Chapter 1 Flashcards
Axial Skeleton (4)
skull (cranium)
vertebral column ( C1 thru coccyx
ribs
sternum
Apendicular Skeleton (4)
- shoulder ( or pectoral) girdle (L and R scapula and clavicle)
- bones of the arms wrists, and hands (L and R humerus, radius, ulna, carpels, metacarpals, and phalanges)
- pelvic girdle (L and R coxal or innominate bones)
- bone of the legs, ankles, and feet (L and R femur, patella, tibia, fibula, tarsals, metatarsals, and phalanges
Joints
Junctions of bones
Fibrous Joints
allow virtually no movement
e.g sutures of the skull
Cartilaginous Joints
allow limited movement
e.g. intervertebral disks
Synovial Joints
allow considerable movement
e.g. elbows and knees
most sport and exercise movements occur at these joints b/c of low friction and large range of motion.
Articulating bone ends are covered with smooth _____ _______? The entire joint is enclosed in a capsule filled with ______ ______?
Hyaline cartilage.
Synovial Fluid.
Virtually all joint movement consists of rotation about _____ or ______?
point; axes
Depending on the number of directions about which rotation occurs, how are joints categorized?
Uniaxial Joints
Biaxial Joints
Multiaxial Joints
Uniaxial Joints
operate as hinge, essentially rotating about only one axis e.g. elbow and knee
Biaxial Joints
allow movement about two perpendicular axes
e.g. ankle and wrist
Multiaxial Joints
allow movement about all three perpendicular axes that define space
e.g. shoulder and hip ball-and-socket joints
Vertebral Column and it’s components
made up of vertebral bones separated by flexible disks that allow movement to occur.
7 cervical vertebrae ( neck)
12 thoracic vertebrae (upper-middle back)
5 lumbar vertebrae (middle-low back)
5 sacral vertebrae (rear part of pelvis)
3-5 coccygeal vertebrae (vestigial internal tail extending downward from pelvis
Epimysium
connective, fibrous tissue sheath surrounding skeletal muscle. Contiguous with the tendons at the ends of the muscle.
Tendon
attached to bone perioteum
Bone Periosteum
specialized connective tissue covering all bones; muscle contractions pull on tendon and, in turn, the bone.
Proximal
closest to trunk
Distal
farther from trunk
Superior
closer to head
Inferior
closer to feet
Muscle fibers
aka muscle cells; long, cylindrical cells 50-100 micrometers in diameter. Have nuclei situated on outer portion of cell. Striated appearance.
Fasciculi
under epimysium; bundles of muscle fibers (up to 150 fibers). Bundles surrounded by perimysium.
Perimysium
connective tissue surround fasciculi.
Endomysium
surrounds each muscle fiber; encircled by sarcolemma
Sarcolemma
fibrous membrane surrounding endomysium
Motor Neuron
nerve cell
Neuromuscular junction
junction between motor neuron and muscle fiber; aka motor end plate
Motor unit
motor neuron and the muscle fiber it innervates; all muscle fibers of a motor unit contract together when they are stimulated by the motor neuron.
Sarcoplasm
the cytoplasm of a muscle fiber; contains contractile components consisting pf protein filaments, other proteins, stored glycogen and fat particles, enzymes, and specialized organelles (mitochondria, and sarcoplasmic reticulum).
Myofibrils
dominate sarcoplasm; contain the apparatus that contracts the muscle cells, which consists primarily of 2 types of myofilaments: myosin and actin.
Myofilaments (2)
myosin and actin
-contains up to 200 myosin molecules
Myosin
consists of a globular head, a hinge point, and a fibrous tail.
-adjacent myosin filaments anchor to each other at the M-bridge in the center of the sacromere (H-zone)
Cross-brdiges
when the globular head of the myosin protrude away from myosin and pairs with actin.
Actin
consist of two stands arranged in a double helix.
-aligned at both ends of the sacromere and are anchored at the Z-line.
Sarcromere
smallest contractile unit of the skeletal muscle.
-structured having myosin and actin organized longitudinally.
A-band
DARK portion of sacromere.
-corresponds with the alignment of the myosin filaments.
I-band
LIGHT portion of sacromere.
- corresponds with the areas in two adjacent sacromeres that contain only action.
- shorten during muscle contraction as z-lines are pulled toward center of sacromere
Z-line
middle of the I-band and appears as a thin, dark line running longitudinally through the I-band.
-shorten during muscle contraction
H-zone
center of the sacromere where only myosin are present
-shorten during muscle contraction bc actin slides over myosin toward center of sacromere.
Sarcoplasmic Reticulum
parallel to and surrounding each myofibril; asystem of tubules, which terminates as vesicles in the vicinity of the Z-lines.
-these vesicles store Ca+ ions, which control muscle contraction
T-tubules
transverse tubules; run perpendicular to the sarcoplasmic reticulum and terminate in the vicinity of the Z-line between two vesicles.
-discharge action potential
Action Potential
discharged electrical nerve impulse from a motor nerve signals the release of Ca+ from the sarcoplasmic reticulum into myofibril, causing tension development in muscle.
Sliding-filament Theory
states that actin filaments at each end of the sarcomere slide inward on myosin filaments, pulling the Z-lines toward center of sarcomere and thus shortening the muscle fiber.
Troponin
protein situated at regular intervals along the actin filament and has high affinity for Ca+ ions.
-when SR is stimulated to release Ca+, Ca+ binds w/ troponin.
Tropomyosin
protein that shifts as a result of troponin binding w/ Ca+.
-runs along the length of the actin filament in the groove of the double helix.
