12: How Do Animals Move? Flashcards
Module 3, Lesson 1
List the three types of skeletons.
- Hydrostatic skeleton
- Exoskeleton
- Endoskeleton
A(n) ____ is a fluid-filled cavity surrounded by muscles.
Hydrostatic skeleton
Soft-bodied terrestrial and aquatic vertebrates have…
Hydrostatic skeletons
A(n) ____ is a rigid outer covering that protects internal organs and offers an attachment site for muscles.
Exoskeleton
Arthropods have a(n)…
Exoskeleton
A(n) ____ is made up of a framework of rigid internal elements that offer attachment sites for muscles.
Endoskeleton
Echinoderms and vertebrates have a(n)….
Endoskeleton
List the two types of muscles used by an earthworm’s hydrostatic skeleton.
- Circular muscles
- Longitudinal muscles
In an earthworm, the ____ pressurize fluid when they contract.
Circular muscles
In an earthworm, the ____ cause chaetae to protrude and contact the ground when they contract.
Longitudinal muscles
____ are bristle-like external structures found in earthworms that contact the ground to hold the body in place.
Chaetae
Earthworms move using waves of ____ muscle contraction followed by waves of ____ muscle contraction.
Circular ; longitudinal
Arthropods’ exoskeletons are made of a polysaccharide called…
Chitin
True or false:
Chitin exoskeletons are stronger than bony endoskeletons.
False
A(n) ____ completely encases the muscles and internal organs, but limits the animal’s growth.
Exoskeleton
Because the exoskeleton limits the animal’s growth, it must be periodically shed and regrown in a process called….
Molting
A(n) ____ is a rigid internal skeleotn that forms the body’s framework.
Endoskeleton
In echinoderms, the endoskeleton is made of…
Calcite or calcium carbonate
In vertebrates, the endoskeleton is made of…
Bone and/or cartilage
Some large animals, such as sharks, have a primarily ____ endoskeleton.
Cartilage
In most vertebrates, the primary component of the endoskeleton is…
Bone
True or false:
Bone is stronger than cartilage but is less flexible.
True
Most of the cells involved in bone development are derived from undifferentiated ____ cells in embryonic tissue.
Mesenchyme
List the three basic types of cells involved in bone development.
- Fibroblasts
- Chondroblasts
- Osteoblasts
____ produce collagen.
Fibroblasts
____ produce cartilage and collagen.
Chondroblasts
Mature chondroblasts form….
Chondrocytes
____ produce bone.
Osteoblasts
Mature osteoblasts can form…
Osteocytes
____ are a cell involved in bone development that come from white blood cells instead of mesenchyme cells.
Osteoclasts
____ are involved in removal of bone.
Osteoclasts
____ is a specialized connective tissue that is tough but flexible and is found in many joints.
Cartilage
Cells in cartilage are surrounded by a(n) ____ which is secreted by chondrolasts.
Extracellular matrix
Cartilage cells that become stuck in cocoon-like spaces called ____ are called chondrocytes.
Lacunae
The matrix surrounding cartilage cells is composed of…
- Chondroitin
- Collagen fibers
Chondroitin is a glycoprotein-rich ground substance
Oxygen and nutrients reach ____ cells by diffusing from surrounding blood vessels.
Cartilage
True or false:
Cartilage contains blood vessels.
False
There are no blood vessels within the cartilage itself.
Cartilage heals very slowly because…
(two reasons)
- Aging chondroblasts divide slowly
- Cartilage is avascular
____ is a specialized connective tissue composed of both organic and inorganic components.
Bone
The matrix surrounding bone cells is composed of….
- Collagen fibers
- Polysaccharides
The majority of bone is made up of….
Inorganic hydroxyapatite
(mineral salts)
Osteoblasts in bone secrete an enzyme which causes ____ to form the crystalline hydroxyapatite.
Calcium phosphate
Bone’s flexibility and ability to stretch and twist comes from…
The extracellular matrix
Bone’s hardness comes from…
The inorganic hypoxyapatite
Most mammals have vascular ____ with internal blood vessels.
Bone
The ____ describes the internal organization of vascular bone.
Haversian system
____ are layers of bone laid down around Haversian canals.
Haversian lamellae
____ are narrow channels containing blood vessels and nerve fibers that run parallel to the length of the bone.
Haversian canals
List the three categories into which bone can be sorted based on density.
- Spongy bone
- Medullary bone
- Compact bone
____ is found at the apices of bones.
Spongy bone
____ is found inside the shaft of bones.
Medullary bone
____ is found in the perimeter of the shaft in bones.
Compact bone
Bone tissue develops from ____ and ____.
Fibrous tissue and cartilage
List the two types of bone development.
- Intramembranous
- Endochondral
____ development occurs between membranes and is typical of flat bones like the skull and sternum.
Intramembranous
____ development is the process by which bones are formed from cartilage.
Endochondral
During endochondral development, bones begin as…
Cartaliginous models
During endochondral development, calcified bone first replaces the ____ and then the ____.
Outer covering ; internal cartilage
Bone lengthening occurs at ____ located at the widened ends of the bones.
Epiphyseal growth plate
____ contain cartilage and young cells that undergo mitosis, thicken as they age, and eventually die.
Epiphyseal growth plates
Bones are lengthened by the ____ of cells in the epiphyseal growth plate.
Thickening
As bones get longer, the cartilage in them is simultaneously…
Calcified
True or false:
Bone growth in length stops during late adolescence, but growth in width can continue throughout life.
True
The process where osteoblasts constantly deposit new bone and osteoclasts constantly reabsorb old bone is called…
Bone remodeling
Bone remodeling is stimulated by….
(two)
- Mechanical stresses
- Regulatory hormones
When a bone bends, ____ are signaled to produce more matrix.
