Boot Camp Day 2.1 Flashcards
What is the movement in skeletal, cardiac, smooth muscle ?
- Skeletal muscle->moves the skeleton
- Cardiac muscle->moves blood
- Smooth muscle->moves “stuff” through hollow organs
What are the functions of muscle?
- Movement
- Posture (skeletal muscles)
- Joint Stabilization (skeletal muscles)
- Thermogenesis- heat generation
- Venous Return
- Energy source
- Glycemic control
- Control of openings and passageways
Thermogenesis:
* How does this happen?
Contracting skeletal muscles produce as much as 85% of our body heat
* Working out
* Shivering
What is the Venous Return for muscle
- Muscle pump action during dynamic exercise helps to pump/squeeze blood back to left ventricle
- This rhythmic pumping via contraction/relaxation increases venous blood return to the heart
Energy source of muscle?
Protein becomes an alternative source of energy during states of malnutrition or starvation
Glycemic control in muscle?
Muscles absorb and store glucose which helps regulate blood sugar concentration within normal range
Control of openings and passageways of muscle?
Sphincters: internal smooth muscle rings that control the movement of food, blood, and other materials within body
How are muscles classified?
Action: effect produced by a muscle to produce or prevent movement
What are the four functional groups of muscles?
What is the origin and insertion of muscles?
- Origin: Point of muscle attachment on the immovable or less movable bone (in limbs, the origin is usually proximal to the insertion)
- Insertion: Point of muscle attachment that moves toward the origin
What is the innervation of a muscle?
Why it is important to know the inn?
refers to the identity of the nerve that stimulates it
* Knowing innervation enables diagnosis of nerve, spinal cord, and brainstem injuries
from muscle tests
- Spinal nerves arise from where?
- Where do they emerge through?
- Immediated branch where?
- What do they innervate ?
- What is a plexus?
Spinal nerves arise from the spinal cord
– Emerge through intervertebral foramina
– Immediately branch into posterior and anterior rami
– Innervate muscles below the neck
– Plexus: web-like network of spinal nerves adjacent to the vertebral column
- Cranial nerves arise from where?
- Where do they emerge through?
- Inn what muscles?
- Numbered how?
Cranial nerves arise from the base of the brain
– Emerge through skull foramina
– Innervate the muscles of the head and neck
– Numbered CN I to CN XII
What is a motor unit?
a motor neuron and all the muscle fibers it innervates
The nerve muscle functional unit
What is the size principle?
Components of the NMJ:
* Axon terminal?
* Synaptic cleft?
* Motor End Plate?
- Tendon cont. into what?
- Why is CT imp?
- Tendon to fascia
- Imp to force transmission (relay muscles)
Sheaths of CT hold muscle fibers together in parallel alignment so they can work together. List them for the muscles
Epimysium
– encircles the entire muscle
– dense regular connective tissue
– lots of collagen (unidirectional)
Perimysium
– surrounds groups of 10-100+ muscle fibers into bundles called fascicles
– carries nerves, blood vessels, and stretch receptors
Endomysium-> cont with myocyte
– surrounds individual myocytes
– fine areolar connective tissue
What is the skeletal fiber structures?
What is the structure of a skeletal muscle fiber
What is the smallest contractile unit? Where is it located and composed of?
- Sarcomere
- Region of a myofibril between two Z discs
- Composed of thick (myosin) and thin (actin) myofilaments
how many actin encircle each myosin thick filament?
6
What are the myofilament proteins (proteins of the sarcomere)
- Actin (contractile function)
- Myosin (contractile function)
- Tropnin (regulatory function)
- Tropomyosin (regulatory function)
- Titan (structural function)
- Dystrophin (structural function)
- What are the thin and thick myofilaments
- What is a crossbrigde?
Give the 7 steps in the exitiation-contraction couping process
What is the cross bridge cycle?
What is the sliding filament theory?
- The cross-bridge cycle: Cycle of events that explains how a single myosin protein undergoes movement
- The sliding filament theory :Theory which explains how, by virtue of all mysoins undergoing the “cross-bridge cycle” the whole sarcomere can shorten in length
What happens when ca is present with muscles?
What are the subdivisions of the Nervous System?
What are the multipolar neuron and bipolar neuron?
- Multipolar neuron
– One axon and multiple dendrites
– Most common – most neurons in CNS - Bipolar neuron
– One axon and one dendrite
– Olfactory cells, retina, inner ear
What is a unipolar neuron and anaxonic neuron?
- Unipolar neuron
– Single process leading away from neurosoma
– Sensory cells from skin and organs to spinal cord - Anaxonic neuron
– Many dendrites but no axon
– Retina, brain, and adrenal gland
What are the four types of glia cells in the CNS and functions
What two neuroglia cells occur in the PNS and their functions
Schwann cells
* Envelope nerve fibers in PNS
* Wind repeatedly around a nerve fiber
* Produce a myelin sheath similar to the ones produced by oligodendrocytes in CNS
* Assist in regeneration of damaged fibers
Satellite cells
* Surround the neurosomas in ganglia of the PNS
* Provide electrical insulation around the neurosoma
* Regulate the chemical environment of the neurons
Speed of nerve impulse depends on two factors, what are they?
Diameter of fiber
* Larger fibers have more surface area and conduct signals more rapidly
Presence or absence of myelin
* Myelin further speeds signal conduction
What is the slowest to fastest nerve fibers?
i. Small, unmyelinated fibers: 0.5 to 2.0 m/s
ii. Small, myelinated fibers: 3 to 15.0 m/s
iii. Large, myelinated fibers: up to 120 m/s
Where are slow and fast signals sent to?
- Slow signals sent to the gastrointestinal tract where speed is less of an issue
- Fast signals sent to skeletal muscles where speed improves balance and coordinated body movement
What is a electrical potential?
A difference in concentration of charged particles between one point and another
- What are living vells and what do they have?
- Are cells more negative or positive on the inside?
- What is the resting membrane potential of neruons?
– Living cells are polarized and have a resting membrane potential
– Cells have more negative particles on inside of membrane than outside
– Neurons have about −70 mV resting membrane potential
What is a electrical current?
A flow of charged particles from one point to another
- In the body, currents are what?
- How are gated channels opened or closed?
- What does it enable?
- in the body, currents are mvt of ions, such as Na or K, through channels in the plasma membrane
- Gated channels are opened or closed by various stimuli
- Enables cell to turn electrical currents on and off
Why is the resting membrane potential present?
The resting membrane potential is due to a small buildup of negatively charged ions, mainly organic phosphates (PO43−) and proteins, in the cytosol just inside the membrane and an equal buildup of positively charged ions, mainly sodium ions (Na+), in the interstitial fluid just outside the membrane
What is the ionic basis of the resting membrane potential?
What are the change phases in the membrane potential?
The plasma membrane is _ at rest… what does that mean?
POLARIZED, there is a difference in potential across the membrane
How does excitation of a neuron happens by a chemical stimulis?
Ligands (chemicals that bind to a receptor) can bind and cause opening of certain ion channels in the plasma membrane. This allows ions to travel into (or out) of the cell, changing the membrane potential. This change is termed a local (or graded) potential.