Exam 1 Flashcards
Myology
The branch of anatomy that deals with skeletal muscular system
Contractility
Specific function of skeletal muscle is the the production of voluntary movement.
Functions of Skeletal Muscle
- ) Movement
- ) Stability
- ) Communication
- ) Control of body openings and passages
- ) Heat production
Musculoskeletal system
Composed of bones and joints of which body movements occur
Muscle fiber
Basic structural unit of a muscle
Fasiculi
Muscle fibers are grouped into bundles
Connective tissue
Muscle fibers and fasciculi are bound together by _________
Connective investment of muscle
Function:
- ) connect muscle to bone or other structure
- ) provides a route through which nerves and blood vessels reach the muscle fibers.
- ) provide a non-contractile framework which allows the contraction of a muscle fiber to be transmitted to bone
Endomysium
The delicate connective tissue sheath which surrounds each individual muscle fiber and connects it to adjacent muscle fibers
Perimysium
A more dense layer which surrounds each fasciculi and divides the muscle into a series of separate compartments.
Epimysium
The dense layer of connective tissue which surrounds the entire muscle and separates the muscle for the surrounding tissue, organs, and other muscles. The ______ is continuous with deep fascia in the area and will continue as the tendon of the muscle.
Myofibrils
The contractile units of the muscle and each fiber contains dozens to hundreds of these
Sarcolemma
Tough specialized membrane that each fibers are contained in.
Hypertrophy
The type of increase in the size of a muscle, which is due to an increase in the size of each individual muscle fiber.
Hyperplasia
An increase in the size of a muscle due to an actual increase in the number of muscle fibers. This method involves subjecting the muscle fibers to high resistance exercise which induce injury to the individual fibers, which is then followed by a regenerative process.
Sarcoplasm
Used to refer the cytoplasm of a muscle fiber. Muscles being classified as either red(dark) or white(light) is based on the amount of ________ within the majority of fibers found in the respective muscle.
Type 1 fibers (Dark)
- ) Aerobic (large amounts of sarcoplasm and myoglobin)
- ) extensive capillary beds
- ) slow twitch
- ) fatigue resistant
- ) numerous mitochondria
- ) more fatty acids/ less glycogen
- ) ATROPHY WITH IMMOBILIZATION
Type II fibers (light)
- ) Anaerobic (lesser amounts of sarcoplasm and myoglobin)
- ) fewer capillary beds
- ) fast twitch
- ) fatigue easier
- ) less mitochondria
- ) more glycogen/ less fatty acids
- ) ATROPHY WITH AGING
Intermediate fibers
> Exhibit characteristics which are somewhere between type 1 and type 2 fibers
> contract faster than type 1 but slower than type 2
> have a greater resistance to fatigue but histologically resemble type 2 fibers.
Sarcoplasm Reticulum
An elaborate, tubular network which functions to store and transport calcium ions to the myofibrils.
Transverse Tubules (T-System)
Tubular invaginations of the sarcolemma which allow electrical impulses to enter the muscle fiber and make their way to the myofibrils.
Myoglobin
A red protein pigment which is found in the sarcoplasm of the fiber. Also stores the oxygen needed for the fibers to utilize for metabolism.
Myofilaments
Longitudinally oriented bundles of thick and thin filaments
Sacromere
Myofibrils are composed of numerous of units that are the smallest functional unit of the muscle and anatomically runs from one z-line to the next z-line.
Contractile proteins
Actin: found mainly in I-bands
Myosin: found mainly in the A-bands
Regulatory Proteins
Act to inhibit the interaction of actin and myosin and thus prevent indiscriminate movement
Troponin (Ca bind directly) and tropomyosin
Calcium
Eliminates the inhibition caused by the regulatory proteins and thus allows muscle contractions to occur.
Nerve impulses from the transverse tubules stimulates the release of calcium from the sarcoplasmic reticulum.
ATP
The “fuel” of the muscle
The addition of _____ allows the system to operate, by allowing myosin to interact of a muscle.
Aerobic Pathway
> Take place in mitochondria
More efficient way to produce ATP; not the speediest
Prefers fatty acids to produce ATP
Fatty acids are stored in the body’s fat cells as triglycerides and released into the blood during exercise.
Anaerobic Pathway
> Depends on 2 substances to produce ATP:
> Creatine Phosphate- allows muscle to contract
> Glycogen- produces ATP by the process known as
glycolysis.
Glycogen is stored in either muscle fibers or liver cells.
