1
Q
Complex Multicellular Features
A
- Highly developed mechanisms for adhesion
- Specialized structures for cell communication
- 3-D organization (not all cells in direct contact w/ environment)
- Require mechanisms for transferrring signals
2
Q
Surface Area & Volume
A
As organisms get bigger, surface area and volume both grow
Surface / volume ratio shrinks
As SA decreases, more limited by diffusion
4
Q
Diffusion Limits
A
- Size must be small for diffusion to meet needs
- Not a lot of storage space for NRG
- Small range of environments
- Reproduce quickly and often
5
Q
Evolve Multicellularity Pros
A
- Longer life span
- Cells specialize and are more efficient
- Bigger is better
- Injuries can be sustained
- Harder to prey upon
- Sexual reproduction: increased genetic diversity
6
Q
Evolve Multicellularity Cons
A
- Increased energy requirements.
- Can no longer rely on osmosis and simple diffusion
- Longer time to reach adulthood/reproduce
- Infections
- Variety of challenges to overcome…
6
Q
Ganglia
A
Groups of nerve cell bodies that process sensory information
7
Q
Properties of Simple Multicellular Organisms
A
- Adhesion molecules that cause adjacent cells to stick together
- Little communication or transfer of resources between cells and little differentiation of specialized cell types.
- Most or all of the cells retain a full range of functions including reproduction.
- Every cell is in contact with the external environment.
8
Q
Cephalization
A
Concentrating sensory organs and nervous system components at the front of the body
9
Q
Neurons
A
Basic functional unit of nervous system
10
Q
Nervous System
A
- Network of many interconnected nerve cells
- Sense and respond to the environment
- Coordinate action of muscles
- Control internal function of body
11
Q
Sensory Neurons
A
- Send and receive information about an animal’s environment or its internal physiological state
- Respond to physical features such as temperature, light, and touch or to chemical signals such as odor and taste.
12
Q
Interneurons
A
- Process the information received by sensory neurons and transmit it to different body regions, communicating with motor neurons at the end of a pathway
13
Q
Motor Neurons
A
Produce suitable responses by stimulating muscles.
14
Q
Axon Terminal
A
Communicates with neighboring cell through junction (synapse)
15
Q
Synaptic Cleft
A
Separates end of axon of presynaptic cell and neighboring postsynaptic cell
16
Q
Neurotransmitters
A
Convey the signal from the end of the axon to the postsynaptic target cell.
17
Q
Signal Transmission
A
- Stimuli Received by Dendrites and Cell body
- Stimuli summoned at axon hillock (Action Potential triggered if signal is strong enough)
- Action potential conducted to axon terminal –> release of neurotransmitters
- Bind to receptors on postsynaptic cell –> new signal in postsynaptic neuron
18
Q
Threshold
A
Input depolarizes cell above threshold potential
Sends Action potential
19
Q
Depolarization
A
Increase in membrane potential
Na+ ions enter the cell (voltage-gated channels)
Causes positive charge, and membrane potential rises
Action potential fired at axon hillock
20
Q
Repolarization
A
Caused by Na+ channels closing and K+ channels opening
Membrane potential rapidly falls as K+ ions leave the cell
Falls below the resting potential
21
Q
Refractory Period
A
Can’t fire action potential
The K+ channels are still closing
Returns to resting as K+ ions are returned via pumps
22
Q
Myelin Sheath
A
Insulates axon’s membrane
Spreads charge a greater distance on the axon
23
Q
Glial Cell
A
Surround neurons and provide them with nutrition and physical support
Orient neurons as they develop their connections
24
Q
Astrocytes
A
Type of Glial Cell
Contribute to blood-brain barrier
Clear neurotransmitters btwn synapses
Glial scar and repair damage
Component of Central Nervous System
25
No Summation
EPSPs widely spread don't set off Action Potential
26
Temporal Summation
Multiple EPSPs arrive quickly at a single synapse and set off an action potential
27
Spatial Summation
EPSPs at 2 or more different synapses set off an action potential
28
Cancellation
An EPSP and IPSP cancel each other out (no action potential)
29
Somatic (Voluntary) Responses
- Conscious rxns
- Sense and respond to environment
- Sight, smell, sound
- Motor neurons that excite muscles --> contraction
30
Autonomic (Involuntary) responses
- Unconscious rxns
- Regulate internal body functions that maintain homeostasis
- Sympathetic and parasympathetic
31
Parasympathetic
Rest and digest
Conserves NRG, slows heart rate, increases intestinal and gland activity, relaxes sphincter muscles
32
Sympathetic
