, regardless of external conditions. They use physiological mechanisms to control internal variables such as body temperature, blood pH, and ion concentrations. For example, humans are regulators of body temperature, maintaining it around 98.6°F (37°C) regardless of external temperature changes.

Question 20

what are conformers?

Answer 20

. They do not actively regulate internal variables but instead conform to the external environment. For example, some aquatic organisms, like fish, allow their body temperature to match the temperature of the water they are in.

Question 21

what are adaptions animals have for exchange with the environment?

Answer 21

branching, folding, internal fluids

Question 22

how are variables maintained for regulators?

Answer 22

variables are kept at or near a specific value called a set point or a normal range (variable has upper and lower limit) through negative feedback mechanisms

Question 23

what is the process of negative feedback in regulators?

Answer 23

when an internal variable deviates from the set point, a stimulus triggers a response that brings the variable back to its normal range. this process involves a sensor, control center, and response mechanism.

Question 24

what are the two systems that coordinate responses to stimuli?

Answer 24

endocrine and nervous

Question 25

how does the endocrine system coordinate responses to stimuli?

Answer 25

by signaling hormones

Question 26

how does the nervous system coordinate responses to stimuli?

Answer 26

by signaling nerve impulses

Question 27

what is required for coordination and control in animals?

Answer 27

all tissues, organs, and organs systems must work together

Question 28

what is endocrine regulation?

Answer 28

involves hormones and feedback regulation (mostly negative)

Question 29

what is a hormone?

Answer 29

long distance chemical signals that are released by specific cells and travel through the body and cause physiological responses

Question 30

what is the process of blood glucose regulation?

Answer 30

blood glucose level rises -> pancreas releases insulin -> target cells take up glucose and the liver converts glucose into glycogen -> blood glucose level falls -> the pancreas releases glucagon -> the liver breaks down glycogen and releases glucose into the blood

Question 31

what is insulins purpose in blood glucose regulation?

Answer 31

stores sugar

Question 32

what is glucagons purpose in blood glucose regulation?

Answer 32

releases sugar

Question 33

what is the pancreas purpose in blood glucose regulation?

Answer 33

makes hormones

Question 34

what is the livers purpose in blood glucose regulation?

Answer 34

stores glycogen