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What is smooth muscle responsible for
Gi motility, constriction of blood vessels, uterine contractions
Which portions of the nervous system controll each type of muscle
Skeletal: somatic
How do skeletal muscles initial movement
they are connected on each side to different bones through tendons composed of collagen.
Describe the difference between the origin and the insertion
origin: muscle bone attachment near the center of the body usually stays in place
insertion: farther joint
What type of neurotransmitter is used at neuromuscular junctions
What is an antagonistic muscle and what is a synergistic muscle
Antagonistic is a movement in both directions Bis/tris
Synergistic is one way.
What is a fascile
the muscle tissue,and connective tissue bundles which allow for muscle flexibility
What is another name for muscle fibers
myofibers which are single muscle cells
Muscle cells have?
multinucleated syncytia formed by fusion of individual cells durring development. Invervated by a single nerve ending that stretches the length of the muscle.
what is the plasma membrane of muscle cells called and why is it special
sarcolemma. has plasma membran and additional layer of polysaccharide and collagen which helps cells fuse with the tendon
What are myofibrils
a small unit within a muscle cell that is responsible for the striated appearance that generate contraction.
What are the thin/thick filaments composed of?
thick: myosin
What denotes the boundry of sarcomeres
the two z lines, this is where actin filimants attach myosing does not attach here.
Describe the sliding filament model and how it works.
The thick fillaments hydrolyze atp ant its head and where myosin is attached to the actin in a cross bridge. This shortens the gaps between z lines.
Diagram the steps of a contractile cycle
1. binding of myosin head to myosin binding site(cross bridge)
2. power stroke: myosin head pulls the actin chain(ADP is released)
3. Binding of new ATP molecule causes release of actin by myosin
4. ATP hydrolysis occurs and cocks the head.
what does the troponin/tropomyosin complex do?
troponin: globular protein that binds Ca and undergoes a conformational change.
Tropomyosin: long fibrous protein which winds around thick filaments and blocks myosin binding sites. Regulates muscle contractions
What is special about the neuromuscular junction
it is the synapse between muscle and an axon terminus. It is elongated so it can depolarize a large area. motor end plate is myofiber at junction and it uses Ach
What is end plate potential
It is the depolarization of the postsynaptic membrane due to AcH opening Na+ receptors. 1 vesicle causes minature EPP
What is the function of acetylcholinesterase
It hydrolyzes AcH to choline and an acetly unit. Stops muscle flexing
What is the function of the transverse tubules(t-tubule)
An action potential needs to depolarize the entire myofiber to flex the muscle. Aps tend to stay near the membrane surface of the thick cells so these deep infoldings aid in this process
What is the function of the sarcoplasmic reticulium
it sequesters(active transport) Ca when an action potential is not achieved and releases it into the sarcoplasm when depolarization occurs(Voltage gated Ca channels)
What are the two ways to incres the force of contraction
by motor unit recruitment. activating more than one neuron.
Frequency summation where there are fast depolarizations and the contraction builds on itself
What is tetanus and what is the disease tetnus
A rapidly repeating series of stimulations that builds on the first. Tetnus is a bacterial toxin that moves through the neuron and causes depolarization and strong contractions
What molecule regenerates ATP in muscle quickly
creatine phosphate
What is the function of myoglobin
it stores O2 for the mitochondria of the muscle tissue
What happens when the muscle runs out of 02 in a long contraction
it uses the lactic acid cycle and ph drops. it is transported to the liver where it makes pyruvate
What is the cause of rigor mortis
it is the stiffening of muscles due to ATP exhaustion
What are the similarities of cardiac muscle to skeletal muscle
Presence of T tubules
Length-tension relationship= optimum length for great force
How does cardiac muscle differ from skeletal muscle
No syncytial(one nucleus)(has functional synctium because of intercalated disks which allow ion passage
Connection to other cells by intercollated disks
Contraction not dependant on motor neurons
Uses Voltage gatedNAKchannels
What are the inhibitory/exititory nerves of the cardiac tissue
The vagus(parasympathetic) releases ach and inhibits the heart contractions at the SA node. SA node stimulates contraction
Describe the cardiac action potential diagram
Rapid depolarization due to fast Na+ channels. Plateau phase due to Na+/Ca++ channels. Repolarization due to K+ channels
What is the significance of the plateau phase
longer duration of contraction(emptying of ventricles) Long refractory period to prevent disorganization of transmission impulses(tetanus/summation impossible)
How are smooth muscle and skeletal muscle similar
Respond to Ca++ use sliding of actin/myosin
How are smooth and skeletal muscle different
One nucleus:connected by gap junctions(functional synctia)
Action potential varies depending on location of the cell.
