Lecture 21 - Animal Movement 2

Question 1

Smooth muscle cells characteristics

Answer 1

unstriated, have no sarcomeres, single nucleus, unbranced, contraction is involuntary and controlled by autonomic motor neurons

Question 2

Where are smooth muscle cells located?

Answer 2

Lungs, blood vessels, digestive system, urinary bladder, reproductive system

Question 3

What is the function of acetylcholine in smooth muscles?

Answer 3

It stimulates the contraction of muscles in the stomach and intestine

Question 4

What is the function of epinephrine in smooth muscles?

Answer 4

It inhibits muscle contractions in the gut

Question 5

Cardiac muscle cells characteristics

Answer 5

Striated, contain sarcomeres, 1-2 nuclei, branched, contraction is involuntary with spontaneous depolarization, contain intercalated discs

Question 6

Function of intercalated discs

Answer 6

They form cytoplasmic connections between muscle cells, which allow electricity to flow between cells and coordinate the heart beat

Question 7

What is the function of acetylcholine in cardiac muscles?

Answer 7

Slow the heart rate

Question 8

What is the function of norepinephrine and epinephrine in cardiac muscles?

Answer 8

They speed up the heart rate

Question 9

Parasympathetic autonomic motor neurons

Answer 9

Release acetylcholine to both cardiac and smooth muscles

Question 10

Sympathetic autonomic motor neurons

Answer 10

Release norepinephrine and epinephrine to both cardiac and smooth muscles

Question 11

What do both sympathetic and parasympathetic autonomic motor neurons control?

Answer 11

Involuntary muscle contractions

Question 12

Skeletal muscle cells characteristics

Answer 12

Striated, thousands of sarcomeres, multinucleate, unbranched, activity is voluntary: requires signal from motor neuron

Question 13

How do skeletal muscle cells form?

Answer 13

By the fusion of embryonic cells

Question 14

Composition and location of skeletal muscle

Answer 14

40 to 45 percent of human body mass is skeletal muscle, skeletal muscle is attached to the skeleton

Question 15

Types of skeletal muscle

Answer 15

Fast muscle fibers, slow muscle fibers, intermediate muscle fibers. All types are found in all skeletal muscles but in different proportions

Question 16

Slow muscle fibers characteristics

Answer 16

Contract for a long time, fatigue very slowly, generate little force, red in color due to high myoglobin concentration, derive ATP via aerobic respiration, 30-32 ATP/glucose molecules, have many mitochondria

Question 17

Fast muscle fibers characteristics

Answer 17

Contact very rapidly, fatigue rapidly, generate lots of force, low myoglobin concentration, appear white, derive ATP via glycolysis, 3-5 ATP/glucose molecules

Question 18

Intermediate muscle fibers characteristics

Answer 18

Contract at a rate between slow and fast muscle fibers, fatigue at an intermediate rate, generate an intermediate amount of force, intermediate myoglobin levels, appear red or pink, derive ATP via aerobic respiration and glycolysis

Question 19

Sartorious muscle characteristics

Answer 19

Muscles of the thigh, small cross section (thickness) which leads to small amount of force, fibers are long which lead to a large change in length

Question 20

Gastrocnemius muscle characteristics

Answer 20

Muscles of the calves, large cross section (thickness) which leads to large amount of force, fibers are short which lead to a small change in length

Question 21

Skeletal systems function

Answer 21

Protection, maintenance of body posture, re-extension of shortened muscles, transfer of muscle forces to other parts of the body

Question 22

Types of skeletal systems

Answer 22

hydrostatic skeleton, endoskeleton, exoskeleton. Most animals have one or more of these skeletal systems

Question 23

Hydrostatic skeletons characteristics

Answer 23

When fluid is under compression, its pressure increases. Pressurized internal fluids can act as a skeleton. Example: hydrostatic skeleton of an earthworm

Question 24

Vertebrate endoskeleton

Answer 24

comprised of bones, cartilage, and ligaments. Bones articulate at the joints

Question 25

Bones

Answer 25

Cells in a hard extracellular matrix of calcium phosphate

Question 26

Cartillage

Answer 26

Cells scattered in a matrix of polysaccharides and protein fibers

Question 27

Cartilage function

Answer 27

Cushioning joints

Question 28

Ball and socket joint examples

Answer 28

Hip and shoulder joints

Question 29

Hinge joint examples

Answer 29

Elbow and knee joints

Question 30

Flexor muscles function

Answer 30

Pull bones closer together

Question 31

Extensor muscles function

Answer 31

Push bones further apart

Question 32

Relationship between flexor and extensor muscles

Answer 32

When a flexor contracts, an extensor extends, and vice versa

Question 33

Exoskeleton of arthropods characteristic

Answer 33

Are the key innovation of arthropoda, composed of chitin, and required the evolution of appendage joints. Muscles are located inside of the skeleton in arthropods. The muscles attach to apodemes.

Question 34

Apodemes

Answer 34

Ingrowths of the exoskeleton