B3.3 HL only Flashcards
Sessile
the biological property of an animal describing its lack of a means of self-locomotion
Motile
the ability of an organism to move independently using metabolic energy
Venus flytrap
a small, perennial, carnivorous plant with leaves that snap shut to trap insects and spiders
action potential
a rapid sequence of changes in the voltage across a membrane
facilitated diffusion
a passive transport process that moves molecules across a cell membrane from an area of high concentration to an area of low concentration
water potential
a measure of water’s potential energy to move from one area to another
osmosis
the process by which water molecules move through a semipermeable membrane from a region of high water concentration to a region of low water concentration
Three-toed sloth
a mammal native to Central and South America that is known for its slow movement and arboreal lifestyle
Myofibrils
rod-like organelles in muscle cells that are responsible for muscle contraction
Sarcomeres
the basic contractile unit of muscle fiber. Each sarcomere is composed of two main protein filaments—actin and myosin—which are the active structures responsible for muscular contraction
Actin
a globular protein that plays a central role in cell movement, shape, and other cellular processes
Myosin
the prototype of a molecular motor—a protein that converts chemical energy in the form of ATP to mechanical energy, thus generating force and movement
Z-lines
a protein band that marks the boundary between adjacent sarcomeres in a striated muscle fiber
M-line
a vertical line in the center of a sarcomere that connects myosin filaments together
H zone
the central region of the A band in a sarcomere that contains only thick myosin filaments and no thin actin filaments
A band
a dark region within a sarcomere that contains thick myosin filaments and some thin actin filaments
I bands
the light bands in skeletal muscle cells that contain only actin filaments
Sliding filament theory
a widely accepted theory that explains how muscles contract by describing the movement of protein filaments within muscle fibers
antagonistic pair
a set of two muscles that work in opposition to each other, with one muscle contracting while the other relaxes
Myosin head
the part of a myosin molecule that binds to actin filaments and generates force to cause muscle contraction
Troponin
a protein found in muscle cells that regulates calcium and controls muscle contraction
Tropomyosin
a protein that regulates muscle contraction and is found in the actin filaments of muscles and non-muscle cells
Cross-bridge
the attachment of myosin to actin within a muscle cell, which occurs during muscle contraction
acetylcholine
a chemical messenger that transmits nerve impulses and plays a vital role in the body’s functions
neuromuscular junction
the point where a motor neuron meets a skeletal muscle fiber, and is responsible for triggering muscle contraction
power stroke
a structural change in a protein that occurs when a chemical change drives it
contraction
an increase in the tension or a decrease in the length of a muscle
Biceps
a large, thick muscle on the front of the upper arm that connects the shoulder to the elbow
triceps
a large, thick muscle at the back of the upper arm that extends the elbow joint and straightens the arm
Titin
a giant protein that plays a vital role in the structure, flexibility, and function of muscle cells
impulse
a signal that travels along a nerve fiber, transmitting information throughout the nervous system
motor neuron
a specialized nerve cell in the central nervous system (CNS) that transmits signals from the brain and sensory systems to muscles, glands, and organs, controlling voluntary and involuntary movements
neurotransmitter
a chemical messenger that carries signals from one nerve cell to another, or to a muscle cell or gland
Synapse
the junction between two neurons, or between a neuron and another cell, that allows nerve impulses to pass between them
Motor unit
a motor neuron and all the muscle fibers it controls
terminal bud
an undeveloped leafy offshoot located at the tip of a stem or twig where most of a plant’s growth occurs
pre-synaptic cell
a neuron that sends information to another neuron at a synapse
Voltage-gated Ca2+ channels
transmembrane proteins that allow calcium to enter cells in response to changes in the cell’s membrane potential
exocytosis
a biological process that moves large molecules and waste out of a cell and into the extracellular space
ligand-gated Na+ channels
transmembrane proteins that allow sodium ions to pass through a cell membrane in response to a chemical messenger, such as a neurotransmitter
Endoskeleton
a structural framework inside an animal that provides support and protection, and allows for movement
Exoskeleton
a hard, protective covering on the outside of an animal that supports its body and protects its internal organs, soft tissues, and fluids
levers
a rigid structure that uses a pivot point, or fulcrum, to create a turning motion
fulcrum
a fixed point, usually a joint, around which a lever rotates
Synovial joint
a freely movable joint in the body that allows for movement between long bones
Muscles
soft tissues that are made up of groups of cells that work together to perform a specific job, such as movement
Ligaments
bands of fibrous connective tissue that attach bones to bones and help stabilize joints and organs
Tendons
a fibrous connective tissue that attaches a muscle to a bone or other structure, such as the eyeball, and helps move it
Synovial fluid
a thick, viscous liquid that lubricates and protects the ends of bones in joints
Cartilage
a flexible, tough connective tissue that provides structure and support to the body, particularly in joints, the ears, and the nose
Ball-and-socket joint
a type of joint in which the rounded head of one bone fits into the cup-like depression of another bone, allowing for a wide range of movement
Femur
the thigh bone, the only bone in the upper leg that connects the hip and knee joints
Pelvis
the lower part of the trunk, located between the abdomen and the thighs
Joint capsule
a fibrous connective tissue that surrounds a joint, providing stability and allowing for movement
goniometer
a device that measures angles or rotates an object to a specific position
Hinge joints
a type of joint that allows for movement in one plane, usually only allowing for bending and straightening
Pivot joint
a type of joint in the human body that allows a body part to rotate around a single axis, similar to a wheel
Ventilation
the movement of air into and out of thelungsto supply oxygen to the body and remove carbon dioxide
intercostal muscles
muscles that are located between the ribs and are responsible for moving the chest wall and assisting with breathing
Inspiration
the process of breathing in, or taking air into the lungs
Expiration
the process of exhaling, or releasing air from the lungs