No sarcomeres(smooth)
Shorter and narrower
No T tubules
Sar Reticulum not important
No troponin/tropomyosin
Autonomic motor response
What is used instead of troponin in the smooth muscles
calmodulin and myosin light chain kinase. Calmodulin activats MLCK and myosin is phosphorylated.
What type of ion channels do smooth muscles use
slow na+ channels(10-20 times longer to get depolarization)can have slow wave with spikes in gut
What stimulates the heart muscle
NE from sympathetic nervous system
what is the difference in innervation between smooth and skeletal muscles
both motor. skeletal somatic and can only innervate one cell. smooth autonomic and can innervate multiple cells because of gap junctions
What are the 5 roles of the skeleton
Support the body
provide a framework for movement
Protect vital organs
Store Ca++
Hematopoiesis(red,white,platelet formation)
What is the difference between the axial and appendicular components of the endoskeleton
axial: skull, vertebral column, rib cage
appendicular: all the rest
What are connective tissues and what is the progenetor cell
cells and material they secrete. Fibroblasts: secrete collagen and extracellular elastin. adipocytes, chondrocytes, osteocytes
Describe loose connective tissue
Loose: adipose and material inbetween cells(extracellular matrix. composed of proteoglycans(protein core and glucosaminoglycans) hydrophylic
Basement membrane(collagen that seperates epithelial from connective tissue
Describe the dense connective tissue
bones, tendons, ligaments
Describe flat bone
scapula, ribs, skull: location of hematopoiesis and protect organs.
Describe long bones
Bones of limbs: movement have 2 epiphysis(shell of compact with core of spongy)
Diaphysis(tube of contact bone with yellow marrow)
What is bone marrow and where is it found
Spongy material:
yellow: in shafts of long bones inactive and fatty
red: within spongy pores of flat bones: site of erythropoiesis
What are the two principle ingredients of bones
collagen and hydroxyapatite(material consisting of calcium phosphate crystals) Collagen ordered and other stuff around it
What does spongy bone look like
very dissordered and has spikes of trabeculae
What does the compact bone look like
functional units of Haversian stystem or osteon.
Central haversian canal with blood, lymph vessels and nerves. rings called lamellae. Canaliculi to lacunae or osteocyte. Connected by gap junctions.
What are volkmans canals
channels that run perp to haversian canals to connect osteons
What cells produce cartlige and what are the three types
chondrocytes hyaline, elastic, fibrous
hyaline cartilage
Strong and flexible: larynx, trachea, articular cartilage of bone joints
Elastic cartilage
ear, epiglottis more flexible contains elastin
Fibrous cartilage
Rigind and strong. pelvis(pubic symphysis) and invertebral disks of spinal column.
Why do cartilage injuries take a long time to heal
low metabolic rate because of low blood flow
Describe the growth of bones
The epiphyseal plate between diaphysis and epiphysis have cartilage growing between them which causes elongation and replaced by bone. Stimulated by growth hormone and stopped by androgens and estrogen at puberty
Describe bone remodeling
degradation and synthesis of bone. osteoblasts lay down collagen and hydroxyapatite.
