Test 3 Flashcards
1
Q
Animal Cell Characteristics
A
- heterotrophs
- multicellular
- no cell wall
2
Q
When was the first evidence of animals? What was it?
A
- 700 mya
- first animal fossils were sponges
3
Q
What are sponges related to?
A
- choanoflagellates; are sessile (immobile) and filter feeders
4
Q
Major Animal Phyla
A
- Porifera
- Cnidaria
- Platyhelminthes
- Nematodes
- Mollusca
- Annelida
- Arthopoda
- Echinodermata
- Chordata
5
Q
2 General Trends in Animal Evolution
A
- increase in mobility
- increase in size
6
Q
What is required for Increase in Mobility
A
- requires:
a) tissue: muscles, nervous tissue
b) skeleton
c) orientation (having a front and a back end)
7
Q
What is the front end of an animal used for?
A
- sensory system
- feeding structures
8
Q
What is the rear end of an animal used for?
A
- locomotive structures
9
Q
What is required for Increase in Size
A
requires:
a) circulatory system
b) organs
10
Q
What is the circulatory system used for?
A
movement within the body
11
Q
What are organs used for?
A
they work together within the circulatory system
12
Q
Sessile definition
A
immobile
13
Q
5 Characteristics of the Animal Phyla
A
- symmetry
- level of organization
- gut development
- type of coelom
- segmentation
14
Q
What does symmetry help with? What are the three versions?
A
- helps with mobility and orientation
- 3 versions:
a) asymmetry
b) radial symmetry
c) bilateral symmetry
15
Q
Asymmetry
A
- porifera
- sponges are not mobile so they do not need symmetry
16
Q
Radial Symmetry
A
- more than 2 ways to divide the body and get mirrored halves
- cnidaria; good for up and downward movement
17
Q
Bilateral symmetry
A
- only one way to divide body in half and get mirrored halves
- all other phyla
18
Q
What are the 3 levels of organization?
A
- cellular level
- tissue level
- organ level
19
Q
Cellular Level
A
- body is composed of specialized, mostly totipotent cells that are capable of living on their own
- lack tissue, so cells work independently
- of cut in half, new organism forms
- porifera
20
Q
Tissue Level
A
- body composed of tissue and lacks organs
- cells work together
- cnidaria
21
Q
Organ Level
A
- body composed of organs
- all other phyla
22
Q
Tissue
A
group of similar cells that work together to perform a specific function within an organism
23
Q
Organ
A
group of tissue in an organism that has adapted to perform a specific function
24
Q
Blastula
A
- 64 cell stage
- totipotent
- if split, you get twins
- 2 things can happen:
a) can become ciliated
b) gastrulation
25
Blastocoel
fluid filled cavity in blastula
26
What happens if the blastula becomes ciliated?
- develops into a sponge (porifera phylum)
27
What happens if the blastula goes through gastrulation?
- develops into a gastrula
28
Gastrula
- differentiated
- 2 embryonic tissues:
a) ectoderm
b) endoderm
29
Ectoderm
- all cells on the outside of gastrula
- partially specialized tissue that becomes integument and/or the nervous system
30
Endoderm
- in the "dimple"/archenteron of the gastrula
- partially specialized tissue that becomes the lining of the digestive system
31
Archenteron
- embryonic gut
32
What are the two things that can happen to the gastrula?
1. archenteron expands and fills interior
2. third embryonic tissue forms
33
What happens when the archenteron expands and fills the gastrula interior?
- you get a gastrovascular cavity
34
Gastrovascular cavity
- body formed from 2 embryonic tissues
- diploblastic
- responsible for the digestion of food and transport of nutrients
- cnidaria
- tissue level of organization
35
What happens if a third embryonic tissue forms from the gastrula?
