bio exam 5 Flashcards
(182 cards)
1
Q
anatomy definition
A
the study of the structure of body parts and their relationship to one another
2
Q
physiology definition
A
the study of the function of body parts; how they work to carry out life-sustaining activities
3
Q
5 levels of organization and describe them
A
- chemical level:
atoms–>biological molecules - cellular level:
cells –> tissues - tissue level:
tissues –> organs - organ level:
organs –> organ systems - organ system level:
11 organ systems –> entire living thing (organism)
4
Q
tissue definition
A
a group of related cells working together to perform a common function
5
Q
organ definition
A
a collection of tissues that form a body structure specialized to carry out a specific part of a complex physiological function
6
Q
organ system definition
A
a group of organs that work together to regulate or perform one or more complex physiological functions
7
Q
homeostasis definition
A
physiological process where our systems work together to keep the internal environment of the body constant, even if our external environment changes
8
Q
dynamic steady state definition
A
constantly in motion / has an average value
9
Q
set point definition
A
the average value for a control system
10
Q
2 major functions of a homeostatic control system
A
- positive feedback control
- negative feedback control
11
Q
elements of a homeostatic control system
A
- stimulus
- receptor
- incoming signal
- controller
- outgoing signal
- effector
- response
12
Q
definition of each element of homeostatic control system and how are they connected
A
- stimulus:
- any change in the internal or external environment that can be detected by a receptor - receptor:
- specialized to sense specific kinds of stimulus
- sends an incoming signal that communicates the stimulus to a controller - incoming signal
- controller:
- receives the incoming signal about the stimulus
- then uses that signal to decide how they respond
- after processing the incoming stimulus signal, the controller sends an outgoing signal to effector - outgoing signal:
- tells the body how to respond - effector:
- carries out the bodys response - response
13
Q
how are the receptor, incoming signal, and controller slightly different in chemical homeostatic systems than in other types of control systems
A
the receptor and controller are the same body structure; in these cases the incoming signal is always a signal created inside of the cells of the body structure
14
Q
positive vs negative feedback: how common are they in response in homeostasis
A
positive - much less common
negative - most systems
15
Q
positive vs negative feedback: does the response reduce or amplify the stimulus
A
positive - amplifies stimulus
negative - shuts off stimulus
16
Q
positive vs negative feedback: does the system move the body closer or further away from the set point
A
positive - further
negative - closer
17
Q
positive vs negative feedback: what is the advantage of the system
A
positive - quick
negative - self-regulates
18
Q
osmoregulation definition
A
the process by which an organism controls the concentration of both water and dissolved molecules in its body
19
Q
electrolyte definition
A
substances that separate into ions when dissolved in water
20
Q
osmotic stress definition
A
when the water or electrolyte imbalance disrupts the metabolic processes of the cell
21
Q
osmolarity definition
A
the concentration of all dissolved solutes that can cause osmosis
22
Q
hypertonic definition
A
concentration of solutes is higher on the outside of the cell (high osmolarity)
23
Q
hypotonic definition
A
concentrations of solutes is higher on the inside of the cell (low osmolarity)
24
Q
osmoconformer definition
A
have the same osmolarity as their surrounding environment
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osmoregulator definition
have a different osmolarity than their surrounding environment
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which animals are osmoconformers
- marine invertebrates
- marine fish with cartilage-based skeletons
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which animals are osmoregulators
all animals (that are not marine invertebrates or marine fish with cartilage-based skeletons)
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what are the osmotic stresses and imbalances in marine fish; how do they balance with osmoregulation
stress: hypertonic sea environment
balance: drink seawater and produce little urine
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what are the osmotic stresses and imbalances in freshwater fish; how do they balance with osmoregulation
stress: hypotonic environment
balance: drink small amounts and produce large amounts of urine
30
how are the fish that are both marine and freshwater able to osmoregulate in both types
they can swap the location of their active transport:
marine environments: inside of gill cells, pump electrolytes out of body
freshwater environments: outside of gill cells, pump electrolytes back into the body
31
what are the different osmotic stresses and imbalances (water and electrolyte losses/gains) in terrestrial animals
water loss:
- breathing
- body surface exposure to air
- feces and urine
electrolyte loss:
- drinking
- urine
water gain:
- eating and drinking