Osteoclasts dissolve the hydroxyapatite crystals like macrophage. lacuna is space where osteobast is inside bone. Osteoclasts cause incres in serum ca++/phosphate
What is the function of calcitonin
increase osteoblast activity decreases osteoclasts and decreases renal/intestinal Ca++ absorption
What does calcitriol do
From Vit D
Decreseas osteoblast activity in creases osteoclasts. incresease Ca++ absorption
What Does parathyriod hormone do
increses osteoclasts, decrease blasts, incres renal absorption of Ca++
What do ligaments do
Connect bones to other bones
What do tendons do
connect bones to tendons
What are synarthroses
sites where bones fuse together(immovable joints)
What are amphiarthroses
slightly moovable joints like vertibrae
What are diarthroses
movable joints like ball and socked and hinges
What is the synovial fluid
the fluid in the capsule that lubricates joints.
What is the articular cartlage
the surface between two connecting bones that is easily damaged and causes arthritis and stiffness
What are the tasks performed by the respitory system
Gas exchange
pH regulation
Thermoregulation(heat loss due to breathing)
Protection from disease and particulate matter
What does hyperventilation do to the blood
Reduces CO2 which reducus carbonic acid which raises the pH
What does hypoventilation do
makes the blood more acidic
What is the path of inhaled air?
nose-nasopharynx-pharynx-larynx-trachea-bronchi-bronchioles-aveolar ducts-alveoli
What are the functions of the larynx
Made of cartilage so airway will remain open.
Contains the epiglotis which seals the tracea durring swallowing to prevent entry of food.
contains the vocal cords
What are bronchiles composed of
smooth muscle and contain no cartilage. 1mm wide and allows for the regulation of the diameter to adjust air flow
Describe the alveoli
Tiny thin transparent sacks at the end of bronchioles that are 1 cell thick except where capillaries cross. Site of gas exchange
What is known as the conduction zone of the respitory system
the entire respitory tract down to the bronchioles. All tall columnar epithelial cells that dont allow gas exchange
What do goblet cells do
secrete specialized layer of sticky mucus
What is the function of the cillia in the columnar zone
They constantly force mucus twords the pharynx which can be swallowed or coughed out. Gets rid of pathagons and particles. Mucociliary escalator
What are the components of the respitory zone
The alveoli, alveolar ducts, and small bronchioles. All involed in gas exchange
What type of cells are found in the respitory zone
small epithelial simple squamous cells. Single layer.
What is the role of alveolar macrophages
mucus would retard gas exchange so these cells aid in disease prevention
What is the function of surfactant
It is a soapy substance that coats the alveoli and reduces surface tension which would cause alveolar collapse due to water cohesion. made from phospholipids, protein, and ions secreted by fat cuboidal cells which are metabolically active
How does inspiration occur
by contracting the diaphragm which enlarges the chest cavity
What drives expiration
the elastic recoil of the lungs which requires no muscle contraction
What would happen if the lungs were taken out of the chest cavity
they would collapse
What two structures line the chest cavity
parietal pleura: lines the chest cavity
Visceral pleura: lines the lungs
What is the pleural space
the narrow cavity between the two pleura. There is a negative pressure(vacuum) in this space so the membranes are drawn together. There is also fluid thatkeeps them together by surface tension
Describe the structure of the diaphragm
It is a skeletal muscle below the ribs between the abdomen and the chest cavity.It is shaped like a dome and when it contracts it flattens and draws the chest cavity to expand along with the intercostal muscles to allow for inspiration
What does the abdominal muscle do when experation occurs
it forces the diaphragm uppwords and further shrinks the lungs durring exertion
Describe the steps of inspiration
Diaphragm expands
volume of the chest cavity expands
pleural pressure decreases becoming more negative.
the lungs expand
the pressure in the alveoli becomes negative
Air enters the lungs/alveoli
When is the alveolar pressure exactly zero
at the endo of resting expiration and just after inspiration
What would be the result of a holein the lungs that allowed inhaled air to flow into the pleural cavity
Air would flow into the cavity causing the lungs to collapse. inspiration would be impossible due to the lack of negative pressure
What is spirometry
the measurement of the volume of air enterning the lung at various stages of respiration
What is Tidal volume
the amout of air that enters and exits the lungs during normal breathing is about 10% of the lung volume
What is the expiratory reserve volume
volume of air that can be epired after passive resting expiration
What is the inspiratory reserve volume
Volume that can be inspired after the relaxed inspiration
Inspiratory capacity
is the maximal volume of air which can be inhaled after resting expiration
Residual volume
the amount of air that remains in the lungs after the strongest possible expiration
Vital capacity
the maximal amout of air that can be forced out of the lungs after the deepest possible breath
What is the total lung capacity
the vital capacity and the residual volume added together
What is pulmonary edema
an increased blood pressure in the lungs that causes fluid to enter the lungs. Due to left atrium pressure increase. Usually prevented by lympocytes.
