Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Biology HL - IB > Muscle and motility > Flashcards

Muscle and motility Flashcards

(101 cards)

Start Studying
1
Q

What is the significance of movement in living organisms?

A

Movement is a universal feature of living organisms that allows them to find food, escape predators, reproduce, and adapt to changing environments. It plays a crucial role in survival and evolutionary success.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Define motile organisms and provide an example.

A

Motile organisms are those that can move independently and actively through their environment. An example is a fish, which uses fins to swim and navigate through water.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Define sessile organisms and provide an example.

A

Sessile organisms are those that remain fixed in one place and do not move actively. An example is a barnacle, which attaches itself to surfaces like rocks or ships and relies on water currents for feeding.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How do motile organisms adapt for movement?

A

Motile organisms have adaptations such as specialized limbs or fins for locomotion, flexible body structures for maneuverability, and sensory organs to navigate their environment effectively.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What adaptations do sessile organisms have for their lifestyle?

A

Sessile organisms often have adaptations such as strong attachment mechanisms (e.g., glue-like substances or hard shells) to anchor themselves, as well as structures like tentacles or filter-feeding systems to capture food from the surrounding environment.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Compare the energy expenditure of motile versus sessile organisms.

A

Motile organisms generally expend more energy for movement, requiring muscles and metabolic processes to facilitate locomotion. In contrast, sessile organisms have lower energy requirements since they do not actively move but rely on passive methods for feeding and reproduction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How does movement contribute to the survival of motile species?

A

Movement allows motile species to explore new habitats, search for food, avoid predators, find mates, and migrate in response to environmental changes, all of which enhance their chances of survival.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are some examples of environmental factors that influence movement in organisms?

A

Environmental factors influencing movement include:
- Availability of food sources
- Presence of predators
- Temperature and weather conditions
- Water currents (for aquatic organisms)
- Terrain type (land vs. water)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How does the concept of movement relate to evolution?

A

The ability to move has significant evolutionary implications; it can lead to diversification of species as they adapt to different environments. Movement-related adaptations can enhance reproductive success and survival, influencing natural selection.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Why is it important for students to explore both motile and sessile species?

A

Exploring both motile and sessile species helps students understand the diversity of life forms and their adaptations. It illustrates how different strategies for movement or lack thereof can be advantageous in various ecological niches.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the sliding filament model of muscle contraction?

A

The sliding filament model explains how muscle fibers contract through the sliding of actin and myosin filaments past each other within the sarcomere, leading to shortening of the muscle.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the key components of a sarcomere?

A

The key components of a sarcomere include:
- Actin filaments (thin filaments)
- Myosin filaments (thick filaments)
- Z-lines (boundaries of the sarcomere)
- M-line (center of the sarcomere)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How do actin and myosin interact during muscle contraction?

A

During muscle contraction, myosin heads attach to binding sites on actin filaments, forming cross-bridges. The myosin heads then pivot, pulling the actin filaments toward the center of the sarcomere, which shortens the muscle fiber.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What role does ATP play in muscle contraction?

A

TP provides the energy required for muscle contraction. It is necessary for:
- The detachment of myosin heads from actin after a power stroke
- The re-cocking of myosin heads to form new cross-bridges

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What initiates the process of muscle contraction at the molecular level?

A

Muscle contraction is initiated by an action potential from a motor neuron, which triggers the release of calcium ions from the sarcoplasmic reticulum. Calcium binds to troponin, causing a conformational change that exposes binding sites on actin.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How does calcium ion concentration affect muscle contraction?

A

Increased calcium ion concentration in the cytoplasm facilitates the binding of myosin to actin by moving tropomyosin away from binding sites on actin. When calcium levels drop, tropomyosin re-covers these sites, leading to muscle relaxation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Describe the power stroke in the sliding filament model.

A

The power stroke occurs when myosin heads pivot and pull actin filaments toward the center of the sarcomere after forming cross-bridges. This action shortens the sarcomere and generates force during contraction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What happens to the sarcomere during muscle contraction?

A

During muscle contraction, the sarcomere shortens as actin filaments slide over myosin filaments. The distance between Z-lines decreases, while the lengths of actin and myosin filaments remain unchanged.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How does repeated stimulation affect muscle contraction?

A

Repeated stimulation can lead to sustained contractions (tetanus) as calcium remains elevated in the cytoplasm, allowing for continuous cross-bridge cycling and force generation until fatigue occurs.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Why is understanding the sliding filament model important in physiology?