- metabolism (dehydration synthesis provides water the body can use)
electrolyte gain:
- food
32
retention definition
the act of absorbing a substance back into the body before it is excreted
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filtration definition
involves separating the water-based fluid of the body from the cells and other large molecules
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reabsorption definition
involves selectively absorbing the parts of the filtered material that we want to retain
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how do insects prevent water loss and perform osmoregulation using the Malphigian tubules and hindgut
- primitive kidneys (melphigian tubules) in direct contact with hemolymph (insect blood)
- removes only electrolytes, water, and waste products from hemolymph by acting as a filter
- empties filtered material directly into gut
- end of digestive tract (hindgut) reabsorbs what needs to be retained
- waste is removed as feces
36
what does the kidney do in osmoregulation
performs filtration and absorption in mammals
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how does the kidney do what it does in osmoregulation (hint: filtration and reabsorption)
- blood enters kidney
- most blood plasma (water based blood) is separated from blood by kidney
- kidney reabsorbs most of the water, electrolytes, and non-waste molecules into the blood
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kidney definition
the organ that performs filtration and absorption in mammals
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renal artery definition
what the blood enters the kidney through
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renal vein definition
where the freshly processed blood leaves the kidney through
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ureter definition
where the material that is not reabsorbed and becomes urine leaves through
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urinary bladder definition
where urine is stored until the body is ready to excrete it
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3 major regions of the kidney
1. renal cortex
2. renal medulla
3. renal pelvis
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what happens in the renal cortex of the kidney
where the majority of filtering units (nephrons) can be found
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what happens in the renal medulla of the kidney
where filtered blood plasma is concentrated into its final form (urine)
46
what happens in the renal pelvis of the kidney
catches urine as it is produced in the renal medulla and funnels it into the ureter
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nephron definition
tube-shaped filtering units in the kidney; uses active transport, diffusion, and osmosis to reabsorb filtered plasma back into the blood
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medullary gradient definition
allows the kidney to remove large volumes of water and electrolytes from the blood
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5 major sections of the nephron
1. renal corpuscle
2. proximal tubule
3. loop of Henle
4. distal tubule
5. collecting duct
50
what does the renal corpuscle do and how
where plasma is filtered out of the blood;
- filtration caused by blood pressure
- pushes plasma through holes in glomerulus
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glomerulus definition
a network of tiny blood vessels inside the corpuscle; has a series of tiny holes that only allows blood plasma and the electrolytes and small molecules in it to leave
52
what force pushes filtration on the glomerulus
blood pressure
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how can imbalances of blood pressure cause kidney problems
- long term high blood pressure damages corpuscle and can cause kidney failure
- short term low blood pressure stops the filtration process and allows toxic waste products to build up in the body
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obligatory reabsorption definition / where it happens in the nephron
90% of the pre-urine is automatically reabsorbed; happens in the proximal tubule and loop of Henle
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what does the proximal tubule do during obligatory reabsorption and how does that happen in each section
uses active transport, diffusion, and osmosis to selectively reabsorb 2/3 of all materials in the pre-urine
- reabsorbs some of the water and electrolytes
- reabsorbs all of the nutrients and vitamins
- pre-urine that leaves proximal tubule contains water, electrolytes, and waste products
56
what does the loop of Henle do during obligatory reabsorption and how does that happen in each section
reabsorbs water and electrolytes entirely by diffusion and osmosis
- pre-urine goes down descending limb and encounters high osmolarity and water leaves the pre-urine by osmosis
- pre-urine goes up ascending limb and encounters low osmolarity and electrolytes leave pre-urine by diffusion
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descending limb definition
first half of loop of Henle; only permeable to water
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ascending limb definition