Lactic Acid: byproducts of glycogen
Phase one
Will last for the first few minutes and creatine phosphate and glycogen are the primary fuel sources. As much as 20% of the total glycogen that is stored in a muscle may be utilized during this phase. (Anaerobic) “Needs to be quick”
Phase 2
Will see shift in metabolism to the more efficient aerobic metabolism and the use of fatty acids to produce ATP. “Long as possible”
Phase 3
Which occurs as exercise intensifies will see the muscle fibers going back to the anaerobic production of ATP and thus the utilization of the remaining stored glycogen. It is during this phase that lactic acid can accumulate within the fibers.
Carbo Loading
A dietary manipulation used to increase the store of glycogen in muscle fibers. The ability to utilize glycogen maybe more important that the ability to store it, so a well-trained athlete who already stores more glycogen than normal may gain little from the procedure.
Caffeine
> gets from phase 1 to phase 2 quicker
this effect on fatty acids should delay the utilization of glycogen
diuretic
Blood Doping/ Induced Erythrocythemia
This procedure is to increase the oxygen carrying capacity of red blood cells. This can increase their endurance and thus exercise longer. “Effects phase 1 and 3” “Increased blood cells; Increased fatty acids”
Risks associated:
- ) rashes and fevers
- ) acute hemolysis
- ) transmission of viruses
- ) fluid overload, which can lead to kidney damage and intravascular clotting of blood.
Erythropoietin (EPO)
Normally a naturally occurring hormone produced in the kidneys. Synthetic form of the hormone was produced for use of anemic patients.
Anabolic Steroids
Synthetic form of male hormone, testosterone, and was developed to try to separate the anabolic effect of the hormone from its androgenic effect.
Anabolic
The stimulation of protein synthesis and thus induction of growth
Androgenic
The development of secondary sexual characteristics
Oil based
Usually injected and have fewer side effects, but are detectable for several months, if not longer.
Water based
Usually taken in pill form, but have more side effects. However they are cleared from the system within 3-4 weeks.
Stacking
The user takes several forms of the drug (oil and water based)
Pyramiding
Is a procedure where the user starts with a low dosage, than raises to a peak and then begins to taper down he amount being taken.
Anabolic steroids short term side effects
- ) headaches, dizziness, and nausea
- ) acne, especially on the back
- ) shrinkage of the testicles
- ) increased aggressiveness
- ) GYNECOMASTIA
- ) TENDON DAMAGE
Anabolic steroids long term effects
- ) cardiovascular system
- ) digestive system (especially liver)
- ) reproductive system (the prostate)
- ) endocrine system
Anabolic steroids in females-side effects
- ) increase in the size of the clitoris
- ) decrease in the size of the mammary glands
- ) development of facial hair
- ) deepening of the voice
- ) tendon damage
Adolescents who take anabolic steroids
There is a premature of closing of the growth pates which leads to shortened stature as well as other problems.
Legitimate reasons that a physician would prescribe an anabolic steroids
- ) restore hormonal levels in males with low testosterone levels
- ) improve mood and alleviate depression
- ) patients who are chronically ill (ex: cancer) and become debilitated because of lack of appetite
- ) the drugs enhance appetitive and increase body weight and muscle mass
Chemical composition of muscle
> 75% water
20% protein (most abundant in myosin)
5% others
Highest protein is the eyeball it has 35% protein
Efferent/ motor impulses
Motor nerves transmit ________ from the CNS to each individual muscle fiber, the result of which is a motor response (contraction).
Motor unit
The single motor neuron (nerve fiber) and the group of muscles fibers it supplies is known as ______
Also the smallest part of the muscle which can contract independently
Precision type of activities
Contain motor units with fewer number of fibers
Non-precision type of activities
Ex: locomotion
Have motor units which can consists of thousands of motor fibers.
Motor unit anatomy
> The unit originates in a motor neuron in the ventral (anterior) horn of the grey matter of the spinal cord or brain stem (CNS)
> Continues as the spinal nerves and named peripheral nerves (PNS)
> The neuromuscular junction
> The sarcolemma of the muscle fiber (terminal end of the unit)
Neuromuscular Junction
A physiologically, biochemically and clinically complex portion of the motor unit.
