biol114~ exam3

Joints

Joints

Points where bones meet and allow for movement.

Functional

Referring to the purpose or role of something.

Structural

Referring to the physical or anatomical characteristics of something.

Synarthrosis

Name for a joint with no movement.

Synostosis

Fusion of bones, such as at the front of the frontal bone.

Synchondrosis

A joint between bones where cartilage is present, such as between the first rib and sternum.

Suture

The fusion of skull bones with no movement.

Gomphosis

A joint where a tooth articulates with the mandible or maxilla.

Amphiarthrosis

A joint with a little bit of movement under certain conditions.

Symphysis

A joint between bones, such as the pubic symphysis, often associated with childbirth.

Syndesmosis

A joint between bones with a short ligament, such as the distal end of the tibia and fibula.

Diarthrosis

A joint with free movement.

Synovial

Joints that have synovial fluid, a synovial membrane, and a joint capsule.

Lubrication

The function of synovial joints to provide lubrication for smooth movement.

Shock Absorption

The function of synovial joints to absorb shock, often with the help of fat pads.

Nutrient Distribution

The function of synovial joints to distribute nutrients to the articular cartilage.

Protects Articular Cartilage

The function of synovial joints to protect the articular cartilage from damage.

Meniscus

Pads located between the femur and tibia in the knee joint, filled with synovial fluid.

Ligaments

Connective tissues that provide stability to joints, such as the ACL and PCL in the knee.

Bursa

Fluid-filled pockets that reduce friction between tendons and ligaments.

Fat Pads

Pads that provide shock absorption in joints, such as under the patella in the knee.

Plane Joint

Joints where bones glide over each other, usually flat, such as the tarsals.

Pivot Joint

Joints that allow for turning and rotating, such as between the atlas and axis vertebrae.

Saddle Joint

Joints that allow for side-to-side or tilting movements, such as the metacarpal of the thumb and trapezium.

Hinge Joint

Joints that function like a door, allowing for opening and closing movements, such as the elbows or knees.

Condylar Joint

Joints with rounded projections that allow for certain movements, including a little bit of gliding, such as the distal end of the radius.

Ball & Socket Joint

Joints with the greatest range of motion, such as the shoulders and hips.

Flexion

Decrease of an angle, such as bending the elbow.

Extension

Increase of an angle, such as straightening the knee.

Depression

Bringing something down, such as lowering the shoulders.

Elevation

Lifting something up, such as raising the shoulders.

Cardiac Muscle Tissue

Involuntary, striated muscle

Skeletal Muscle Tissue

Voluntary, striated muscle

Smooth Muscle Tissue

Involuntary, non-striated muscle

Tendon

Connective tissue that attaches muscle to bone.

Aponeurosis

Broad sheet of connective tissue that provides stability and connects muscles to bones. Ex- on frontal and occipital bone, and abdomen

Epimysium

Outermost connective tissue layer that surrounds a muscle.

Perimysium

Middle connective tissue layer that surrounds a fascicle (bundle of muscle fibers).

Endomysium

Innermost connective tissue layer that surrounds individual muscle fibers.

Sarcolemma

Plasma membrane of a muscle fiber.

Sarcoplasm

Cytoplasm of a muscle fiber.

Sarcomere

Contractile unit of a muscle fiber.

The Muscle

muscle as an organ → muscle fascicle → muscle fiber → myofibrils → myofilaments

Muscle Fibers (muscle cells)

Huge, many nuclei, sarcolemma, sarcoplasm.

T-tubule

Extends across the muscle fiber and surrounds each myofibril; opening at sarcolemma

Sarcoplasmic Reticulum

Membrane-bound structure that stores calcium ions.

Terminal Cisterna

End of the sarcoplasmic reticulum that stores the most calcium ions.

Triad

Terminal Cisterna → T-tubule → Terminal Cisterna

Myofilaments

Actin Proteins & Myosin Proteins

Thin Filaments

Actin proteins that make up part of the myofibrils.

Thick Filaments

Myosin proteins that make up part of the myofibrils.

G-actin

Active sites

F-actin

Twisted strands of G-actin to be functional

Tropomyosin

Covers active site

Troponin

Calcium receptor

Thin Filaments

G-actin, F-actin, Tropomyosin, Troponin

Myosin

Head & Tail

Titin

Molecular Spring

Needed for Contraction

Stimulation (nervous system), Calcium, and ATP

Thick Filaments

Contains Myosin & Titin

Resting Membrane Potential

Polarized state of a cell with a negative charge inside and a positive charge outside, maintained by the Na+/K+ pump, and found in Neurons & Skeletal muscle fibers.

Action Potential

Resting Potential → Depolarization (Na+ channels open with ACh neurotransmitters → Na+ enters cell → cell becomes positive) → Peak: Action Potential → Repolarization (AChE close the Na+ channels → K+ channels open → K+ exits cell → cell becomes negative) → Refractory Period →Resting Potential

Neuromuscular Junction

Connection between a motor neuron and a muscle fiber.

Axon terminals

Expanded end of axon

Motor End Plate

Neuron meets muscle fiber

ACh

Attaches to Na+ channel

AChE

Breaks down ACh; an enzyme

Isotonic

Muscle contraction where the length changes, either shortening (concentric) or elongating (eccentric).

Concentric

Shortening length

Eccentric

Elongating length

Isometric

Muscle length stays constant

ATP

Aerobic- Requires Oxygen

Glycolysis

Creates ATP; Anaerobic- Does NOT Require Oxygen

Sources of Stored Energy

ATP, Creatine Phosphate (C.P.), & Glycogen

Muscles At Rest

Use some remaining ATP to create Creatine P. and Glycogen

Active Muscles

Use ATP

Peak Activity Muscles

Use ATP from Glycogen

Oxygen Debt

Need extra oxygen during recovery period for ATP, it uses energy that doesn’t need oxygen to produce lactate. Glycolysis→ Converted by liver→ Lactate

Muscle Fatigue

Recovery tie depends on the amount of activity

High activity time

High recovery time

Low activity time

Low recovery time

Trophy

How something grows

Hypertrophy

Excessive muscle growth; muscles grew big

Atrophy

Absence of growth; muscles deteriorating away

Muscular Dystrophy

Muscle grows abnormally; genetic, sex recessive

Axial Muscles

Muscles that support and position the body.

Appendicular Muscles

Muscles that support and enable movement in the limbs.

Muscle Fiber Organization

The arrangement of muscle fibers within a muscle.

Circular-sphincters

Muscles that form a circular shape and act as sphincters, controlling the opening and closing of certain body parts.

Convergent

Broad muscle fibers that converge to a single attachment point.

Parallel

Muscle fibers that run parallel to the long axis of the muscle; less tension than pennate.

Pennate

Muscle fibers that are arranged at an angle to the long axis of the muscle, creating a feather-like appearance; more muscle fibers, more tension.

Origin

The proximal attachment point of a muscle.

Insertion

The distal attachment point of a muscle, which moves towards the origin during muscle contraction.

Action

The movement or action performed by a muscle.

Fulcrum

The joint around which movement occurs.

Load

The weight or resistance that the muscle must overcome.

AF/effort

The muscle contraction that generates the force to overcome the load.

First class

A type of lever system where the fulcrum is located in the middle, such as nodding the head.

Second class

A type of lever system where the load is located in the middle, such as going up on tiptoes.