joints and muscle tissue Flashcards
what kind of joint is the pubis symphysis
Cartilaginous joint
What type of joint is comprised mainly of dense connective tissue?
fibrous joints
What type of joint has limited movement and is comprised mostly of hyaline cartilage?
Cartilaginous joints
characteristics of fibrous joints
- dense connective tissue
- no movement
- in the cranium
characteristics of cartilaginous joints
- small amount of movement
- cartilage joins bones
characteristics of synovial joints
- most common joints in body
- six subtypes
- ample movement allowed
what is flexion
movement that decreases the joint angle between two body parts
what is dorsiflexion
raising the foot upward toward the shin.
what is pronation
a rotational movement of the forearm that results in the palm facing posteriorly
what is adduction
when a joint moves a part of the body toward the midline in one plane
what is plantarflexion
the movement of the foot in a downward motion away from the body
what is lateral rotation
the external rotation of the limb away from the midline
what is medial rotation
the internal rotation of the limb towards the midline
what is abduction
when a joint moves a part of the body away the midline in one plane
what is supination
the movement in which a person turns their hand, wrist, and forearm upward
what is extension
straightening a joint
what are diarthrotic joints
- freely moveable
- include all synovial joints of the body,
- found in the appendicular skeleton
- give the limbs a wide range of motion.
what are the synarthrotic joints
- immovable
- between the flat, plate-like bones of the skull
- provide for a strong union between the articulating bones
what are amphiarthrotic joints
- slightly movable
- cartilaginous joint that unites the bodies of adjacent vertebrae
what is pivot joint
a freely moveable joint (diarthrosis) that allows only rotary movement around a single axis
neck
what is condylar joint
move up and down, from side to side, and around in circumduction
- jaw, wrists, toes, and fingers
what is saddle joint
synovial joint that is composed of a concave bone and a convex bone.
what is hinge joint
a type of synovial joint that exists in the body and serves to allow motion primarily in one plane.
what is plane joint
formed between two bones in which the articular surfaces of the bones are flat
enabling the bones to slide over each other.
what is ball and socket joint
type of synovial joint that moves throughout three or more planes of motion into multiple directions.
The two types of myofilaments found in myofibrils are the thin filaments, composed primarily of the protein called __________, and the thick filaments, composed of __________.
actin
myosin
What is the A band?
The length of thick filaments
What is the I band?
The length with only thin filaments (no overlapping thick filaments)
What is the H zone?
The length with only thick filaments
when are the H zones and I bands are at maximum width
when the muscle is relaxed
what happens during contraction
the actin filaments are pulled toward the center of the sarcomere
what disappears when a muscle is fully contracted
H zone
What happens to the sacromere during contraction?
sarcomere shortens
What happens to the A band in a contracted muscle?
The A band does not change length
why doesn’t the A band change length?
the thick filaments have not changed their length
What happens to the I band in a contracted muscle?
The I band shortens
What happens to the H zone in a contracted muscle?
The H zone shortens.
An electrical impulse traveling along the sarcolemma and into transverse tubules causes calcium ions to diffuse from the __________ into the __________.
sarcoplasmic reticulum
sarcoplasm
What is the role of calcium in muscle contraction?
It binds to troponin, moving tropomyosin, so that myosin heads can bind to actin.
In order for muscle contraction to occur, cross-bridges form between what components of the muscle fiber?
Actin and myosin
what are possible outcomes of muscle contraction?
Movement of bones
Pumping of blood
Squeezing of intestinal contents
what is the layer of connective tissue that closely surrounds a skeletal muscle
epimysium
what is the perimysium
extends inward from the epimysium and separates the muscle tissue into small sections
connective tissue surrounds + separates fascicles
what are fascicles
- bundles of skeletal muscle fibers in epimysium muscle tissue
- a large bundle of muscle cells
whats the endomysium
a thin covering of connective tissue that holds fascicles of muscle fiber
separates muscle fibers
what is a tendon?
attached muscle to bone
what is fascia?
dense connective tissue that separates muscles
what is epimysium?
connective tissue at muscle surface
what’s a muscle fiber?
a muscle cell
what’s a myofibril?
threadlike bundles of myofilaments
what’s a (protein) filament?
thick and thin myofilaments
protein structure containing actin and myosin
what is a muscle?
an organ composed of different types of tissues
what is tropomyosin?
blocks binding sites for myosin
what are actin molecules?
individual proteins that assemble into chains
what is troponin?
binds calcium
what are myosin molecules?
many combine to form filaments
what are myosin heads?
form cross bridges
The striations seen in skeletal muscle consist of alternating dark bands, called the __________ bands, and light bands, called the __________ bands.
A
I
role of motor neuron axon
provides stimulation to muscle fiber
role of nucleus of muscle fiber
control centre for muscle fiber
what is the synapse
neuromuscular junction
what’s the synaptic cleft?
space between axon and muscle fiber
what is the motor end plate?
location of receptors for neurotransmitter
what is the myofibril?
bundle of thick and thin filaments
what is acetylcholine
a neurotransmitter that is released at neuromuscular junctions and that stimulates skeletal muscle to contract