> Presynaptic portion (the nerve ending)
Postsynaptic portion (sarcolemma of the muscle fiber)
Synaptic Cleft (space between the pre and post synaptic portions)
Myasthenia Gravis
> The most common neuromuscular junction disorder and an example of an autoimmune disorder
It produces abnormal antibodies which damage and destroy ACH receptors sites on the sarcolemma of the muscle fibers
It starts by affecting muscle supplied by cranial nerves (CN 7) and will progress to the extremities
Muscle weakness tends to get worse with exercise and gets better with rest
Many patients with this condition will suffer from hyperplasia of they thymus gland or a tumor to the gland (thymoma)
Pregnant mom has a 25% chance of having her infant born with the condition
Nicotine
> An example of a drug that is able to compete with ACH molecules in binding to the ACH receptor
It’s actions are much more prolonged than ACH
Snake Venom
> Contains both cytotoxins (destroy tissue/blood vessels) and neurotoxins (prevents binding ACH = no action potential)
Prevents ACH from binding to the ACH receptor sites
Unlike nicotine they do not cause an action potential to occur
Organophosphates
> Examples include parathion and malathion which are found in insecticides and are able to inactive the ACHe
ACH can no longer be rapidly degraded, resulting in an accumulation of ACH at the postsynaptic portion of the junction
Botulin Toxin
> Toxin that is released from the bacteria known as clostridium botulinum, which causes a sever type of food poisoning.
the toxin blocks the release of ACH from the presynaptic portion of the neuromuscular junction
first it affects the muscles by the cranial nerves but can progress to affect limb and respiratory muscles.
Sensory Nerve Fibers
Are involved with coordination, pain, and proprioception
Proprioceptors
> Are a category of sense organs that are found within the musculo-skeletal system.
Muscle spindles
Are an example of proprioceptors found scattered throughout a muscle and are fluid filled sac which contain specialized muscle fibers known as intrafusal muscle fibers (extrafusal muscle fibers are NOT found here)
Intrafusal muscles fibers
Have both efferent and afferent nerve fibers associated with it. They also detect stretch in a muscle.
Extrafusal muscle fibers
Are not found in muscle spindles and only efferent nerve fibers are associated with them
Golgi tendon organs
Located in tendons and detect stretch of the tendons, which triggers a reflect to inhibits muscle contractions and thus avoid injury to the muscles and its tendon.
Ex: think the box is heavy and then picking it up and its light
Origin
The end of the muscle which attaches to the more or less stationary part of the skeleton
Insertion
The end attached to the portion of the skeleton which moves when the muscle contracts
Belly
Term for flesh of the muscle which is surrounded by epimysium
Tendons
Connective tissue portion of the muscle (the continuation of the epimysium) which attaches to bone. Is also composed of collagen fibers. The arrangement of collagen fibers gives it is tensile strength.
> Also is strictly afferent!!!! (Sensory)
Tensile strength
Defined as the load necessary to rupture a given material when pulled in the direction of its length and allows muscles to withstand considerable amounts of pressure.
Tendons give muscles the following other advantages:
- ) improve leverage by concentrating the force of a muscle on a small area.
- ) economize space and maintain limb conformity
- ) acts as a damping tissue to absorb shock and limit potential damage to bone and muscle
- ) flexible, so that they can bend at joints
Sharpey’s Fibers
The collagen fibers will penetrate deeply into the bone is known as _______. The attachment is so strength that severe traction injuries happens and causes an avulsion fracture.
Bursa
Is a lubricating device that will develop between the tendon and another structure (skin, bone, another tendon) to limit friction and thus inflammation of the tendon.
> is a sac of CT that is filled with synovial fluid
Fascia
The musculature of the body is invested and separated from the skin, from other muscles and structures by sheets of CT known as _________
Intermuscular Septum: deep fascia
Between individual muscles (where the epimysium of one muscle meets the epimysium of another muscle)
Retinaculum: deep fascia
A thickened band of deep fascia which is found at joints and functions to bind down tendons and nerves that cross the joint.
Parallel/strap muscles
Type 2
Muscles where the fibers run approx. the whole length of the muscle.
Pennate muscles
Type 1 muscle
Fibers run oblique to the long axis of the muscle
Unipennate
Where the tendon lies along one side of the muscle and the fibers pass obliquely to the tendon
Bipennate
Tendon lies in the center of the muscle and fibers pass to it from each side
Prime mover/agonist
The muscle or muscles which are most responsible for carrying out a particular movement
Synergists
Assist the prime mover(s) in performing the action by giving more force for a movement, stabilizing a joint which the mover(s) pass over but do not move, or keep the bone of origin of the mover(s) steady
Antagonist
The muscle that produces the opposite effect from the agonist
Reciprocal innervation
When a muscle contracts, its antagonists automatically relaxes.
Co-Reflex Phenomenon
Both agonist and antagonists contract at the same time. Also seen in individuals with sensory nerve damage.