A

Understanding the sliding filament model is crucial for comprehending how muscles contract and produce movement. It also provides insights into various muscular diseases and conditions that affect muscle function and performance.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the role of the protein titin in muscle function?

A

Titin is a large protein that helps sarcomeres recoil after stretching and prevents overstretching. It provides structural support and elasticity, allowing muscles to return to their resting length after contraction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How does titin contribute to muscle elasticity?

A

Titin acts like a spring within the sarcomere. When a muscle is stretched, titin uncoils, storing elastic potential energy. Upon relaxation, it recoils, helping the muscle return to its original length.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are antagonistic muscles?

A

Antagonistic muscles are pairs of muscles that work against each other to facilitate movement. When one muscle contracts (the agonist), the other muscle (the antagonist) relaxes to allow for controlled movement.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Why are antagonistic muscle pairs important for movement?

A

Antagonistic muscle pairs are essential because muscle tissue can only exert force when it contracts. The coordinated action of opposing muscles allows for smooth and controlled movements in joints.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Give an example of an antagonistic muscle pair.
An example of an antagonistic muscle pair is the biceps brachii and triceps brachii in the upper arm. When the biceps contract to flex the elbow, the triceps relax; conversely, when the triceps contract to extend the elbow, the biceps relax.
26
How does titin prevent overstretching of muscles?
Titin provides passive tension when a muscle is stretched beyond its optimal length. This resistance helps prevent excessive elongation of the sarcomere and protects muscle fibers from damage during extreme stretches.
27
What happens to titin during muscle contraction and relaxation?
During contraction, titin becomes taut as it stores elastic energy. Upon relaxation, it helps pull the actin and myosin filaments back to their resting positions, aiding in the recovery of muscle length.
28
How do antagonistic muscles contribute to joint stability?
Antagonistic muscles contribute to joint stability by maintaining tension around joints. This balance between opposing forces helps prevent injury and allows for precise control during movement.
29
Why is understanding titin and antagonistic muscles important in physiology?
Understanding titin and antagonistic muscles is important because it provides insights into how muscles function during movement and recovery. It also helps explain mechanisms behind injuries, rehabilitation, and overall musculoskeletal health.
30
How do titin and antagonistic muscles work together during physical activity?
During physical activity, titin aids in maintaining muscle elasticity and preventing overstretching while antagonistic muscles coordinate movements by contracting and relaxing in opposition, ensuring efficient and controlled motion.
31
What is a motor unit in skeletal muscle?
A motor unit consists of a single motor neuron and all the skeletal muscle fibers it innervates. It is the basic functional unit of muscle contraction.
32
How does a motor neuron communicate with muscle fibers?
A motor neuron communicates with muscle fibers at the neuromuscular junction (NMJ), where it releases the neurotransmitter acetylcholine (ACh) to stimulate muscle contraction.
33
What are the main components of a neuromuscular junction?
The main components of a neuromuscular junction include: - Presynaptic terminal (axon terminal of the motor neuron) - Synaptic cleft (the gap between the neuron and muscle fiber) - Postsynaptic membrane (muscle fiber membrane with ACh receptors)
34
What happens at the neuromuscular junction during muscle contraction?
When an action potential reaches the presynaptic terminal, calcium ions enter, triggering the release of acetylcholine into the synaptic cleft. ACh binds to receptors on the muscle fiber, leading to depolarization and subsequent muscle contraction.
35
How does the structure of a motor unit affect its function?
The size of a motor unit varies; smaller units (e.g., eye muscles) allow for precise control of movement, while larger units (e.g., leg muscles) generate more force. All muscle fibers in a motor unit contract simultaneously when activated.
36
What role do synaptic vesicles play in neuromuscular transmission?
Synaptic vesicles in the presynaptic terminal store acetylcholine. Upon stimulation, they fuse with the membrane and release ACh into the synaptic cleft, facilitating communication between the motor neuron and muscle fiber.
37
What is the function of acetylcholine in muscle contraction?
Acetylcholine acts as a neurotransmitter that binds to receptors on the postsynaptic membrane of muscle fibers, initiating an action potential that leads to muscle contraction.
38
How does acetylcholinesterase contribute to neuromuscular function?
Acetylcholinesterase is an enzyme that breaks down acetylcholine in the synaptic cleft after it has activated receptors. This process prevents continuous stimulation of the muscle fiber, allowing for controlled contractions.
39
Why is understanding motor units important in physiology?
Understanding motor units is important because they are fundamental to how muscles contract and produce movement. Knowledge of their structure and function helps explain various muscular disorders and rehabilitation strategies.