- you get a triploblastic cell
- creates the mesoderm
- organ level of organization
36
Mesoderm
- partially differentiated tissue that becomes muscle, skeletal system, circulatory system, and organs
37
Blastopore
- opening that forms during gastrulation
- later develops into mouth or anus
38
Gastrulation
- embryonic stage where the 3 germ layers (ectoderm, endoderm, and mesoderm) are established
39
Diploblastic
organism with 2 germ layers: ectoderm and endoderm
40
Triploblastic
organism with 3 germ layers: ectoderm, endoderm, mesoderm
41
Gut Development
- 2 aspects
a) completeness
b) orientation
42
Gut Development: Completeness
a) no gut: porifera
b) incomplete gut: one opening; cnidaria and platyhelminthes
c) complete gut: 2 openings; more efficient bc start and end; all other phyla
43
Gut Development: Orientation
- protostome
- deuterostome
44
Protostome
- blastopore becomes the mouth
- nematodes, mollusca, annelida, arthopode
45
Deuterostome
- blastopore becomes the anus
- echinodermata and chordata
46
Type of Coelom
- triploblasts
- 3 versions
a) acoelom
b) pseudocoelom
c) coelomate
47
Coelom
body cavity that houses organs
48
Acoelom
- coelom is filled with mesoderm that surrounds organs
- heavy and less flexible
-ex: tapeworms
- platyhelminthes
49
Pseudocoelom
- not completely lined by mesoderm
- organs move freely
- nematodes
50
Coelomate
- completely lined by mesoderm
- mesoderm and endoderm being close to each other allows for complex digestive systems
- mollusca, annelids, arthopoda, echinodermata, chordata
- organs are held in place
51
Segmentation
- body cavity is divided into discrete segments
- chordata, annelida, arthopoda
52
What is segmentation good for?
Segments have unique set of genes that are much different from each other that allow for complex bodies
53
What are the 4 major animal tissue types?
1. epithelial tissue
2. connective tissue
3. nervous tissue
4. muscle tissue
54
Epithelial Tissue
- covers the body surfaces
- not vascularized
- 3 shapes
- functions:
a) protection from predators, desiccation, bacteria, abrasion
b) thermal regulation
c) absorption
d) secretion
e) diffusive exchange
55
What are the 3 epithelial tissue shapes?
- squamous epithelia
- cuboidal epithelia
- columnar epithelia
56
What does it mean to be vascularized?
to have a blood supply
57
What are the 2 versions of Squamous Epithelia?
simple or stratified
58
Simple Squamous Epithelia
- flat cells
- barrier between 2 compartments
- one cell layer thick
- rapid movement of gas exchange
- derived from ectoderm
- in lungs and capillary blood cells
59
Stratified Squamous Epithelia
- multiple layers of flat cells
- basal layer is living
- outer layers are dead and full of keratin
- protection from abrasion
- skin, esophagus
60
What does keratin do within epithelial cells?
- makes cells waterproof
61
Cuboidal Epithelia
- secretory
- lines the glands
- derived from mesoderm
- in kidneys
62
Columnar Epithelia
- lining of the digestive system
- absorption/selective uptake of nutrients
- some secretion of digestive enzymes
- lifespan of 3 days
- from endoderm
63
Connective Tissue
- used for support, connections, and storage
- composed of cells in an extracellular matrix
- 5 types
64
What does extracellular matrix mean?
- ground substance and fibers that occupies the empty spaces between cells
- gel like
65
What are the 5 types of of connective tissue?
1. loose connective tissue
2. dense connective tissue
3. cartilage
4. bones
5. vascular
66
Loose connective tissue
- flexible
- well vascularized
- makes connections
- some storage
- 2 types
67
What are the 2 types of loose connective tissue?
areola and adipose
68
Areola tissue
- fibroblasts
- large cells with a matrix of ground substance and 2 protein fibers (collagen and elastin)
- holds skin intact
69
What does blasts mean, like in fibroblast?
blasts means to secrete
fibroblasts secrete fibers
70
Collagen
- high tensile strength
- prevents tissue from tearing
71
Elastin
- provides elasticity
72
Adipose tissue
- larger fibroblasts called adipocytes
- large vacuoles full of lipids
- few fibers
- fat tissue
73
Dense connective tissue
- few small fibroblasts
- little ground substance
- lots of collagen
- poorly vascularized
- 2 types
74
What are the 2 types of dense connective tissue?
- regular dense tissue
- irregular dense tissue
75
Regular Dense Tissue
- collagen fibers are parallel
- ligaments, tendons
- have to be strong
- similar to cables
76
What do ligaments do?
- connect bones across joints
77
What do tendons do?
- connects muscles to bones
78
Irregular dense tissue
- mesh of collagen fibers
- flexible but strong
- kidneys and dermis
79
Cartilage
- skeletal material used for flexible, structural support
- poorly vascularized
- composed of chondrocytes in a peptidoglycan matrix
80
Peptidoglycan matrix
- proteins and sugars
- collagen
- gel like
81
What are the cells of cartilage called?
- chondrocytes
82
Bones
- rigid skeletal material
- well vascularized
- composed of osteocytes in a calcium/phosphate matrix
- 2 types
83
How are bones arranged?
- in osteons
- tubular arrangements of osteocytes around a central canal
84
Calcium phosphate matric
- arranged in crystals
- not permeable
85
Central Canal
- contains blood vessels
86
Canaliculi
- channels that connect osteocytes to central canal
- allows for blow flow
87
Why can bones heal relatively quickly?
- because they have a good source of blood, energy, and nutrients
88
What are the 2 types of bones?
- cortical bone
- cancellous bone
89
Cortical bone
- where bone gets its strength
90
Cancellous bone
- stores marrow and provides horizontal support
91
What does bone marrow do?
produces blood cells
92
Bone growth: Length
- epiphyseal plate divides to produce osteocytes on shaft side
93
Epiphyseal plate
- layer of cartilage present during growth period that vanishes after puberty
- used for growth in length
94
Bone growth: girth
- osteoblasts and osteoclasts
95
Osteoblasts
- adds new bone to outside
96
Osteoclasts
- removes old bone from the inside
97
Stimulants and Inhibitors of Osteoblasts
Stimulants:
- stress/pressure on bones
- hormones (testosterone, estrogen)
- calcitonin
Inhibitors:
- parathyroid hormone
- age (40-45)
98
Calcitonin
- secreted in response to high Ca2+ levels in blood
99
Parathyroid hormone
- secreted in response to low Ca2+ levels in blood
100
Stimulants and Inhibitors of Osteoblasts
Inhibitors:
- stress/pressure on bones
- hormones (testosterone, estrogen)
- calcitonin
Stimulants:
- parathyroid hormone
- age (40-45)
101
What is bone strength a function of?
- function of thickness of cortical bone
- function of rates of osteoblasts and osteoclasts
102
Menopause vs bone growth
- menopause is a decline in estrogen
- women are more prone to weak bones at old age due to lack of estrogen
103
What can we control with bone growth and decline?
- our peak bone strength
- physical activity before and after peak
- our diet
104
Vascular Tissue
- blood
105
Nervous Tissue
- detects stimuli
- composed of neurons
106
What are the 3 types of neurons?
- sensory neurons
- interneurons
- motor neurons
107
Sensory neurons
- detects stimuli and signals central nervous system
108
Interneurons
- processes stimuli and triggers a response
109
Motor neuron
- sends signal to effector
110
What are the 3 transmembrane proteins in nervous tissue?
- potassium leak channel
- Na/K atpase
- Voltage gated sodium channel (VGNC)
111
K leak channel
- "always" open
- regulates resting potential
- allows potassium to flow across the membrane
112
Na/K atpase
- always working
- pumps 3 Na+ out of cell and 2 K+ into cell
113
Voltage Gated Sodium Channel (VGNC)
- when open, allows Na+ to cross membrane (in or out)
- when closed, membrane is at rest
114
Polarized membrane
a positive and negative charge on opposite sides of membrane
115
What are the two forces acting on potassium?
- diffusion (outward)
- electrical force (inward)
116
Resting Potential
- neuron at rest has a voltage gradient of -70 mv
117
What are the three VGNC configurations?
- closed
- open
- inactive
118
VGNC configuration: Closed
- when voltage gradient is < -40 mv
119
VGNC configuration: open
- brief configuration that occurs if voltage gradient is > -40 mv
- Na+ moves into cell
120
VGNC configuration: inactive
- brief configuration that occurs after the VGNC has been opened
- Na+ cannot cross and channel cannot be reopened
- refractory period
121
What is the VGNC mv threshold?
-40 mv
122
Action potential
- pulse of depolarization moving down a polarized membrane
123
Intensity of signal
- function of amount of action potentials send down a neuron
124
What are the 7 types of protein receptors?
- chemoreceptors
- mechanoreceptors
- photoreceptors
- proprioreceptors
- thermoreceptors
- electroreceptors
- magnoreceptors
125
Chemoreceptors
- detect chemicals
- responsible for taste and smell
126
Mechanoreceptors
- respond to pressure change
- responsible for touch and hearing
127
Photoreceptors
- responsible for vision
- detect certain lights
128
Proprioreceptors
- detect orientation of body
129
Thermoreceptors
- respond to change in temperature
130
Electroreceptors
- detect electrical current
131
Magnoreceptors
- detect magnetic fields
132
Two events that can start an action potential
1. sensory event
2. synapse
133
Sensory Event
- sensory neurons contain protein receptors on their dendrites that respond to specific stimuli by changing shape and allowing Na+ to cross the membrane
134
Synapse
- AP is passed from pre-synaptic neuron to post-synaptic neuron
135
Axon termination of presynaptic neuron/communication between neurons/synaptic event
1. AP reaches the axon termination of presynaptic neuron
2. causes VGCCs to open and Ca2+ flows into cell
3. causes exocytosis of neurotransmitter
4. neurotransmitters bind to receptor proteins on post-synaptic neuron
5. neurotransmitter receptor proteins change shape and creates a channel for Na+ to flow into cell and depolarizes the membrane (starts an AP)
6. Acetylcholinesterase removes acetylcholine from receptors and allows the post-synaptic neuron to re-polarize
136
What are the three types of muscle tissue?
Skeletal
Smooth
Cardiac
137
What is muscle tissue?
Contractile tissue
138
Skeletal Muscle
- composed of large, multinucleate, striated cells that are voluntary
- the more nuclei, the more proteins you can make in a short period of time
139
Smooth Muscles
- smaller, thinner, non-striated, uninucleate cells that are involuntary
140
Cardiac Muscle
- short, uninucleate, branched, striated cells
- connected through intercalated discs
141
Intercalated discs
- connects cardiac muscle
- composed of anchor and gap junction
142
What are the functions of anchor junctions in cardiac muscles?
- allows muscles to contract without tearing apart
143
What are the two types of skeletal muscle?
- slow twitch
- fast twitch
144
Slow Twitch
- well vasculated
- many mitochondria
- myoglobin
- stamina
- less contractile protein
- smaller
145
Fast Twitch
- less vascularized
- few mitochondria
- no myoglobin
- strength
- more contractile protein
- larger
146
What are the three important components of a skeletal muscle fiber?
1. sarcolemma
2. sarcoplasmic reticulum
3. myofibrils
147
Sarcolemma
- membrane
- polarized at rest
- can produce action potentials
- contains k leak channels, na/k atpase, and VGNCs
148
Sarcoplasmic reticulum
- folded membrane bound bag that stores Ca2+
- membrane is polarized at rest
- contains Ca2+ atpase and VGCCs
- pumps Ca2+ into SR
- can conduct action potentials
- connected to the sarcolemma through transverse tubules
149
Myofibrils
- bundles of contractile proteins that run the length of the cell
- arranged into sarcomeres
150
Sarcomere
contractile unit of myofibrils
151
Z line
Protein structure that connects two adjacent sarcomeres
152
What makes up the actin myofilament?
- actin
- tropomyosin
- troponin
153
What makes up a myofibril?
myosin myofilaments and actin myofilaments
154
At rest, why can't actin and the myosin head bind?