Fight or flight
33
Afferent Neurons
Send information towards Central Nervous System
34
Efferent Neurons
Send information away from Central Nervous System
35
Chemoreceptors
Respond to molecules that bind to specific protein receptors on the cell membrane
1. Molecule binds to protein receptor (protein receptor changes shape)
2. Na+ channels open through G Protein transduction pathways
3. Depolarization of cell
4. Release of neurotransmitters
36
Mechanoreceptors
Respond to physical deformations of their membrane produced by touch, stretch, pressure, motion, and sound
1. Deformation of receptor membrane opens Na+ channels (depolarization)
37
Photoreceptors
1. Respond to photons of light NRG
2. Close Na+ channels
3. Cell is hyperpolarized
4. Inhibit firing rate of other neurons within the eye
38
Electroreceptors
Detect weak electrical signals emitted by organisms
In fish and monotremes
39
Thermoreceptors
Respond to heat and cold to control body temp and homeostasis
40
Nociceptors
External and internal
Respond to pain
Respond to noxious signals
41
Lateral Inhibition
Enhances strength of sensory signal but diminishes it peripherally
Inhibit neurons that receive signals from adjacent regions but send excitatory signals to interneurons within local region
Know exactly where something is interacting with our body
42
Smell
43
Smell
44
Multicellular Organism
Highly developed mechanisms for adhesion
Specialized structures for communication
Tissue + organ differentiation
3d
45
Connective Tissue
fat, bone, cartilage support/protection
46
Epithelial Tissue
Covers our bodies surfaces
47
Muscular Tissues
skeletal, smooth, cardiac
48
Nervous Tissue
Conduct Signals
49
Organ
Made of tissues
| Performs a definite function
50
Organ System
Group of organs that each contribute to the function of the body as a whole
51
Bulk transport
Deliver substance over large distances
52
PNS
Sensory and motor nerves
53
CNS
Brain and spinal chord
54
Dendrite
Receive info
55
Axon
Transmit Info
56
Synapse
Junction btwn cells
57
Membrane Potential
The charge difference between the inside and the outside of a neuron due to differences in charged ions
58
Ganglia
Group of nerve bodies that process sensory information
59
Node of Ranvier
Where the axon is exposed
60
Saltatory Propagation
Action potentials jump from node to node
61
Voltage Gated Channels
Open and close in response to change in membrane potential
62
Reciprocal Inhibition
Inhibit activity of opposing muscles
| Flexing your knee
63
Sensory Organ
Converts physical and chemical stimuli into nerve impulses.
64
Sensory Transduction
The conversion of physical or chemical stimuli into nerve impulses
65
G Protein Coupled Receptor
When the extracellular receptor binds its ligand it changes shape causeing the G-protein to become phosphorylated (GTP) giving it energy.
66
Taste bud
Cluster of chemosensory receptor cells
67
5 Flavors
```
Sweet
Sour
Bitter
Salty
Savory
```
68
G Protein coupled tastes
Sweet, bitter, savory
69
Stereocilia
Small, nonmotile projections
| Line cell surface
70
Statocysts
Gravity Sensing Organs
| Internal chambers lined by hair cells with stereocilia that project into the chamber
71
Statolith
A dense particle of mall granules of sand or other material
| Free to move within the statocyst organ.
72
Hair cell
Sense movement and vibrations via mechanical vibrations
73
Vestibular System
Senses motions of the head and its orientation with respect to gravity
74
Outer Ear
Pinna
Ear Canal
Tympanic Membrane (Eardrum)
Transmits airborne sounds into ear
75
Middle Ear
3 small bones
| Amplify waves that strike eardrum
76
Vestibulocochlear Nerve
Vestibular and cochlear branches
77
Inner
Cochlea
78
Cochlea
Coiled chamber within the skull that contains hair cells that convert pressure waves into an electrical impulse that is sent to the brain.
Has upper and lower canal separated by basilar membrane and cochlear duct
79
Tectorial Membrane
Formed by stereocilia
| Doesn't move
80
Organ of Corti
Contains specialized hair cells with stereocilia
81
Retinal
Light absorbing pigment
| changes conformation when it absorbs a photon
82
Opsin
Light sensitive protein that converts light energy into electrical signals in the receptor cell.
83
Fovea
Cone cells concentrated
Center of visual field
84
Ciliary Muscle
Contraction and relaxation adjust shape of lense
Focus light images
85
Iris
Opens and closes to adjust amount of light that enters through the pupil
86
Rods
Black/white
| Perephrial
87
Cones
Color vision
88
PDE
Hydrolyzes cGMP --> Close Na channels
89
Bipolar Cells
Adjust their release of neurotransmitters in response to the input from multiple rod and cone cells.