40
How do multiple motor units work together during muscle activity?
Multiple motor units can be recruited simultaneously or sequentially to increase force production during activities. This recruitment allows for graded contractions, enabling fine control or powerful movements as needed.
41
What is the primary role of a skeleton in animals?
The primary role of a skeleton is to provide structural support and anchorage for muscles, facilitating movement by acting as a framework for muscle attachment and functioning as levers.
42
How do skeletons function as levers in movement?
Skeletons function as levers by providing rigid structures that muscles can pull against. When a muscle contracts, it exerts force on the skeleton, allowing for movement at joints, similar to how a lever amplifies force.
43
What are the two main types of skeletons found in animals?
The two main types of skeletons are: - Exoskeletons, found in arthropods (e.g., insects, crustaceans) - Endoskeletons, found in vertebrates (e.g., mammals, birds, reptiles)
44
Describe the structure and function of an exoskeleton.
An exoskeleton is a hard outer covering made of chitin in arthropods. It provides protection, support, and anchorage for muscles. However, it limits growth, requiring molting for size increases.
45
What are some advantages of having an exoskeleton?
Advantages of an exoskeleton include: - Protection from predators and environmental hazards - Support for muscle attachment - Prevention of water loss in terrestrial environments
46
Describe the structure and function of an endoskeleton.
An endoskeleton is an internal framework made of bone or cartilage in vertebrates. It provides support, protects vital organs, and serves as an anchor for muscles, allowing for greater flexibility and growth without molting.
47
What are some advantages of having an endoskeleton?
Advantages of an endoskeleton include: - Continuous growth without the need for molting - Greater range of motion due to flexible joints - Protection of internal organs while allowing for larger body sizes
48
How do muscles interact with the skeleton to produce movement?
Muscles contract to pull on bones at the joints. This interaction allows for various movements such as flexion, extension, rotation, and stabilization,
49
Why is it important to understand the roles of skeletons in movement?
Understanding the roles of skeletons in movement is important because it provides insights into biomechanics, evolutionary adaptations, and how different organisms have evolved unique structures to optimize mobility and survival.
50
How do arthropods and vertebrates demonstrate different adaptations related to their skeletons?
Arthropods demonstrate adaptations like jointed appendages and protective exoskeletons suited for their environment. Vertebrates have evolved endoskeletons that support larger body sizes and more complex movements, reflecting their diverse ecological niches.
51
What is the structure of a synovial joint?
A synovial joint consists of articulating bones covered with articular cartilage, a joint capsule enclosing the joint cavity, synovial fluid for lubrication, and ligaments that stabilize the joint.
52
How does the hip joint function as a synovial joint?
The hip joint is a ball-and-socket synovial joint formed by the head of the femur fitting into the acetabulum of the pelvis. This structure allows for a wide range of movements, including flexion, extension, abduction, adduction, and rotation.
53
What role does cartilage play in the hip joint?
Cartilage covers the surfaces of the femur and acetabulum, providing a smooth surface for movement, cushioning the joint during weight-bearing activities, and reducing friction between the bones.
54
What is synovial fluid, and what is its function?
Synovial fluid is a viscous fluid found in the joint cavity that lubricates the joint, reduces friction between articulating surfaces, nourishes cartilage, and absorbs shock during movement.
55
How do ligaments contribute to joint stability?
Ligaments are strong connective tissues that connect bone to bone around a joint. They stabilize the hip joint by restricting excessive movements and preventing dislocation during physical activity.
56
What are tendons, and how do they function in relation to muscles and bones?
Tendons are tough, inelastic connective tissues that attach muscles to bones. They transmit force from muscle contractions to bones, enabling movement at joints.
57
Describe the role of muscles in movement at the hip joint.
Muscles surrounding the hip joint contract to produce movement. When a muscle contracts, it pulls on its associated tendon, which then moves the femur within the acetabulum, facilitating various movements.
58
What types of movements can occur at the hip joint?
The hip joint allows for several types of movements including: - Flexion (bending) - Extension (straightening) - Abduction (moving away from midline) - Adduction (moving toward midline) - Internal rotation - External rotation
59
How does the structure of the hip joint enhance its stability?
The deep socket of the acetabulum provides a stable fit for the head of the femur. Additionally, ligaments and surrounding muscles contribute to stability while allowing for a wide range of motion.
60
Why is understanding synovial joints important in anatomy and physiology?
Understanding synovial joints is crucial because they enable complex movements essential for daily activities. Knowledge of their structure and function helps inform medical practices related to injuries and conditions affecting joints.
61