second half of loop of Henle; only permeable to electrolytes
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regulated reabsorption definition / where it happens in the nephron
the remaining pre-urine (that isnt absorbed by obligatory reabsorption) is regulated by homeostasis; happens in the distal tubule and collecting duct
60
what does the distal tubule do in regulated reabsorption and how is it regulated by aldosterone levels
reabsorbs the electrolytes sodium and chloride by active transport;
- amount reabsorbed is regulated by aldosterone
- if sodium is low, high aldosterone is released --> causes distal tubule to reabsorb more sodium and chloride
- if sodium is high, low aldosterone is released --> causes distal tubule to reabsorb less sodium and chloride
61
what does the collecting duct do in regulated reabsorption and how is it regulated by ADH levels
reabsorbs water;
- reabsorption amount is regulayed by ADH
- water levels low, high ADH is released --> causes collecting duct to reabsorb more water
- water levels high, low ADH --> causes collecting duct to reabsorb les water
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gas exchange definition
the process of moving gases across one or more cell membranes
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why must animals acquire oxygen and excrete carbon dioxide
animal cells have an aerobic metabolism, meaning the final electron acceptor in the electron transport chain is oxygen gas; pyruvate processing and the citric acid cycle produces carbon dioxide gas as a waste product
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respiratory surface definition
the designated spot in the body where to limit the loss of water and electrolytes, gas exchange with the environment takes place
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respiratory system definition
the group of organs and body structures that contain and protect the respiratory surfaces
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circulation definition
movement of gasses in dissolved in a fluid
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blood definition
the fluid in vertebrates that gasses are moved in
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hemolymph definition
the fluid in invertebrates that gasses are moved in
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circulatory system definition
the organs and body structures involved in moving blood/hemolymph through the body
70
which rules govern the movement of gases into and through the body
rules of diffusion
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pressure gradient definition
what the diffusion of gasses is driven by
72
partial pressure definition
the percentage of the total pressure represented by each gas
73
Fick's Law of Diffusion
- law that governs how fast molecules diffuse
k * A * (P2-P1 / D)
-k = constant specific to each gas
-A = surface area available for gas exchange
-D = distance that the gas must diffuse
-P2-P1 = partial pressure gradient
74
how do surface area (A), diffusion distance (D), and pressure gradients influence rate of diffusion
- A: directionally proportional
- D: inversely proportional
75
2 major tasks of a respiratory system
1. ventilation
2. gas exchange
76
which direction do oxygen and carbon dioxide move through a respiratory surface
oxygen: diffuses into the blood
carbon dioxide: diffuses into the environment
77
how does ventilation and gas exchange happen in fish
as water flows over gills, oxygen diffuses into blood and carbon dioxide diffuses out
78
how does buccal pumping work
- during inhalation, the gill covers (operculum) are closed and the fish puts water into its mouth
- during exhalation, the mouth squeezes the water which pushes the water over the gills and out through the open operculum
79
how does ram ventilation work
the fish swims with its mouth open, allowing water to flow directly over the gills and out of the operculum
80
what is the basic structure of a gill
- each gill is divided into several arches, with each arch having thousands of gill filaments
- gills filaments increase surface area
- each filament contains thousands of blood vessels that carry blood close to gill surface (decreasing D)
81
how do ventilation and gas exchange happen in terrestrial invertebrates
- use an internal tracheal system for gas exchange
- ventilation of the tracheae happens because of physical movement
- contraction of muscles squeezes tracheae which pushes air out of body
- relaxation of muscles opens tracheae which pulls air into body
82
how is the tracheal system structured
it is spread throughout the entire body, with the openings protected and restricted by spiracles which can be opened and closed
83
what is a spiracle for
protecting and restricting openings of the tracheal system
84
how is the tracheal system ventilated
physical movement
85
how does ventilation and gas exchange happen in terrestrial vertebrates with lungs
lungs are the respiratory surface
86
how are the lungs structured
(human lungs)
- branch extensively
- each branch ends in alveolus (150 mil per lung)
- very thin alveolus
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what is an alveolus
small respiratory membrane at the end of each branch in the lung
88
