Homeostasis (Unit 4) chapter 9 Flashcards
(137 cards)
1
Q
refers to the body’s attempt to adjust to the fluctuating external environment
A
Homeostasis
2
Q
In other words the body tries to maintain a stable ______ environment.
A
internal
3
Q
There are many different systems all working together within the body to maintain its _______
A
internal balance
4
Q
Refers to extracellular fluid, which
consists of interstitial fluid (between cells and tissue) and blood plasma
A
The Internal Environment
5
Q
The volume, temperature, and chemical composition of our internal environment can change _____
A
quickly
6
Q
Body uses ______ to regulate its internal conditions.
A
many systems
7
Q
Organ Systems Involved in
Homeostasis
A
-nervous system
-endocrine system
-muscular system
-integumentary system
-excretory system
-reproductive system
8
Q
how does body regulate body temp?
A
evaporation of water helps
9
Q
hypothalamus regulates ____ and changes in ______
A
temperature and changes in osmotic pressure
10
Q
kidneys maintain
A
water balance
11
Q
pancreas regulates
A
blood sugar
12
Q
Take in, process and distribute nutrients and other chemicals; also dispose of wastes
A
All organ systems
13
Q
blood distributes _____ throughout the body
A
heat
14
Q
skeletal muscles contract and release _____
A
heat
15
Q
All organ systems synthesize nutrients and other molecules essential for __________
A
cellular function
16
Q
organ systems Respond to ______ in environment
A
changes
17
Q
Organ system Protects body from _____ and ______
A
injury
infection
18
Q
organ systems:
A
Reproduce
19
Q
Involve “detection” and “correction”
A
Homeostasis and Feedback
Mechanisms
20
Q
Homeostasis and Feedback
Mechanisms: Both _____ and _____ feedback mechanisms
A
positive
negative
21
Q
Primary mechanism of homeostasis
A
Negative Feedback
22
Q
negative feedback stimulus triggers a response that
_______
A
compensates for the change
23
Q
In the human body there are three main
components of homeostatic control
A
- Sensor (eg sensory neuron)
- Integrator (eg the brain)
- Effector (a muscle or gland)
24
Q
Integrator activates ______
A
effector
25
_____ gathers information and sends to the _____
Sensor
integrator
26
The integrator compares to set points (______________________)
optimal functioning conditions
27
Negative Feedback Mechanisms
in Animals (Diagram explained)
28
Examples of + feedback include __________
Child Birth and Ejaculation
29
Therefore the variable is moved _______ from the steady state.
farther away
30
_______ is a system which reinforces changes which are occurring
Positive Feedback
31
_______ is the maintenance of body temperatures within a range that enables cells to function properly
Thermoregulation
32
Optimal Internal Temperature ______ from species
to species.
differs
33
Human:
37oC
34
Animals absorb energy if they are _____ than their external environment and
release thermal energy if they are ______ than their environment
cooler
warmer
35
Energy exchange can occur through:
conduction, convection, radiation, and evaporation
36
These terms describe what happens to an organism’s internal temperature
Homeotherms and Poikilotherms
37
maintain a stable body
temperature regardless of the
environment
Homeotherms
38
body temperature varies
with the environment
Poikilotherms
39
maintain a constant* internal temperature by generating heat through an increase in cellular respiration
Endotherm
40
use external (environmental) mechanisms to control their temperature (ex. Fish, Reptiles, Insects etc.)
Ectotherm
41
Therefore:
Most endotherms are _______
Most ectotherms are ________
homeotherms
poikilotherms
42
So how do humans stay
warm/cool?
homeostasis diagram
43
As water freezes it forms
_______ which
rupture cell walls
sharp ice crystals
44
Water also expands
when frozen and when
this occurs in an
organism it can:
destroy many important body tissues
45
So how do wood frogs survive being frozen?