90
Ganglion Cell
transmit action potentials via the optic nerve to the visual cortex in the brain.
91
Horizontal Cell
Enhances contrast through lateral inhibition to sharpen the image
92
Amacrine Cell
Enhances motion detection and adjusting for changes in illumination
93
Forebrain
governs advanced cognitive functions
94
Hindbrain
controls body functions and behaviors
95
Cerebellum
Coordinate complex motor tasks
| Integrates motor and sensory info
96
Medulla oblongata
Center for respiration and circulation
| Regulate breathing, heart and blood vessel function
97
Cerebrum/Cerebral Cortex
```
Outer layer (grey matter)
Inner layer (white matter) = axons
```
Initiates and coordinates movement, regulates temp
98
Frontal Lobe
Decision making, taste, smell
99
Parietal Lobe
Body and spatial awareness
100
Occipital Lobe
Process visual info
101
Temporal Lobe
Process sound and speech
102
Primary Motor Cortex
muscle movement in response to PSC
103
Primary Sensory Cortex
takes in tactile info (vibrations, pain, temperature)
104
Hippocampus
Long term memory fuction
105
VTA
Sends domine to the amygdala, hippocampus, N accumbens, prefrontal cortex
106
Amygdala
Emotion
107
Prefrontal Cortex
Focus
108
Dopamine
Makes you feel happy
109
Serotonin
Makes you feel satiated
110
synaptic plasticity
Ability to adjust synaptic connections between neurons
111
Electroencephelogram
Detect brain activity by measuring electrical impulses
112
Beta, Alpha, Delta, Theta Waves
```
Beta = alert
Alpha = light meditation
Theta = drowsy
Delta = deep sleep
```
113
4 Stages of Sleep
N1 = light sleep
(between being awake and falling asleep)
N2 = onset of sleep
(disengaged from surroundings, breathing and heart rate are regular, and body temp drops)
N3 = deepest and most restorative sleep
(BP decreases, muscles relax, the blood supply to muscles increases, tissue growth and repair NRG restored)
N4 = REM
(NRG to brain and body, restores brain chemistry, solidify new memories, dreams)
114
Striated Muscle
Looks striped under a microscope
115
Myrofibril
Rod like structure that has parallel arrays of actin and myosin
116
Skeletal vs Cardiac vs Smooth muscle
Skeletal connect to skeleton
| Smooth found in walls of arteries, respiratory system, digestive system
117
Muscle Fiber (Cell)
Has several nuclei
| Made of microfibrils
118
Muscle Bundle
Group of muscle cells
119
Thin Filament
2 helically arranged actin filaments
120
Thick Filament
2 long polypeptide chains of myosin with globular head
121
Tropomyosin
Wraps around thin filament
| Blocks myosin from pulling actin
122
Troponin
Ca binds and causes movement of tropomyosin
123
Sacromere
Region between 2 Z discs
124
Z Disc
Protein backbones
125
A Band
Myosin and actin overlap, has H band in the middle
126
I Band
Only actin, Z band in the middle, shortens during contraction
127
Sliding Filament Model
Muscles change length and produce force by the sliding of actin filaments relative to myosin filaments
128
Cross Bridge Cycle
1. Myosin head binds ATP and detaches from actin
2. Myosin head catalyzes the hydrolysis of ATP and cocks the head back
3. The myosin head binds actin forms a cross-bridge
4. ADP is released and produces a power stroke , causes the muscle to contract
129
Motor Endplate
Where neurotransmitter binds with postsynaptic receptors on the muscle cell
130
T Tubule
Conducts depolarization into interior fiber
| Orange tube
131
Sarcoplasmic reticulum
Depolarization leads to release of Ca from sarcoplasmic reticulum
Blue wrap around muscle cell
132
Antagonist v Anonist Muscle
Pull in opposite directions
| Muscles that combine to produce smaller motion = agonist
133
Force Summation
2nd action potential arrives before muscle can relax → greater force produced
134
Tetanus Contraction
Muscle force reaches plateau and remains steady as stimulation continues
135
Motor Unit
Motor neuron and the muscle fibers it innervates
136
Phermone Prefixes
```
Endo = internal
Para = regional small distance
Auto = within a cell or adjacent cells
Exo = external
```
137
Hydrophilic hormones
Can’t cross bilayer
Activate signal transduction pathways
Quick response, short effect
Surface receptor → 2nd messenger pathway
138
Hydrophobic Hormones
Cross bilayer
Alter gene expression
Slow response, long effect
Receptor in cytoplasm or nucleus
139
hypothalamus
Send signals to pituitary gland
140
Neurosecretory cells
Releases hormones into bloodstream
141
releasing factor hormones
Stimulate anterior pit to release stimulating hormones
| Stimulating hormones cause release of other hormones
142
tropic vs. direct hormones
Tropic hormones control the release of other hormones
143
insulin
Hormone circulates the blood
144
Anterior pituitary
Neurosecretory cells release releasing factors in bloodstream → ant pit release hormones
145
posterior pituitary
Neuorsecorty cells extend axons into post pit → release hormones into the bloodstream
146
Glucagon
Hormone stimulates breakdown of glycogen into glucose and release from liver/muscle cells
147
corticotropin-releasing factor
Stimulates the release of larger amount of ACTH by ant pit
148
adrenocorticotropic hormone
Stimulates cells to secrete cortisol
149
Cortisol
Causes acute stress response
150
positive feedback
Accelerate the response of the target cell
| Stimulus causes response in same direction as the initial stimulus
151
oxytocin
Causes contraction during labor
152
Presynaptic Cell
Neuron sending the signal
153
Postsynaptic Cell
Information goes to another neuron
| Neuron receiving the information
154
Negative Feedback
A response (such as heat) opposes the stimulus (cold), leading to a stable state (a steady temperature).