Can cause atrophy of the skeletal muscle
- ) pathology of the CNS (ALS)
- ) Pathology of the PNS (Guillain-Barre Syndrome)
- ) Pathology of the neuromuscular junction (myasthenia gravis)
- ) pathology of the individual muscle fibers (muscular dystrophy)
- ) injury to any of the above components
- ) prolonged immobilization of the joints or chronic joint disorders (use it or lose it)
Ischemic necrosis/ Ischemia
Diminishing of the vascular supply to a muscle, which will result in the loss of muscle fibers within a few hours
Ex: heart attack
Contracture
If a muscle remains in a shortened (contracted) state for a prolonged period of time, it will develop a persistent and sometime permanent shortening
Ex:polio
Satellite cells
regeneration of injured muscle fibers may occur to some degree due to the activity of undifferentiated myoblasts
> found between the endomysium and sarcolemma of the muscle fiber
> In muscular dystrophy they are prevented from replacing damaged muscle fibers
Reduction of size of muscles
Cross section of an athlete in their 20s = 90% skeletal muscle
Cross section of someone who is elderly = 30-40% muscle tissue
Older people typically have type 1 fibers
Shoulder girdle
Scapula and clavicle
Free limb
Consists of the arm, forearm, and hand
Arm/brachium
The area between the shoulder joint and elbow joint (humerus)
Forearm/antebrachium
Area between the elbow joint and wrist joint (radius and ulna)
Hand/manus
Area of the free limb that is distal to the wrist joining (carpals, metacarpals, and phalanges)
Clavicle
It forms the boundary between two well marked depression, one of which is superior to the medial third of the bone (Supraclavicular fossa) and the other is inferior to the lateral third of the bone (infraclavicular fossa)
Females normally shorter than males
Also the transitional bone between the axial and appendicular skeleton and shows characteristics of both
Transmits forces from the upper extremity to the axial skeleton and acts a brace holding the arm free from the rest of the body
Intramembranous ossification
The bone cells replace a primitive type of connective tissue known as mesenchyme
(All bone from axial)
Endochondral ossification
The bone cells replace a very well developed type of connective tissue known as hyaline cartilage
(All Appendicular bones)
Clavicle ossification
First bone to go through ossification (5th & 6th week of development)
Two primary centers for ossification (growth plates):
- ) Center of bone-intramembranous
- ) Sternal end of the bone-endochondral (17 years old)
Last bone to complete its ossification
Fractures of the clavicle
It is one of the most frequently fractured bones in the body (normally first curvature = weakest)
Usually due to indirect forces on the shoulder which is greater than the strength of the bone
Cleidocranial Dysotosis
Is a hereditary condition in which ossification is abnormal. The clavicle can be missing or abnormally formed. It’s typically bilateral in most patients.
Scapula
A large, triangular, flat bone found in the posterior aspect of the thoracic cage.
Found between the 2nd and 7th rib and the 1st and 7th thoracic vertebrae
Not a transitional bone like the clavicle
Acromioclavicular joint
Scapula bones articulate with the acromial end forte clavicle to form this
Shoulder joint
The acromioclavicular joint and the head of the humerus form this
Ossification of the scapula
Has 7 ossification centers (1 primary and 6 secondary)
Primary center- body of the bone (fossa and spine) around the 8th week of development
6 secondary centers- 2 for the acromion; 2 for the coracoid process; and 1 each for the medial border and inferior angle.
Bone completes its ossification between 15 and 18 years old.
Fractures of the scapula
Least common fracture
Usually the result of severe direct trauma
Sprengel’s deformity
An undescended scapula brought about by attachment to cervical vertebrae by either bone, cartilage, or fibrous attachment.
Os Acromidae
Failure of the acromion process to fuse with the rest o the bone (common)
Primary functions of Mammary glands
- ) provide nourishment to the infant
2. ) Protection against certain types of disease in infants (immune benefits)
Nipple and areola
External parts of the mammary glands
Nipple
Papillae like projection with the opening of the lactiferous ducts
Composed of smooth muscle and are considered tactile sense organs
Sebaceous glands
Secrete an oily substance that provided a protective lubricant for the areola and nipples during lactation.
Lobes—>lobules—>alveoli
Internal anatomy of the mammary glands
Alveoli
The secretory portion of the glands and are lined with secretory cells. Can be in resting or inactive state.
Changes in the mammary glands
At puberty: increases rapidly in size
At menstrual period: tend to enlarge slightly and to exhibit tenderness
At pregnancy: become enlarged and functional, attaining their greatest development during lactation. After lactation they return to normal size.
Menopause: undergo atrophy
Estrogen
Secreted by the ovaries and placenta and promotes the growth of the duct system of the glands
Progesterone
Secreted by the ovaries and placenta, promotes the growth of the secretory cells
Prolactin
Secreted by the anterior pituitary, promotes the production of milk after brith
Oxytocin
Secreted by the posterior pituitary, promotes the release of milk
Progesterone and estrogen
Promote the development of the alveoli, but together suppress milk production
Colostrum
This is the first secretions from the functional mammary glands.