What is the range of motion (ROM) of a joint?
The range of motion (ROM) of a joint refers to the extent of movement possible at that joint, typically measured in degrees from the starting position to the end position of movement.
62
How is ROM typically measured?
ROM is typically measured using a goniometer, a device that consists of two arms—one stationary and one movable—that pivot around a central axis placed over the joint being measured.
63
What are the key steps in using a goniometer for measuring joint angles?
Key steps include: - Aligning the fulcrum of the goniometer with the joint center. - Positioning the stationary arm along a fixed body segment. - Moving the other arm along the moving body segment to measure the angle. - Reading the angle on the goniometer
64
65
Why is it important to stabilize the stationary portion of the body during ROM measurement?
Stabilizing the stationary portion helps isolate joint movement, ensuring that measurements reflect true joint motion without interference from movements of adjacent body parts.
66
What factors can affect the accuracy of ROM measurements?
Factors affecting accuracy include: - The presence of soft tissue around the joint - The skill and experience of the person measuring - The alignment and positioning of the goniometer - Joint swelling or injury
67
How can computer analysis be used in measuring joint angles?
Computer analysis can utilize digital imaging techniques to capture joint angles, providing precise measurements and reducing human error associated with manual goniometry.
68
What types of movements are assessed when measuring ROM?
Movements assessed during ROM measurement can include flexion, extension, abduction, adduction, internal rotation, and external rotation, depending on the specific joint being evaluated.
69
Why is understanding joint range of motion important in clinical practice?
Understanding joint range of motion is crucial for diagnosing musculoskeletal conditions, planning rehabilitation programs, monitoring recovery progress, and assessing functional mobility in patients.
70
How does ROM differ between various joints in the body?
ROM varies significantly between different joints; for example, the shoulder has a greater range of motion (ball-and-socket) compared to hinge joints like the elbow, which have more limited movement.
71
What are some common applications for measuring joint range of motion?
Common applications include: - Physical therapy assessments - Preoperative evaluations in orthopedic surgery - Monitoring progress in rehabilitation - Evaluating athletic performance and flexibility
72
What are the internal and external intercostal muscles?
The internal and external intercostal muscles are groups of muscles located between the ribs that play crucial roles in breathing by facilitating the movement of the ribcage during inhalation and exhalation.
73
How do the external intercostal muscles function during inhalation?
During inhalation, the external intercostal muscles contract, pulling the ribs upwards and outwards. This action expands the thoracic cavity, decreasing pressure in the lungs and allowing air to flow in.
74
What is the role of internal intercostal muscles during exhalation?
The internal intercostal muscles contract during forced exhalation, pulling the ribs downwards and inwards. This action reduces the volume of the thoracic cavity, increasing pressure in the lungs and expelling air.
75
How do the orientations of muscle fibers in internal and external intercostals contribute to their functions?
The fibers of external intercostal muscles run obliquely downwards and forwards, facilitating rib elevation. In contrast, internal intercostal fibers run obliquely downwards and backwards, aiding in rib depression, allowing for antagonistic actions during respiration.
76
What is antagonistic muscle action?
Antagonistic muscle action occurs when one muscle contracts while its opposing muscle relaxes. In the case of intercostal muscles, external intercostals contract during inhalation while internal intercostals relax, and vice versa during exhalation.
77
How does titin contribute to muscle function in intercostal muscles?
Titin is a protein that helps store potential energy in sarcomeres when one set of antagonistic muscles stretches while the other contracts. This elasticity aids in returning muscles to their original length after contraction.
78
Why is it important for intercostal muscles to work together?
The coordinated action of internal and external intercostal muscles is essential for efficient breathing. Their antagonistic relationship allows for controlled inhalation and exhalation, optimizing airflow into and out of the lungs.
79
What happens to the ribcage during deep breathing?
During deep breathing, both sets of intercostal muscles are actively engaged. External intercostals elevate the ribs while internal intercostals may assist with forced expiration, allowing for greater lung expansion and air intake.
80
How do external and internal intercostal muscles contribute to overall respiratory mechanics?
External intercostals assist with normal inhalation by expanding the thoracic cavity, while internal intercostals facilitate forced exhalation by compressing the thoracic cavity. Together, they enable effective ventilation during different breathing activities.
81
Why is understanding the function of intercostal muscles important in physiology?
Understanding the function of intercostal muscles is important because it provides insights into respiratory mechanics, assists in diagnosing respiratory conditions, and informs practices related to physical training and rehabilitation.