They produce antifreeze within cells to prevent freezing
(Glucose)
They also dehydrate cells to prevent ice from forming
46
daily/nightly periods of decreased
physiological activity resulting in lowered metabolism and temps to conserve energy
Torpor
47
eg. of torpor
Some birds, marsupials, mammals such as rodents and bats
48
torpor occurring over an extended period (weeks/months) during winter
Hibernation
49
torpor occurring over an extended
period during summer
Estivation
50
results from difference in solute concentration on two sides of membrane
Osmotic pressure
51
actively regulating water balance/osmotic pressure of bodily fluids and cells
Osmoregulation
52
Excretion: Certain _______, ______ and ______ compounds must
be eliminated
ions, toxins and nitrogenous
53
_____ needed for terrestrial
organisms to dissolve solutes
and then excrete
Water
54
What is regulted in Excretion
Ionic and pH balance and
osmotic concentration
55
Excretion involves what organs
Involves kidneys, bladder
56
Deamination: Amino acids contain amino groups—with ______
nitrogen
57
Converted into _______ which is toxic
ammonia
58
Must be dilute-_____ is lethal
-0.005mgL
59
Fish can:
remove ammonia directly into environment because of water surrounding them
60
Humans and terrestrial organisms need
water to ________ for storage until _____
dilute ammonia
excretion
61
_______ + _______ 🡪 urea
Bicarbonate + ammonia in liver 🡪 urea
62
____ = 100 000Xs less toxic than ammonia
Urea
63
Birds (and some other terrestrial
organisms…) create _____
instead—white part of bird poop!
uric acid
64
Antidiuretic Hormone:
______ = coffee =
makes you urinate
Diuretic
65
___ regulates osmotic pressure
ADH
66
ADH is A hormone produced in
_______, released
by _______
hypothalamus
pituitary
67
ADH Causes kidneys to
_________
increase water absorption
68
More ADH = more
________ urine
concentrated
69
ADH Conserves water (T/F)
TRUE
70
_________ detect water loss
Osmoreceptors
71
Less water intake = more ________ blood
concentrated
72
Water ______ out of cells into blood (to dilute the blood)
osmoses
73
Hypothalamus
_____—pituitary
releases more _____
shrinks
ADH
74
ADH makes ____ more
permeable to water
:. body retains ____
water
kidney
more
75
Kidneys regulate blood
pressure by
adjusting how much water there is
in your blood
76
_______ 🡪 increases
Na+ reabsorption
Aldosterone
77
Causes water to osmose
into the ____
blood
78
_____ 🡪 ______ 🡪______
🡪stimulates aldosterone release
Renin 🡪 angiotensinogen 🡪angiotensin
🡪stimulates aldosterone release
78
Decreased blood pressure is detected by ________ in kidney
osmoreceptors
79
Aldosterone = _________ in kidney = water reabsorption
higher Na+
80
There are two main functions of the excretory system:
-concentrate wastes and then excrete toxins into environment
-regulate fluids and water in the body
81
Unicellular organisms can excrete toxic wastes via
_____ directly with environment
diffusion
82
Ex. Paramecium have an internal environment that is ______ to their environment and hence use _____ ______ to pump water out actively in order to maintain _____ balance
hyperosmotic
contractile vacuoles
osmotic
83
Invertebrate Excretory
Systems (______)
Multicellular organisms need organ systems because:
Earthworm
they’re too large for diffusion to be efficient
84
Some invertebrates such as the earthworm have excretory
systems called _____ that expel wastes from the
body
metanephridia
85
The earthworm diagram
85
In each segment of the earthworm, ______ (blood and interstitial fluid) flows into the metanephridium; ions and
wastes are reabsorbed from _______ that reabsorb and
excrete wastes out of worms
hemolymph
nephridopores
86
Insects such as the grasshopper excrete wastes using a set of
organs called:
Malpighian Tubules
87
System of tubes that deliver wastes to intestines in insects via
reabsorption and excretion
Malpighian Tubules
88
The closed ends of the tubules are immersed in the