how do the lungs increase surface area and decrease diffusion distance
the millions of alveoli increase surface area, the incredibly thin and in most spots there are only 2 thin cells that separate blood from air, decreasing distance
89
how does the diaphragm create air pressure gradients during inhalation and exhalation
it contracts and pulls downwards, creating an area of low pressure inside the lungs (negative pressure), which pulls air into the lungs during inhalation. when it relaxes, it pushes upward creating high pressure, pushing air out of the lungs during exhalation
90
how and where is ventilation regulated in humans
the brainstem senses carbon dioxide concentration in the fluid that surrounds it
- CO2 too high, increases ventilation rate
- CO2 too low, decreases ventilation rate
91
complete homeostatic control system (sensor, incoming signal, controller, outgoing signal, effector) that regulates ventilation and what kind of feedback the system uses
stimulus: carbon dioxide concentration
receptor: brainstem
incoming signal: intracellular signal
controller: brainstem
outgoing signal: nerve signal
effector: diaphragm
feedback: negative
92
how are oxygen and carbon dioxide carried in the blood
circulation
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what does hemoglobin do
the oxygen-binding protein in vertebrates to carry oxygen
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what does hemocyanin do
a common type of oxygen-binding protein in invertebrates
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what does carbonic anhydrase do
it is an enzyme that performs a chemical reaction that converts carbon dioxide and water into carbonic acid
96
how do carbonic anhydrase and carbonic acid mean that we can regulate our blood pH by changing our breathing rate
the presence of them mean that carbon dioxide levels in the blood regulate pH, and we can lower the pH by lowering breathing rate
97
how does gas exchange occur in a typical invertebrate
- oxygen and carbon dioxide exchange directly between the air and the hemolymph throughout the body
- the oxygen binds to the hemoglobin or hemolymph
- carbonic acid is converted back to carbon dioxide by carbonic anhydrase
- carbon dioxide diffuses out into the hemolymph into the air
98
why does the gas exchange system in invertebrates mean that they do not need a complex circulatory system
gas exchange can occur throughout their entire body
99
how does an open circulatory system work
the fluid that carries gasses is not enclosed inside blood vessels and hemolymph is pumped by movement or one-chambered heart
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what is a closed circulatory system
blood is contained in blood vessels, with a muscular heart needed to pump the blood
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what does a muscle heart do
provides the pressure needed to push the blood through the system of vessels
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what does the atrium do
receives blood
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what does the ventricle do
applies pressure to and pumps blood
104
5 types of blood vessels
1. arteries
2. arterioles
3. capillaries
4. venules
5. veins
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order that blood passes through the types of blood vessels, starting with the heart
1. arteries
2. arterioles
3. capillaries
4. venules
5. veins
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artery function
carry blood away from the heart
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vein function
carry blood to the heart
108
capillary function
maximize how much gas can be exchanged by diffusion
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3 reasons why vertebrates have a closed circulatory system (explain)
1. body size: larger body needs more efficient way to deliver gasses
2. activity level: increased activity level requires more energy, which needs more oxygen delivery to muscles
3. development of the gill/lung: having a single organ needs a system that can move oxygen from the gill or lung more quickly and efficiently
110
how does the simple closed circulatory system of the fish work
- atrium of the heart receives blood low in oxygen
- atrium squeezes blood into ventricle
- ventricle pumps blood to gills
- in gills, blood absorbs oxygen and releases carbon dioxide
- blood travels from gills to rest of body where it releases oxygen and absorbs carbon dioxide
- blood returns to atrium of the heart
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what is a circuit in the circulatory system
a complete circular pathway of blood flow from heart to body back to heart
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why do land animals need 2 circuits in their circulatory system
one pumps low oxygen blood to lung, other pumps high oxygen blood to rest of the body
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what does the pulmonary circuit do; is it high or low pressure
to the lungs; low pressure
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what does the systemic circuit do; is it high or low pressure
to the rest of the body; high pressure
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what does the superior vena cava do