82
What is locomotion, and why is it important for living organisms?
Locomotion is the ability of an organism to move from one place to another. It is crucial for survival as it facilitates foraging for food, escaping predators, searching for mates, and migration.
83
How does locomotion aid in foraging for food? Provide an example.
Locomotion allows organisms to search for and access food resources. For example, birds fly to different locations to find seeds, insects, or fruits, optimizing their chances of obtaining nourishment.
84
Why is escaping from danger a reason for locomotion? Give an example.
Escaping from danger is essential for survival, as it helps organisms avoid predators. For instance, gazelles can quickly run away from predators like lions by using their speed and agility to evade capture.
85
How does locomotion facilitate the search for a mate? Provide an example.
Locomotion enables individuals to find and interact with potential mates, which is vital for reproduction. For example, male peacocks display their vibrant tail feathers and move around to attract females during the mating season.
86
What is migration, and why do organisms engage in this behavior?
Migration is the seasonal movement of animals from one region to another, often in search of better resources or breeding grounds. For example, monarch butterflies migrate thousands of miles from North America to Mexico to escape cold winters and find suitable habitats.
87
How does locomotion contribute to the survival of species?
Locomotion enhances species survival by enabling individuals to access food, avoid threats, reproduce successfully, and adapt to changing environments through migration or exploration of new habitats.
88
What role does locomotion play in the life cycle of aquatic animals?
Aquatic animals, such as salmon, use locomotion to migrate upstream to spawn. This movement ensures that they reach suitable breeding grounds with optimal conditions for laying eggs.
89
How does locomotion affect social behaviors in animals?
Locomotion allows animals to engage in social behaviors such as forming groups or herds. For example, wolves use coordinated movement during hunting and pack dynamics to improve their chances of capturing prey.
90
In what ways can locomotion be beneficial for plant reproduction?
While plants do not move actively like animals, some utilize wind or water currents (e.g., dandelion seeds) for dispersal. This form of passive locomotion helps ensure that offspring are spread over a wider area for better growth opportunities.
91
Why is understanding the reasons for locomotion important in ecology and biology?
Understanding the reasons for locomotion is important because it provides insights into animal behavior, ecological interactions, evolutionary adaptations, and conservation strategies necessary for protecting species and their habitats.
92
What are some key adaptations of marine mammals for swimming?
Marine mammals have several adaptations for swimming, including streamlined bodies, modified limbs that form flippers, a tail adapted into a fluke for propulsion, and specialized airways for efficient breathing during dives.
93
How does streamlining benefit marine mammals in water?
Streamlining reduces drag as marine mammals move through water. Their elongated, torpedo-shaped bodies allow for efficient movement, minimizing resistance and enabling faster swimming.
94
Describe the adaptation of limbs in marine mammals.
In marine mammals, forelimbs have evolved into flippers that provide stability and maneuverability in water. These flippers are wider and shorter than terrestrial limbs, allowing for effective propulsion and steering.
95
What is the function of the fluke in marine mammals?
The fluke is the horizontal tail fin of marine mammals that provides powerful propulsion. Its up-and-down movement generates thrust, allowing animals like whales and dolphins to swim efficiently.
96
How do the movements of the fluke differ from those of fish tails?
Unlike fish tails, which move side-to-side, the fluke of marine mammals moves up and down. This motion is more effective for generating thrust in a streamlined body shape.
97
What adaptations do marine mammals have for their airways?
Marine mammals possess adaptations such as flexible tracheas and specialized larynxes that allow them to close their airways while diving. This prevents water from entering their lungs during submersion.
98
How does periodic breathing benefit marine mammals?
Periodic breathing allows marine mammals to take in oxygen quickly before diving. They can hold their breath for extended periods while hunting or traveling underwater, optimizing their oxygen usage during dives.
99
What role does blubber play in swimming adaptations?
Blubber is a thick layer of fat under the skin that provides insulation against cold water, buoyancy to help with floating, and energy reserves during long periods without food or during migration.
100
How do sensory adaptations aid marine mammals in navigation and hunting?
Many marine mammals have developed acute hearing and echolocation abilities (e.g., dolphins) to navigate underwater and locate prey. These adaptations enhance their survival in aquatic environments.
101
Why is understanding the adaptations of marine mammals important in biology and conservation?
Understanding these adaptations is crucial for studying evolutionary processes, ecological roles within marine ecosystems, and informing conservation efforts to protect marine mammal populations from threats such as climate change and habitat loss.

Biology HL - IB (35 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions