16April - Muscles

Question 1

Protosomes

Answer 1

Ventral Nerve Cord

Include acoelomates, platyzoa, lophotrochozoa

Question 2

Deurterostomes

Answer 2

Dorsal nerve cord
Xenoturbellida
Echinodermata
hemichordata
Urochordata
Cephalochordata
Vertebrata

Question 3

Waggle Dance

Answer 3

Honey bees use waggle dance to send others to get food

Question 4

Vibrational Cue

Answer 4

Wolf and salticid spiders

Used in mating

Question 5

Steps of Response

Answer 5

1. Receptors sense stimuli
2. Sensory neurons transmit pinch message
3. Message is interpreted
4. Response is sent to motor neurons
5. Muscles are activated and you pull away

Question 6

Path of response signal

Answer 6

Touch
Nerves sense stimuli
Dendrites carry this down axon of sensory neurons

The process repeats in interneuron

Signal travels down ganglion
Ends at axon terminals of motor neurons

Question 7

Movement

Answer 7

Requires ATP
Can be aerobic - requires O2
Anaerobic - requires lactate dehydrogenase
More efficient O2 transport = faster response to the environment

Question 8

Ficks Law

Answer 8

Diffusion
ions move from high to low concentrations
To maximize diffusion:
-Increase concentration gradient
-Increase permeability of the membrane
-Increase charge gradient 

Electrical and chemical gradients can be used in conjunction to adjust flow rate

Inside of a cell is negative
Outside of a cell is positive

Question 9

Resting membrane Potential (RMP)

Answer 9

electrical gradient between a resting neuron and environment
Membranes and pumps keep ions from flowing with gradient so RMP is nonzero
RMP of NaK pump: -70mV

Question 10

Nerve Impulse Transmission

Answer 10

Outside of the cell is negative because:

• Na/K pump: 2K+ infor every 3 Na+ out
• Ion leakage channels: Let more K out than Na in

Question 11

Synapses

Answer 11

Presynaptic: transmitting signal
Synapse: gap that signal crosses
Post-synaptic: receive signal (neurons, muscles, endocrine glands)

Question 12

Ca and Neurotransmitters

Answer 12

1. Action potential arrives at axon terminal
2. Voltage gated Ca2+ channels open
3. Ca2+ enters cell
4. Ca signals to vesicles
5. Vesicles move to membrane
6. Docked vesicles release neurotransmitters
7. Neurotransmitters diffuse across synaptic cleft and bind to receptors

The diffusion distance is short to allow this to happen rapidly

To increase the rate of diffusion:

• increase conc of neurotransmitter
• increase surface are of postsynaptic cell
• decrease distance between pre and post synaptic cells

Question 13

What 3 ions are needed to cause a response?

Answer 13

Na+
K+
Ca++

Question 14

Skeletal Muscle Contraction

Answer 14

Sliding filament mechanism
Myofibrils contract
Myofilaments slide relative to each other
1.Tropomyosin: covers binding sites on actin
2. Troponin opens binding sites when enough Ca++ builds up
3. Myosin head binds to actin
4. Myosin pulls on actin filaments
5. ATP releases myosin head
6. ATP cleaves into ADP
7. ADP cocks myosin head to prepare for next stroke

Question 15

Skeletal Muscle

Answer 15

Actin: thin, twisted filaments
Myosin: thick filaments with hooks
Voluntary
Fast response
Moves the body - attaches to skeleton

Question 16

Other types of muscle

Answer 16

Smooth: auto, slow response, skin, respiratory, etc
Cardiac: auto, fast response, heart

Question 17

Types of skeletons

Answer 17

A. Hydro static - Worms, jellyfish
B. Exoskeleton - Insects
C. Endoskeleton - Vertebrates

Question 18

Hydrostatic Skeleton

Answer 18

Worms, jellyfish
Longitudinal and circular muscles
Fluid filled cavity
Flexible
Easily crushed

Question 19

Exoskeletons

Answer 19

Surrounds the body
Arthropods
Made of chitin
Protects internal organs
Strong but flexable at joints
Limits body size
Sometimes has to be shed to grow

Question 20

Endoskeletons

Answer 20

Bones inside
Attach to muscles
Bones and cartilage and can grow and change unlike chitin
Bones store nutrients
Continuous growth

Question 21

Phylum Annelida

Answer 21

Segmentation
Closed circulatory system
Neural connections between segments
Hydrostatic skeleton
Worms

Question 22

Phylum Arthropoda

Answer 22

Jointed appendages
Chitinous exoskeleton
Fusion of body segments
Open circulatory system
Respiratory system different from circulatory
Ventral nerve cord
Excretory systems
most insects

Question 23

Phylum Echinoderms

Answer 23

Deuterostomes form anus first?
Bilateral embryo
Penamerous radial adults
Water vascular system
Move via hollow tube feet inflated by ampulla
Starfish

Question 24

Phylum Chordata

Answer 24

deuterostome coelomates
fishes, amphibians, reptiles, birds, mammals
Somites: segmented blocks of muscles

Question 25

Vertebrates

Answer 25

1. Vertebral column replaces notochord
2. Cranium encases brain
3. Endoskeleton
4. Closed circulatory system

Question 26

Fishes

Answer 26

Vertebrates

Jaw grew from gill slits

Question 27

Ossification

Answer 27

Cartilage evolutionary replaced by bone

Question 28

Class Amphibia

Answer 28

First land vertebrates
Adaptations:
-Legs
-Lungs
-Larger muscles
-Water reproduction
-System to prevent desiccation

Features:

• Limbs
• Respiration
• Double loop blood circulation
• 4 chambered heart