Rich in immunoglobulins and lactoferrin to impart immune function
Transitional milk
Present from about day 6 to day 15 and has lower immunoglobulin level as compared to colostrum, but higher amounts of lactose and fat
Mature Milk
Present from day 15 to weaning
88%water
7% lactose
4% fat
1% protein
Inverted nipples
Retracted nipple (congenital or recent event). If it is a recent event, the cause maybe an underlying carcinoma of the lactiferous ducts
Supernumerary nipples
Extra nipples which may or may not be associated with mammary gland tissue
Adenocarcinoma
A type of breast cancer that usually arise from the epithelial cells of the lactiferous ducts
Increased risk factors of breast cancer
- ) family history
- ) Never having had a child
- ) having your first child after the age of 35
Chronic cystic Mastitis
Benign tumors are much more common that cancerous growths
Usually found after menstrual period and during periods of hormonal irregularities
Galactorrhea
Secretions from the breast which is not associated with pregnancy or lactation
Underlying pathology, medication hormonal abnormalities or breast cancer
Gynecomastia
The enlargement and development of breast tissue in males
Can be estrogen producing tumor
Humerus
Largest and longest bone of the upper extremity and consists of a shaft and 2 distinct ends
Ossification of the humerus
Develops from 8 ossification (1 primary and 7 secondary)
Primary center- shaft and develops very early in fetal development
Secondary center- after birth to late adolescents and include center for the head, greater tuberosity, lesser tuberosity, medial epicondyle, lateral epicondyle, capitalism, and trochlea
Areas that are prone to fractures are the anatomical and surgical necks, greater and lesser tubercles, and shaft, and the distal end.
Fractures of the humerus
Fractures of the surgical neck can damage
Damage to the auxiliary nerve and numeral circumflex blood vessels due to this injury
Fractures of the shaft affect
Damage to the radial nerve due to this injury
Fractures of the distal end fo the bone
Damage to the median and ulnar nerves and brachial blood vessels are due to this injury
Elevation
An upward movement of the scapula while the scapula remains approximately parallel to the vertebral column
Depression
The return to normal from a position of elevation
Abduction/protraction
A lateral movement of the scapula away form the vertebral column with the medial border remaining parallel to the column
Adduction/ retraction
Medial movement of the scapula toward the vertebral column
Pectoralis major
It’s tendon of insertion forms the anterior fold or wall of the axilla
Poland syndrome
Both the pectoralis major and minor muscles are missing and there is atrophy of the mammary glands.
The hand on the affected side is smaller and may show webbing between the digits which is called syndactylism
Axilla
Apex- clavicle, scapula, and the 1st rib
Base- made up of skin and fascia
Anterior wall- pectoralis major
Posterior wall- latissimus dorsi and Teres major
Medial wall- serrated anterior and upper ribs
Lateral wall- proximal medial aspect of the arm
Contents include brachial plexus, axillary artery and vein, lymph nodes and adipose tissue.
Axillary sheath
The deep fascia that encloses the brachial plexus and the blood vessels
Prefixed brachial plexus
Is a plexus in which C4 is the most superior spot all root forming the plexus, C8 would be the most inferior spinal nerve
Postfixed brachial plexus
Is a plexus in which C6 is the most superior spinal nerve root, T2 would be the most inferior spinal nerve root
Paralysis
Complete loss of muscular movement
Paresis
Movement can be performed but is weak (incomplete paralysis)
Anesthesia
Partial or complete loss of sensation with or without loss of consciousness
Parenthesis
Loss of cutaneous sensation (subdivision of anesthesia)
Erb-Duchenne Palsy
Most common type of injury to the plexus where the C5 or C6 are damaged or comprised
They are caused by excessive stretching of the neck and heavy weight falling on shoulder and producing a traction injury.
Klumpke’s Palsy
These injuries are less common and the result is in an injury of C8 or T1
The most common cause is by forceful abduction of the humerus at he shoulder joint
Cervical ribs
A longer than normal transverse process of a cervical vertebrae which can cause problems with the spinal nerves from the plexus
Compression of the cords of the brachial plexus
May result from prolonged hyperabduction of the arm during certain manual tasks such as painting a ceiling.
Can result in parenthesis and possible hand and digit weakness
Thoracic outlet syndrome
Both compression of the cords of the brachial plexus and the axillary artery. Symptoms include both neurological and vascular