Power Stroke
energy for pulling action of the muscle (contraction)
-comes from hydrolysis (breakdown) of ATP to ADP
ATP to ADP
catalyzed by the enzyme myosin adenosine triphosphatase (ATPase).
Acetylcholine
diffuses across NMJ as a result of AP arriving at nerve terminal, causing excitation of the sarcolemma.
All-of-nothing principle
a stronger AP cannot produce a stronger contraction.
Twitch
brief muscle contraction
Tetanus
stimuli delivered at so high a frequency that the twitches begin to merge and eventually completely fuse.
-this is the maximal amount of force the motor unit can develop.
Slow-twitch muscle fibers
develop force and relax slowly and have a long twitch time
Fast-twitch muscle fibers
develops force and also relaxes rapidly and have short twitch time
Type I
slow-twitch muscle fibers
-efficient, fatigue resistant, high capacity for aerobic energy supply, but have limited potential for rapid force development (low myosin ATPase activity and low anaerobic power)
Type II
inefficient, fatigable, low aerobic power, rapid force development, high myosin ATPase activity, and high anaerobic power.
Type IIa
greater capacity for aerobic metabolism and more capillaries surrounding them than Type IIx, thus showing a greater resistance to fatigue
-fast-twitch oxidative
Type IIx
fast-twitch glycolytic
Proprioceptors
specialized sensory receptors located within joints, muscles, and tendons that provide CNS w/ info needed to maintain muscle tone and perform complex coordinated movements.
-sensitive to pressure and tension
Muscle Spindles
proprioceptors that consist of several modified muscle fibers enclosed in a sheath of connective tissues
- when muscle is stretched, deformation of muscle spindles activates sensory neuron, sending impulse to spinal cord, which synapses w/ a motor neuron causing muscle contraction.
- opposite of GTO
Golgi Tendon Organ (GTO)
proprioceptors located in tendons near the myotendinous junction and are attached end-to-end w/ extrafusal fibers.
- when extremely heavy load is placed on muscle, discharge of GTO occurs. sensory neuron is GTO activate inhibitory interneuron in spinal cord, inhibiting motor neuron, thus reducing tension
- opposite of muscle spindles
L and R Atria
deliver blood into L and R ventricles
L and R Ventricles
supply the main force for moving blood through the pulmonary and peripheral circulations, respectively.
Tricuspid and Mitral valve (atrioventricular valve)
collectively called atrioventricular valve (AV)
prevent blood flow from ventricles back into the atria during ventricular contraction (systole).
Aortic and Pulmonary valve (Semilunar valves)
collectively called semilunar valves
-prevent backflow of blood from aorta and pulmonary arteries into ventricles during ventricular relaxation (diastole).
Sinoatrial (SA) node
small area of specialized muscle tissue located in the upper lateral wall of the R atrium.
-intrinsic pacemaker, where rhythmic electrical impulses are normally initiated
Atrioventricular (AV) node
impulse is delayed slightly before passing into the ventricles
-located in the posterior septal wall of the R atrium.
Atrioventricular (AV) bundle
conducts impulse to the ventricles
L and R bundle branch
further divide into the Purkinje fibers and conduct impulses to all parts of the ventricles.
-lead from AV bundle into ventricles
Myocardium
heart muscle
-inherent rhythmically and conduction properties are influenced by the cardiovascular center of the medulla, which transmits signals to the heart through the sympathetic and parasympathetic NS.
Sympathetic and Parasympathetic neurons supplied to:
Atria: both S and PS
Ventricles: alomst exclusively S
Normal RHR
60-100 beats/min
Bradycardia and Tachycardia
B: fewer than 60 beat/min
T: more than 100 beats/min
Electrocardiogram
graph representation of the electrical activity of the heart via the surface of the body
-consist of: P-wave, QRS complex (Q, R, and S waves), and T-wave
P-wave and QRS complex
recordings of electrical depolarization, that is the electrical stimulus that leads to mechanical contraction
Deplarization
reversal of membrane activity electrical potential
-the normally negative potential inside the membrane becomes slightly positive and the outside becomes slight negative
Repolarization
electrical potential generated as the ventricle recover the state of depolarization
-occurs in ventricular muscle shortly after depolarization
T-wave
caused by electrical potential generated as the ventricle recover the state of depolarization
Arterial system
carries blood away from heart
Venous system
returns blood toward heart
Arteries
rapidly transport blood pumped from heart
Arterioles
small branches of arteries that act as control vessels though which blood enters the capillaries
Capillaries
facilitate exchange of oxygen, fluid, nutrients, electrolytes, hormones, and other substances between blood and interstitial fluid in the various tissues of the body.
Venules
collect blood from capillaries and gradually converge into the progressively larger veins
Veins
transport oxygen-depleted blood back to heart
Hemoglobin
transport iron-protein of oxygen carried by RBC
-also an acid-base buffer and a regulator of hydrogen ion concentration
RBCs
major component of blood-contain large quantities of CO2 and H2O to facilitate CO2 removal
Trachea
first passage of air distribution to the lungs
Bronchi
second passage of air distribution to the lungs
Bronchioles
third and additional passage of air distribution to the lungs (23 total passages)
Alveoli
area in lungs where gases are exchanged in respiration
Primary function of Respiratory System
basic exchange of O2 and CO2
Pleural Pressure
pressure in the narrow space between the lung pleura and the chest wall pleura
Pleura
membrane enveloping the lungs and lining the chest walls
Alveolar pressure
pressure inside the alveoli when the glottis is open and no air is flowing into our out of the lungs.
Diffusion
a simple random motion of molecules moving in opposite directions through the alveolar capillary membrane.
-energy for diffusion is provided by kinetic motion of the molecules.