where the blood from the head and arms goes to the heart through
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what does the inferior vena cava do
where the blood from the torso and legs goes to the heart through
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what does the right atrium do
where the blood from the superior and inferior vena cava enter to
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what does the right ventricle do
where the blood from the right atrium moved to
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what do the pulmonary arteries do
where the blood is pumped by the right ventricle to the lungs through
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what do the pulmonary veins do
bring high oxygen blood from the lungs back to the heart
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what does the left atrium do
where the blood from the pulmonary veins enters
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what does the left ventricle do
where the blood moves from the left atrium to
123
what does the aorta do
a large artery that the left ventricle pumps blood to the systemic circuit through
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what is the order that blood flows through the heart
1. right atrium
2. right ventricle
3. -->lungs-->
4. left atrium
5. left ventricle
6. aorta
125
sinoatrial node definition
the special structure at top of the right atrium where the electrical signals that control heart pumping start
126
atrioventricular node definition
the structure where the signal is delayed for a fraction of a second
127
ventricular conducting fibers definition
where the signal spreads through the left and right ventricles
128
how do electrical signals spread through the heart from where they start in the sinoatrial node to what happens when they fade away
1. signal originates at SA node
2. signal spreads over atria; atria contract
3. signal is delated at AV node
4. signal spreads
5. ventricles relax
when signal fades away, both ventricles relax and the cycle begins again
129
why is the sinoatrial node called the pacemaker of the heart
because the heart beat starts with electrical signals from the SA node, it sets how fast the heart will beat
130
how do nerve and muscle cells send electrical signals
manipulating the charged ions
131
5 gradients of ions discussed
1. sodium (+)
2. calcium (+)
3. chloride (-)
4. potassium (+)
5. the cells proteins have an overall negative charge (-)
132
which gradients of ions can diffuse and which direction will they diffuse when the membrane is permeable to them
sodium: down gradient to ICF
calcium: down gradient to ICF
chloride: down gradient to ICF
potassium: down gradient to ECF
protein: no diffusion
133
how is the charge on a membrane discussed
in terms of what electrical charge is on the inside of the membrane
134
how and why does diffusion of sodium ions change the membranes charge
positive charges diffuse into the ICF
135
how and why does diffusion of potassium ions change the membranes charge
positive charges diffuse into the ECF
136
how and why does diffusion of chloride ions change the membranes charge
negative charges diffuse into the ICF
137
polarized definition
when diffusion charges a membrane
138
membrane potential definition
the strength of the charge on a membrane
139
resting membrane potential definition
the polarization of every single cell on the body
140
be able to interpret a membrane potential value (what does saying that a membrane potential is -70mV mean)
- sign tells you what charge is on the inside of the membrane
- number tells you the strength of the charge
141
what do sodium leak channels do
open and close randomly which makes it so the membrane is always permeable to sodium
142
what do potassium leak channels do
open and close randomly which makes it so the membrane is always permeable to potassium
143
how is the resting membrane potential set by sodium and potassium leak channels
there are many more potassium leak channels, making the resting membrane potential typically negative
144
why do different cell types have different resting membrane potentials
there are different ratios of leak channels in different types of cells
145
what are gated ion channels
channels that are normally closed and only open in response to some kind of signal
146
trace definition
the chart we use to track changes in membrane potential
147
be able to identify the resting membrane potential on a trace
trace starts at the resting membrane potential, moving up with a more positive and moving down with a more negative voltage
148
3 different types of gated ion channels and what causes their gates to open
1. chemically gated ion channels: when a chemical signal binds to them
2. mechanically gated ion channels: when a physical pressure is applied to their cell membrane
3. voltage gated ion channels: in response to a change in membrane potential
149
what special function can we perform with voltage gated ion channels that we cant perform with the other types
they can be activated in chains to produce complex electrical signals called action potentials
150
3 types of membrane potential changes; which kind of channels can cause each
1. depolarization
- sodium
- calcium
- positive ions
2. repolarization
- potassium
