HLTH: review of muscle and integumentary Flashcards
what is the function of unique markings on bones?
to provide an attachment site for tendons or for the passage of nerves and vessels
functions of bones
movement, protection for the viscera, and metabolic storage of calicum
bone matrix
collagen fibres and calcium phosphate salts (hydroxyapatite)
dynamic equilibrium of bone
osteoblasts produce new bone and osteoclasts degrade bone
what is the bone stem cell and where is it derived from?
osteoprogenitor cells which are derived from embryonic mesenchymal cells
what do osteoprogenitor cells divide into?
osteoblasts
osteoblast function
secrete new bone matrix
what do osteoclasts come from?
macrophage progenitor cells
osteoclast function
resorption of bone tissue
two types of bones
compact and spongy
spongy bones
less dense and form the interior structure of bones; these lack haversian systems
epiphyseal plate
is the site of longitudinal bone growth and this is promoted by growth hormone and sex hormones
epiphyseal line
is the epiphyseal plate in adulthood once growth ceases; this stops when the epiphyseal plate ossifies
what kind of CT is articular cartilage?
hyaline cartilage
hormones that change bone density?
growth hormone, PTH, or cortisol
osteoporosis
the loss of bone density caused by loss of calcium salts; common in older women
what is the bone covered with?
periosteum which is a fibrous CT; it is also covered by articular cartilage at tips of bones
what does the periosteum contain?
osteoblasts, blood vessels, nerves, and lymphatics
what is the medullary cavity lined with?
endosteum that contains osteoblasts
where is red bone marrow found?
the cranium, vertebral bodies, ribs, sternum, and ilia
four basic functions of skeletal muscle
to facilitate body movement by muscle contraction, to maintain body position by muscle tone, to stabilize the joints and prevent excessive movement, and to maintain body temperature
involuntary skeletal muscle movement
occurs for respiratory movement, postural reflexes, blinking, shivering, or certain facial expressions
what creates striated appearance?
the arrangement of actin and myosin filaments within the muscle fibres
3 muscle layers
epimysium, perimysium, and endomysium
epimysium
surrounds the entire muscle
perimysium
surrounds the muscle fascicles
endomysium
surrounds the individual muscle fibres (cells)
motor unit
is the motor neuron of the spinal cord and all the muscle fibres it stimulates
neuromuscular junction
is where the synapse between the end of the motor nerve and the receptor site in the muscle fibre is located
what neurotransmitter is released for muscle contraction?
acetylcholine
acetylcholinesterase
is the enzyme that inactivated ace
myofibrils
each muscle cell contains this and it is made up of smaller myofilaments consisting of actin and myosin filaments
blood vessels during exercise
are dialated to promote greater blood flow into the muscle, thus increasing the supply of O2 and nutrients to provide energy for contraction
myoglobin
is stored in muscle fibres and can store limited amounts of O2
where is glycogen stored?
in muscle
aerobic respiration
produces ATP for muscle fibres as long as O2 is made available from the myoglobin
anaerobic respiration
occurs if the O2 supply does not meet the demand, using glucose as the primary energy source; produces lactic acid
respirations during exercise
are a result of anaerobic respiration in which an acidosis state is present, and respirations serve to compensate to reduce acidosis
lactic acid
is produced during anaerobic respiration and can cause local muscle pain and cramping
muscle cramp
is pain resulting from a strong muscle contraction or spasm, usually caused by local irritation from metabolic wastes
muscle spasms
reduce blood flow, thus leading to ischemic pain
tendons
attach muscles to bone and are usually the extension of the perimysium
origin
is at a joint and is the fixed bone
insertion
the bone that is moved by the muscle contraction
ligaments
attach bones
function of antagonistic muscles
prevent excessive movement and provide better control of movements
muscle growth
muscles cannot undergo mitosis but do undergo hypertrophy
aerobic or endurance exercise
increases the muscles capacity to work for longer without causing hypertrophy of the muscle; such exercise increases the capillaries and blood flow in a muscle, as well as mitochondria and myoglobin content
anaerobic or resistance exercise
focuses on increasing muscle strength by increasing muscle mass (hypertrophy)
anabolic steriods
synthetic hormones that are similar to testosterone and help to increase muscle strength and mass by increasing the anabolic effects/protein synthesis
side effects of anabolic steroids
liver damage, cardiovascular disease, personality changes, emotional lability, and sterility
atrophy
muscle cells size decreases when the muscle is not used; muscles become weak and flaccid
muscle twitch
results from increased irritability of the motor nerves supplying the muscle and can be caused by hypocalcemia
what is the function of joints accomplished by?