155
Nucleus accumbens
Register motions to invoke experience
156
Type of muscle found in heart, limbs, and torso
Striated
157
Effect of ADP and Pi release from myosin
Power stroke (thin filament slides)
158
Type of contraction results in greatest force achieved by a muscle
Lengthening contraction
159
Characteristics of striated muscle cell
Mulitple nuclei
Hundreds of microfibrils
Mitochondria
Sarcoplasmic reticulum
160
Effect of ATP Hydrolysis
Cocking back of myosin head
161
Muscle protein types found in striated and smooth muscles
Actin & myosin
162
Force exerted by a muscle depends on
```
# of motor units activated
Frequency of stimulation
```
163
Autonomic nervous system
Sends nerve signals to smooth and cardiac muscles
164
Muscle Force Output
Depends on # of motor units activated in a given time frame
165
What causes muscle cell to fire Action Potential
Release of Ca2+ from Sarcoplasmic reticulum
166
Bulk Flow Example
Ventilation via trachea and circulation
167
Highest partial pressure of O2
Trachea / mouth
168
Lowest partial pressure of O2
Pulmonary artery
169
Nerve signals from the hypothalamus control hormone output of
Posterior pit gland
170
Smallest structure in the lung
Alveolus
171
Organ produces oxytocin and ADH
Posterior pit
172
Gas exchange
The transport of O2 and CO2 between an animal and its environment
173
bulk flow vs diffusion
Diffusion: the random movement of individual molecules
| Bulk Flow: physical movement of fluid over a given distance
174
ventilation
Bulk Flow
Movement of animal’s respiratory medium past a specialized respiratory surface'
Breathing moves air into the lungs and Carbon out of the lungs
175
circulation
Bulk Flow
Movement of a specialized body fluid that carries O2 and CO2
Oxygen and CO2 are transported by the circulatory system to and from cells
176
tidal ventilation
Inhalation and exhalation
177
intercostal muscles and diaphragm
Attached to adjacent pairs of ribs
| Assist diaphragm by elevating ribs on inhalation and depressing during exhalation
178
trachea
Central airway leading to lungs
179
Bronchi
Airway that supplies a lung
180
bronchiole
Carries air to alveoli
181
alveoli
Gas diffusion takes place
182
pulmonary capillaries
Small blood vessels
| Supply alveolar wall
183
Hemoglobin vs Myoglobin
Hemoglobin
Has 4 binding sites
Myoglobin
Has 1 binding site
184
Heme group (Fe)
Binds to oxygen
185
loading vs unloading
Areas with high PP of O2 → hemoglobin load up
| Areas with low PP of O2 → hemoglobin unloads
186
cooperative binding
Once one heme binds, the other 3 groups want O2 even more Conformation change in hemoglobin after each bind
187
allosteric inhibition via CO2 and H+
Biproducts of cellular respiration bind to heme groups and prevent binding of O2. Makes sure that O2 is available to cells that need it.