- tropomyosin is in the way because troponin is holding it in place
- muscle cannot contract
155
Simple Reflex Arc
1. sensory event partially depolarizes area around a VGNC, creating an action potential
2. the action potential moves down the polarized membrane, partially depolarizing other VGNCs along the way, while previous VGNCs become inactive and/or closed
this synaptic event occurs for sensory neuron to interneuron and interneuron to motor neuron (3-7):
3. action potential reaches the axon termination of interneuron neuron and causes VGCCs to open
4. Ca2+ flows into cell and causes exocytosis of neurotransmitters (acetylcholine)
5. neurotransmitters (acetylcholine) bind to neurotransmitter receptor proteins on post-synaptic neuron
6. receptor proteins change shape and creates a channel for Na+ to flow into cell, which depolarizes the membrane and starts an AP
7. acetylcholinesterase removes acetylcholine from receptors and allows the post-synaptic neuron to re-polarize
8. AP reaches axon termination of motor neuron and is sent to the muscle by a synaptic event through a neuromuscular junction. it spreads over the sarcolemma through transverse tubules over the sarcoplasmic reticulum membrane, VGCCs open, and calcium flows out to cytoplasm
9. calcium binds to troponin
10. troponin changes shape and pulls tropomyosin from the MH binding site
11. myosin head binds to actin (forms cross bridge)
12. power-stroke occurs (MH changes from obtuse to acute, pulls z lines closer together, causes sarcomere to short, and muscle contracts)
13. ATP binds to MH and breaks cross bridge
14. ATP is hydrolyzed
15. energy from the hydrolization of ATP is used to return MH heads to "rest" position (obtuse angle)
16. if calcium is still present in cytoplasm, another contraction cycle occurs.
156
Porifera
1. Asymmetrical
2. Cellular
3. No gut
4. Acoelomate
5. No segmentation
157
Cnidaria
1. Radial symmetry
2. Tissue
3. Incomplete gut
4. Acoelomate
5. No segmentation
158
Platyhelminthes (tapeworms/flatworms)
1. Bilateral symmetry
2. Organ
3. Incomplete gut
4. Acoelomate
5. Not segmented
159
Nematoda (roundworms)
1. Bilateral symmetry
2. Organ
3. Complete gut
4. Psueocoelom
5. No segmentation
160
Annelida (earthworms, segmented worms)
1. Bilateral symmetry
2. Organ
3. Complete gut
4. Coelomate
5. Segmented
161
Mollusca (snails, octopus)
1. Bilateral symmetry
2. Organ
3. Complete gut
4. Coelomate
5. No segmentation
162
Arthropoda (insects, crustaceans)
1. Bilateral symmetry
2. Organ
3. Complete gut
4. Coelomate
5. Segmented
163
Echinodermata (starfish)
1. Bilateral symmetry
2. Organ
3. Complete gut
4. Coelomate
5. No segmentation
164
Chordata
1. Bilateral symmetry
2. Organ
3. Complete gut
4. Coelomate
5. Segmented
165
What is the contraction cycle?
8. once the action potential reaches the muscle (the effector) it spreads over the sarcolemma through transverse tubules over the sarcoplasmic reticulum membrane, VGCCs open, and calcium flows out to cytoplasm
9. calcium binds to troponin
10. troponin changes shape and pulls tropomyosin from the MH binding site
11. myosin head binds to actin (forms cross bridge)
12. power-stroke occurs (MH changes from obtuse to acute, pulls z lines closer together, causes sarcomere to short, and muscle contracts)
13. ATP binds to MH and breaks cross bridge
14. ATP is hydrolyzed
15. energy from the hydrolization of ATP is used to return MH heads to "rest" position (obtuse angle)
166
Neuro muscular junction
synaptic connection between the axon termination of a motor nerve and a muscle
167
Affect of an AP moving across a muscle?
- rapid influx of calcium into cytoplasm
168
Do actin and myosin have a low or high affinity?
high
169
Myosin, troponin, actin, and tropomyosin are all ___?
proteins
170
What keeps calcium present in cytoplasm/VGCCs on SR open?
- constant APs sent down a neuron
- takes continuous APs to contract a muscle
171
Why is MH at a "rest" position?
- it takes energy to go from acute to obtuse, so obtuse position has more energy
172
What is a contraction?
movement of MH going from a high energy state to a low energy state, then using ATP to move from low energy state to high energy state
173
What is the purpose of troponin binding to Ca2+?
- to move tropomyosin off the MH binding site
174
What happens if you run out of ATP?
if due to extreme exercise:
- cross bridge can't break, so muscle cant relax = CRAMPING
if due to death:
- calcium gradually leaks out of SR membrane and triggers one incomplete contraction cycle
- body stiffens
= rigor mortis
175
Myoglobin
Protein that stores oxygen in slow twitch muscles
