Physiology Flashcards
What are the three types of muscle in the body?
Skeletal
Cardiac
smooth
What produces the light and dark striations in skeletal and cardiac muscle?
Myosin produces dark
Actin produces light bands
What is a motor unit?
A single alpha motor neuron and all the skeletal muscle fibres it innervates
From big to small what are the names of the muscles?
Whole muscle
Muscle fibre
Myofibirl
Sarcomere
Myocin
Actin
What is the nerurotransmitter at the neuromuscular junction
Acetlycholine
How is an action potential stimulated in skeletal muscle?
Action potential spreades down T-tubules triggering calcium ion release from the lateral sacs of the sarcoplasmic reticulum
What is the functional unit of a muscle called?
A Sarcomere
What is a functional unit ?
The smallest component of an organ which is capable of performing all the functions of that organ
What are the 4 sarcomere zones
IAHM
What is the I zone?
Actin filamints that don’t overlap with myosin
What is the A band?
Area where Actin and Myosin filaments overlap
What is the H zone?
Lighter area in the middle where actin filaments dont reach
What is the m line?
Vertical band straight down the middle of the A and H zones
What is responsible for muscle tensions
Actin filaments sliding on myocin filaments
For what is ATP needed for in muscles?
During muscle contraction to power contraction
During relaxation to release cross bridges
and to pump calcium back into the sarcoplasmic reticulum
How does the skeletal muscle twitch compare to the action potential?
The action potential is much shorter so you can fire a bunch of action potentials in order to produce a stronger twitch
What cant Cardiac muscle be tetanised?
Because of the refractory period
What are the three metabolic pathwapys that supply ATP in muscle fibres?
Transfer of high energy phosphate from creatine phosphate to ADP
Oxidative phosphorylation
Glycolysis
What is the main source of ATP when O2 is present?
Oxidative phosphorylation
What is the main source of ATP when O2 is not present ?
Glycolysis
What are the three types of skeletal muscle fibres?
Slow-oxidative
Fast-oxidative
Fast-glycolytic
What spinal segment and peripheral nerve is tested during the knee jerk?
L3 and L4
Femoral Nerve
What are muscle spindles?
Intrafusal fibres with annulospiral fibres which sense when the muscle is stretched
What are the three types of joints?
Synovial
Fibrous
Cartilaginous
What do all synovial joints have which cartilaginous joints dont?
A synovial membane
What does the synovial fluid do for the chondrocytes?
Supply it with oxygen and nutrients
What gives synovial fluid its high viscosity?
hyaluronic acid
What type of cartilage makes up most of the articular cartilage?
Hyaline
Where does articular cartilage get its nutrients from?
Recives nutrients from synovial fluid
It has no blood supply of its own.
What is special about the nucleus of skeletal muscle cells?
They have loads of nuclei per cell
What are muscle bundles called?
Fasicles
What are the layers of connective tissue which organises muscles?
Epimysium
Perimysium
Endomysium
What do you call cells found in the cartilage?
Chondrocytes
Where do chondrocytes live?
Lacuna
What do chondrocytes do?
Secrete and maintain the extracellular matrix around them
What makes up the extracellular matrix in hyaline cartilage
75% water
25% Organic material of which 60% is type II collagena nd 40% is proteoglycan aggregates
What does Hyaline cartilage look like?
Blue-white and translucent
What does Elastic cartilage look like?
light yellow
What are the three types of cartilage?
Hyaline cartilage
Elastic cartilage
Fibrocartilage
What is bone made up off?
Mostly minerals, collagen and water
What are the two types of bone you would find in a long bone?
Solid Cortical Bone
Spongy Cancellous or trabecular bone
What are cement lines?
Lines found in osteons that have formed during remodelling
What does Cortical bone have that Trabeculae/Cancellous bone does not?
Cancellous/Trabecular bone does not have haversion cannals
What is located on bone surfaces and acts as a reserve pool of osteoblasts?
Osteoprogenitor cells
What are Osteoblasts?
Bone Builders
B for builders
What is an osteocyte?
A bone cell trapped within the bone matrix
What do osteoclasts do?
Found on the surface of the bone, they are responsilbe for bone resorption.
C for Cutters
How is mineral bone made ?
Osteoblasts secrete Osteoid which crystalises
What is the main mineral in bone?
Calcium Phosphate crystals
whats going on here?
Lamellar bone and woven bone undergoing remodelling