_______, the open ends empty into the instestines
hemolymph
89
Conserve water by excreting _______ wastes in the form of
an almost water-free paste of uric acid and crystals
nitrogenous
89
Birds and some reptiles are _________ vertebrates
Birds and some reptiles
89
The urine then travels to the _______ where cells reabsorb
most of the K+ and Na+ ions back into the hemolymph, water
also then moves by osmosis
intestines
89
Uric acid, ___ and ____ ions are secreted into the tubules
K+ and Na+
90
the grasshopper diagram
90
The solid white _______ waste that is left is expelled through
the anus
uric acid
91
The _____ play a crucial role in removing wastes, balancing blood pH and maintaining the body’s water balance
kidneys
91
This is excreted into the _____ (end of the digestive system)
91
Two kidneys, each with a mass of 150g; hold ____ of blood
volume
25%
92
The white substance in bird droppings is ________, the darker
substances is _____
uric acid
feces
92
The Human Excretory
System:
Vertebrate excretory
systems use specialized
tubules called ________
nephrons
92
Birds and reptiles that live
near or in salty
environments take in large
quantities of salt. They
excrete salt through:
through glands
on nose
92
know diagram and parts
93
Kidney filters waste from the blood and “clean” blood exits
kidney through the ______
renal vein
93
Anatomy of the Kidney
Outer layer =
renal cortex
94
Blood is supplied to kidney through _______
renal artery
94
Each kidney contains
millions of ______
nephrons
95
Middle layer =
medulla
95
Renal pelvis 🡪 ______ 🡪 ________
Renal pelvis 🡪 ureter 🡪 urinary bladder
95
Nephron is the functional
unit of the ____
kidney
96
Blood enters nephron through ___________ and collects in
________ (a capillary bed)
afferent arteriole
glomerulus
96
Initial wastes (filtrate) move from the bloodstream into the hollow,
wrench shaped structure of the nephron called the ________
Bowman’s Capsule
96
Filtrate enters the ________
Proximal tubule
96
________ _________ surround the entire nephron to reabsorb
substances back into the blood
Peritubular capillaries
97
____ is formed in the nephron tubes
Urine
98
Collecting ducts drain into the _____ _______
renal pelvis
98
________ drains the urine into collecting ducts
Distal tubule
98
Urine leads to ureters then _______
bladder
98
___________ where useful substances are reabsorbed into
bloodstream
Loop of Henle
99
The process in which fluid and small molecules pass into the
Bowman’s capsule is known as ________
filtration
99
The Formation of Urine
Three steps:
1. Filtration
2. Reabsorption
3. Secretion
99
Blood fluids move from afferent arteriole in the _________
(high pressure capillaries)
glomerulus
99
____, _____, ______, ________, ___ diffuse from the blood
into the nephron (urine is called the filtrate)
H2O, NaCl, glucose, amino acids, H+
100
Solutes move into Bowman’s Capsule (_____ to _____ pressure)
high to low
101
____, ____, ______ do not leave the blood
proteins, RBCs, platelets
102
Filtration diagram
102
_________ is the transfer of water, ions and nutrients back
to the interstitial fluid by passive and active transport
Reabsorption
102
Only ___ mL of urine is produce per 120mL of filtrate entering
nephron
1
102
This transport results in:
hypoosmotic filtrate
103
Water follows—osmoses into ____________ (aquaporins also
allow more of this)
interstitial fluid
104
Filtrate moves into Loop of Henle
________: More water reabsorbed
_________: Na+ and Cl- reabsorbed
Descending
Ascending
104
Distal tubule
______ + salts reabsorbed
Water
104
Reabsorption diagram
104
_________ is the removal of wastes from the blood and
interstitial fluid into nephron
Secretion
105
Occurs in the _____, ________ tubules and
________ ducts
proximal, distal convoluted and collecting
105
Nitrogen containing wastes, excess H+, detoxified poisons
(ex. _______ ________...), K+ and other mineral
concentrations are balanced via secretion
Alcohol, medications
105
Urine Formation diagram