188
dissociation curve
pO2 vs % of O2 bound to hemoglobin
| Sigmodial in shape (in the middle small changes in pO2 0→ large change in saturation)
189
Artery
Large, high pressure vessels that move blood flow away from heart and to tissues
190
Arteriole
Blood vessles of progressibley smaller diameter
191
Vein
Large, low pressure vessels that return blood to the heart
192
Venule
Progressively larger diameter vessels
| Drain into a few larger veins that return blood to the heart
193
Capillary
Finely branched networks of very small blood vessels
194
Pressure v Resistance
Resistance determined by fluid’s stickiness and vessel’s length (radius)
Pressure required to overcome resistance
195
Blood Pressure v Osmotic Pressure
Arterial end: blood pressure = out, osmotic pressure = in (total = out)
Venous end: blood pressure = out, osmotic pressure = in (total = in)
196
Lymph
Fluid that enters the lymphatic system
197
Vasoconstriction v Vasodilation
Constriction: blood vessles constrict
Dilation: blood vessles relax (high blood pressure)
198
Pulmonary v Systematic Circulation
Pulmonary: to the lungs
Systematic: to the rest of the body
199
Systole v Diastole
Systole: Contraction of ventricles , pump blood out of the heart
Diastole: Relaxation of ventricles , fill ventricles with blood
200
Modified Muscle Fibers
Transmits action potentials
201
Essential Amino Acids
Can’t be synthesized by cellular pathways
202
Vitamins/Minerals
Elements other than CHON required in diet
| Organic molecules required in small amounts in diet
203
Foregut
Mouth, esophagus, stomach
| Digestion
204
Midgut
Small intestine
| Digestion and absorption takes place
205
Hindgut
Large intestine and rectum
| Absorption and elimation of waste
206
Mechanical v Chemical Digestion
Mechanical: break down, move along, mix up
Chemical: completed by enzymes and require high SA
207
Absorption
Breakdown products taken up into the bloodstream
208
Saliva
Makes food moist and easy to swallow ; has lipase
209
Amalyse
Breaks down carbs to begin digestion of sugars/starches
210
Peristalsis
Waves of smooth muscle contraction and relaxation (move food along)
211
Stomach
Protein and lipid breakdown
| Stores and digests foods
212
Pepsin
Breaks down protein into amino acids
213
Pepsinogen
Converted into pepsin with acid
It is secreted by the chief cells by the process of exocytosis
activated by either HCl or by pepsin already in the stomach and can begin to breakdown proteins via hydrolysis
214
Lipases
Break down lipids
215
Parietal Cell
Secretes HCL
216
Pyloric Sphincter
Opens and allows small amounts of digested food to enter small intestine
Regulates rate at which the stomach empties
217
Duodenum
Food enters from the stomach
218
Pancreas
Produces digestive enzymes
219
Gall Bladder
Bile stored
220
Bile
Breaks large clusters of fats into smaller lipid droplets
221
SEcretin
Released by cell lining in duodenum
| Stimulates pancreas to release bicarbonate ions to neutralize acid
222
Pancreatic Duct
Joins with common bile duct to make ampulla of vater
223
Villi / Microvilli
Highly folded inner surfaces in the small intestine
| Increase surface area for absorption of nutrients
224
Na-glucose transporter
Glucose enters the intestinal cell with Na driven by Na concentration difference
225
Glucose transport protein
Helps glucose exit the intestinal cell
226
Hepatic port system
Drains spleen, pancreas, gallbladder and GI tract to teh liver
227
Liver
Detox anything harmful, metabolizing energy, send sugar into circulation or store it
228
Large intestine
Water and mineral ions reabsorbed
| Retains digesta long enough to absorb water and nutrients before expulsion
229
Rectum
Stores waste products
230
Osmotic pressure
Pressure needed to prevent water from moving across a selectively permeable membrane
231
Osmoregulation
regulation of osmotic pressure or water content. It keeps internal fluids from becoming too concentrated (high osmotic pressure) or too dilute (low osmotic pressure).
232
Filtration
Blood is filtered through an extracellular space
| Allows some substances to pass through but retains others
233
Reabsorption
Essential molecules are transported back into the blood
Requires active transporters for some molecules
Water is reabsorbed into the cells by osmosis
234
Secretion
Active transport of molecules from the blood into the extracellular space
Adds solutes to filtrate
235
Nephron
Functional unit of the kidney
236
Renal cortex v renal medulla
Outer layer of medulla
| Middle of nephron
237
Glomerulus
Tufted loop of specialized capillaries
238
Bowman’s capsule
Sac that encases tufts of capillaries
239
Podocyte
Loosely interlock to create slits in cell layer
| Create filter that allows small molecules to pass through but blocks proteins/large cells
240
Proximal v distal convoluted tube
241
Loop of henle
Reabsorb water
| Makes the medulla salty
242
Collecting duct
Empty into renal pelvis and drinking through ureter
| Levels adjusted to meet osmoregulatory needs
243
Ureter
Brings urine from kidneys to bladder
244
ADH
Increases collecting duct permeability to water
245
AQP
Transmembrane protein
Impermeable to ion flow
Suck water from urine
Bio 151
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