Osteoblasts
____ occurs when bone reabsorption outpaces bone deposit, causing bones to become extremely fragile.
Osteoporosis
All joints in the body are powered by….
Muscles
List the four types of joints.
- Ball-and-socket
- Hinge
- Gliding
- Combination
____ joints are located in the hips and shoulders and allow the greatest range of movement.
Ball-and-socket
____ joints are found in the knees, elbows, and fingers and allow forward and backward movement.
Hinge
____ joints are found between vertebrae and allow sliding movement from one surface to another.
Gliding
____ are found in the jaw and allow both rotation and side-to-side movement.
Combination
Muscles may attach directly to the bone, or they may be attached to the bone by…
Tendons
One of a muscle’s attachments to a bone, the ____, remains stable during movement.
Origin
One of a muscle’s attachment to the bone, the ____, is attached to the portion of the bone that moves.
Insertion
True or false:
Generally, movement caused by one muscle can be reversed by another muscle.
True
A muscle capable of reversing movement caused by another muscle is called a(n)…
Antagonistic muscle
Flexor and extensor of the leg are an example of movements caused by…
Antagonistic muscles
List the three main types of muscles.
- Smooth
- Skeletal
- Cardiac
____ muscles are found in internal organs and are under involuntary control.
Smooth
____ muscles tend to contract and relax very slowly.
Smooth
____ muscles are found only in the walls of the heart and are under involuntary control.
Cardiac
____ muscles are made up of a network of fibers connected by intercalated discs, which allow the fibers to contract as a unit.
Cardiac
True or false:
Cardiac muscles are self-exciting, meaning that the heart directs its own beating.
True
True or false:
Skeletal muscle cells have one nucleus.
False
They are multinucleated
Each ____ muscle consists of bundles of long muscle fibers (muscle cells).
Skeletal
Individual skeletal muscle fibers each contain a bundle of 4-20….
Myofibrils
Myofibrils are composed of a mixture of thick and thin…
Myofilaments
____ account for contraction of skeletal muscles.
Myofibrils
Under a microscope, myofibrils appear to have alternating….
Light and dark bands
The dark bands, called ____, in myofibrils are produced by a stack of thick and thin microfilaments.
A bands
A region of a myofibril where only thick filaments are visible is called a…
H band
Light bands in myofibrils, called ____, are formed by thin filaments.
I bands
Each I band is divided in half by a disc of proteins called the…
Z line
The smallest unit of muscle contraction, which repeats itself from Z line to Z line, is called a…
Sarcomere
During muscle contraction, the sarcomere…
Shortens
In a contracted sarcomere, there is a greater overlap of thick and thin filaments, causing the ____ to narrow significantly.
I and H bands
____ are motor proteins that convert chemical energy in ATP into mechanical energy.
Myosin proteins
List the major steps in the cross-bridge cycle.
(four)
- Hydrolysis of ATP causes the myosin head to move into an energized state
- The energized myosin head forms a cross-bridge with actin filaments
- ADP and Pi are released, shifting the myosin head into a low-energy state
- ATP binds to the myosin head to break the cross-bridge
The cross-bridge cycle continues as long as…
The muscle is stimulated to contract
True or false:
Breaking the cross-bridge requires an energy input.
True
When muscles are in a relaxes state, the myosin heads….
Are in an energized state but do not form cross-bridges
When a muscle is relaxed, myosin’s attachment site on actin is blocked by…
Tropomyosin
When a muscle is stimulated to contract, calcium ions enter the cytoplasm and bind to…
Troponin
The binding of calcium to troponin causes…
Tropomyosin to move and expose the actin binding sites
After contraction, in order for muscle cells to relax, calcium must be…
Pumped out of the muscle cells
Muscle cells store calcium ions in a modified endoplasmic reticulum called the…
Sarcoplasmic reticulum
How does a motor neuron releasing a neurotransmitter trigger the release of calcium ions?
(three)
- The muscle cell is depolarized by the neuron
- The depolarization travels deep into the cell via transverse tubules
- When the depolarization reaches the sarcoplasmic reticulum, Ca ions are released
____ are invaginations of the cell membrane that carry depolarizations deep into the cell.
Transverse tubules
The neurotransmitter released at the neuromuscular junction is…
Acetylcholine
Somatic motor neurons have branched ____ which enable them to form synapses with many different muscle cells.
Axons
A ____ is a set of muscle cells innervated by a single branched axon.
Motor unit
True or false:
When stimulated, all muscle fibers in a motor unit contract simultaneously.
True
Precise muscle actions have ____ motor units compared to larger muscle actions.
Fewer
A ____ is the response of a motor unit to a single action potential.
Twitch
During a ____, muscle fibers contract and then quickly relax.
Twitch
____ occurs when multiple stimuli are applied to a motor unit before it can relax.
Summation
During ____, or normal muscle contraction, muscle contraction is sustained but shaky.
Incomplete tetanus
Smooth and sustained muscle contraction is called…
Tetanus
____ occurs when a high frequency of stimulation causes maximum muscle tension and a plateau in muscle contraction.
Complete tetanus
____ fibers are responsible for rapid generation of power.
Fast twitch
____ fibers contract rapidly and tire quickly.
Fast twitch
Some ____ fibers can respire anaerobically using glycogen stores.
Fast twitch
____ require fewer capillaries, fewer mitochondria, and less myoglobin.
Fast twitch fibers
____ is a pigment that improves delivery of oxygen to muscle fibers.
Myoglobin
____ fibers often appear white in color.
Fast twitch
____ fibers rely on aerobic respiration for sustained action and endurance.
Slow twitch
____ fibers require more capillaries, more mitochondria, and more myoglobin.
Slow twitch
The additional capillaries and myoglobin found in slow twitch fibers make them appear…
Darker/reddish