tendons and ligaments
3 types of joint movements
synarthroses, amphiarthrosis, and diarthrosis
synarthroses
immovable joints; ex. sutures in the skull
amphiarthrosis
slightly moveable joints, in which the bones are connected by fibro or hyaline cartilage; ex. joints in the ribs, sternum, and the pubic symphysis
diarthroses
aka synovial joints; freely movable joints
what is synovial fluid produced by?
the synovial membrane or synovium
what is the articular capsule composed of?
synovial membrane, the fibrous capsule, and sharpey fibres
the TMJ
is the only moveable joint in the skull and face; it has two synovial cavities and a central articular cartilage of dense collagen cavity
EMGs for muscle contraction
measure the electrical change associated with muscle contraction and are helpful in differentiating muscle disorders from neurologic disease
how is muscle dystrophy confirmed?
muscle biopsy
how are joints visualised?
by arthroscopy (which is the insertion of a lens directly into the joint) or by MRI
what is elevated in those with muscle diseases?
serum creatine kinase
function of creatine kinase
is an enzyme with an essential role in energy storage and may leak out of damaged cells into body fluids
functions of skin
provides the first line of defense, prevents excessive fluid loss, controls body temperature, has sensory perception, and synthesis and activation of vitamin D
two main layers of the skin
epidermis and the dermis (as well as accessory structures such as hair follicles)
five basic layers of the epidermis
stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, and stratum corneum
stratum basale
the base layer of the epidermis and new cells undergo mitosis here, then move upwards
stratum spinosum
spiny layer that is the second layer located above the basale; consists of irregularly shaped cells with intercellular connections called desmosomes; cells are rich in RNA and contribute to keratin synthesis
stratum granulosum
third layer above the spinosum layer and where keratin formation begins
keratin
is a protein found in skin, hair, and nails that prevents both loss of body fluid and entry of excessive water into the body
stratum lucidum
is a clear layer above the granulosum layer and is composed of degenerating keratinocytes that are flattened and willin with eleidin; only found in thicker skin
stratum corneum
aka horny and most superficial layer; it is composed of dead, flat cells that are being shed; cells are filled with keratin fibres formed from the eleiden, making them a waterproof barrier
keratinization
is the process of the cells forming in the stratum basale and moving upward and filling with keratin to eventually end up on the surface
melanocytes
specialized pigment-producing cells, in which the amount of melanin determines skin colour
albinism
is a recessive congenital disorder in which the body lacks production of melanin; the individual has white skin and hair and lacks pigment in the eyes
vitiligo
refers to small areas of hyperpigmentation that may gradually spread to involve larger areas
melasma
aka chloasma; is patches of darker skin, often on the face that may develop during pregnancy
dermis
thick layer of CT that contains elastic and collagen fibres
papillae
the junction of the dermis with the epidermis
accessory structures of the skin
hair follicles, sebaceous glands, and sweat gland (eccrine or aporcine)
sebaceous glands
are associated with hair follicles or open up directly onto the skin; they produce an oily secretion called sebum that keeps the hair and skin soft
two types of sweat glands
eccrine (merocrine) and apocrine
eccrine glands
are located all over the body and secrete sweat through pores onto the skin
apocrine sweat glands
are located in the axillae, scalp, face, and genitalia
why does sweat smell?
bacteria action by normal flora cause odor to develop
what is beneath the dermis?
the subcutaneous tissue or hypodermis
structures in the hypodermis
CT, fat cells, macrophages, fibroblasts, blood vessels, and nerves