3. hyperpolarization
- potassium
- chloride
151
basic structure of a neuron
1. dendrites
2. cell body
3. axon
152
dendrites function
receptors that receive chemical or physical signals
153
axon function
generates and transmits electrical signals called action potentials along the axon membrane
154
cell body function
integrates all of the electrical signals it receives
155
synapse function
allows the neutron to communicate with the cell it connects to
156
what happens at a synapse
the cells that each axon terminal makes a connection with one or more of
157
how do nerve cells communicate with the cells they connect
synapse
158
neurotransmitter definition
the chemical signals that the axon releases into the synapse
159
how can the dendrites receiving signals cause action potentials to happen in the nerve cell
when dendrites receive a signal, it causes small disturbances in the membrane potential, which can trigger an action potential
160
what is the threshold potential
the point that the disturbance in membrane potential has to be to trigger an action potential
161
key physiological behaviors of action potentials
1. action potentials must be triggered by a stimulus
2. action potentials are all-or-none
3. action potentials are non-decremental
4. action potentials are irreversible
162
what do each of the key physiological behaviors of action potentials mean for the behavior of an action potential
stimulus: dependent on receiving a chemical or physical signal
all-or-none: identical and do not vary in strength or size
non-decremental: do not get weaker with distance
irreversible: continues nonstop until the action potential completes
163
2 kinds of channels used to create an action potential and the states they can be in and what happens when they are in those states
1. voltage-gated potassium channel
2. voltage-gated sodium channel
164
4 stages of an action potential and what state the sodium and potassium channels are in each
1. resting stage
- all: closed
2. depolarization
- sodium: open
3. repolarization
- sodium: inactive
- potassium: open
4. hyperpolarization
- sodium: reset
- potassium: closed
165
what changes in membrane potential cause the shift from each stage to the next
threshold reached --> depolarization
+35 mV --> repolarization
resting potential reached --> hyperpolarization
--> slowly rise back up to resting
166
absolute refractory period definition
the period of time where a cell cannot start a new action potential until the last one completes
167
how do sodium channels prevent a second action potential from starting before the first one completes
the absolute refractory period
168
2 types of axons
1. myelinated axons
2. unmeylinated axons
169
how are the 2 types of axons different from each other
myelinated axons have a cell-based covering, while unmeylinated axons have no coverings
170
how are action potentials conducted along an axon (eg in one direction, starting from the initial segment to the axon terminal)
action potential travels in one direction along the neuron membrane until it reaches the end of the axon
171
how does diffusion of sodium ions cause conduction
diffusion of sodium ions raises the membrane potential until above threshold potential, then will fire an action potential, and is repeated until the action potential reaches the end of the axon
172
why do action potentials not trigger in both directions in an axon (hint- sodium channels)
the sections of the axon close behind it are in their refractory period (sodium channels are inactivated)
173
continuous conduction definition
when the action potential must conduct in a straight line down the entire length of the axon
174
saltatory conduction definition
the action potential appears to jump from node to node
175
which types of axons perform continuous conduction
unmyelinated axons
176
which types of axons perform saltatory conduction
myelinated axons
177
how does saltatory conduction work in myelinated axons
the sodium and potassium channels of the action potential are all crammed into nodes, making the concentration gradient of sodium between the nodes much larger
178
how do saltatory and continuous conduction differ in speed and why
saltatory conduction is much faster because of its larger gradient
179
synaptic vesicles definition
the small bubbles of membrane that contain neurotransmitters in each axon terminal
180
neuroternsmitter definition
contained in synaptic vesicles
181
step-by-step process of nerve signaling
1. action potential is conducted to the axon terminal
2. depolarization phase triggers opening of a voltage-gated calcium channel
3. the open calcium channel allows calcium to diffuse into the cell
4. calcium signal inside of the cell causes synaptic vesicles to combine with the nerve membrane
5. fusion of the vesicles releases the neurotransmitter into the synaptic cleft
6. released neurotransmitter will bind to a receptor on the post-synaptic cell
7. neurotransmitter binding to the post-synaptic cell will cause a physiological change
182
what kind of physiological changes can happen in the cell a nerve connects to when a neurotransmitter is released (hint - depends on if it is a muscle gland or nerve cell)
muscle: contract to cause movement
gland: release a secretion or a hormone
nerve: send an action potential signal