What can result from a high pulmonary capillary hydrostatic pressure
accumulation of interstitial fluid in the lungs
Fluid accumulation in the alveoli
Decreased oxygenation of the blood due to excess fluid and slowing 02 diffusion
What structures act as the respitory membrane
O2/CO2 has to diffuse across the alveolar epithelium, through the interstitial liquid and across the capillary endothelium. Lipid bilayers do not inhibit this flow
What drives oxygen into the alveolar capillaries
the oxygen pressure gradient between the alveolar air and the the oxygen in the blood
Why is the atmospheric P02 higher than the arterial P02
ph20 and pco2 are higher in the alveoli so the po2 must decrease
What has a higher oxygen affininty hb or myoglobin
What portion of the brain controls the involuntary process of breathing
the respitory control center in the medulla of the brain stem
What three chemical stimuli regulate respiration
PCo2 pH and po2 finally
How is breathing regulated
peripheral chemorecpetors in the aortic and carotid arteries.
Medullary respitory control center chemoreptors in the cns
What does the parasympathetic nervous system do to the lungs
it releases ACh into the smooth muscle of the large bronchioles. This is in response to irritation of the lung and prevents the irritation to spread.
What does epinepherine do in the lungs
it increses the ventilation and causes airway smooth muscles to relax.
What does asthma do and what do inhalers contain
Spasm in the airway smooth muscles. Inhalers contain epinephrine, antihistamines, and anticholinergics.
What happens in the lungs in response to a high pCo2
peripheral chemireceptors and medullary respiration control center receptors respond. Increased Co2 causes decrease in pH and this is what is sensed respitory rate increased
What happens in response to a low pH in the blood
increased respitory rate due to peripherial chemoreceptors and medullary respiratory center
What happens in response to a stretching of the lung
stretch receptors in the lung inhibit respiration
What happens in response to chemical irritation
irritation receptors of the lung start coughing or bronchoconstriction
What is the largest organ in the body by size and weight
the skin
What is the roll of the skin
to protect from pathogens, excess evaporation of water, and to regulate body temperature.
Diagram the layers of the skin
epidermis dermis subcutaneous tissue or hypodermis which is composed of fat an insulating layer
What is the epidermis composed of
a stratified(many layers) of squamous epithelial cells. which are constantly degredade and replenished by mitosis from the stratum basale(deep part of epidermis)
What happens when the epidermal cells die
they are keratinized and surrounded by keratin which helps in skin water proofing
What is the function of melanin
it is a pigment that is produced by specialized cells in the epidermis(melanocytes) which help absorb the uv light of the sun to prevent tissue damage
Does the epidermis have blood vessels
What are teh functions of the dermis sensory receptors
convey info about touch, pressure, pain, itch, and tickle to the cns
Where are the sudoriferous glands found
sweat glands are in the dermis
Where are the sebaceous glands found
oil glands are in the dermis
Where are hair follicles found and what are hairs composed of
dermis and they are composed of tightly bound epithelial cells that are dead.
Describe a sudoriferous gland
it is a structure that origionates in the dermis and leads through the epidermis via a pore on the skin surface. It allows loss of excess heat by evaporation
What is the effect of aldosterone on sweat composition
it causes the conservation of ions in high heat environments. so sweat has less salt
What is chemical thermogenesis or non shivering thermogenesis
the process of creating heat from brown fat tissue
What does the thyroid hormone do
increases temperature due to an increased metabolic rate it takes several weeks
How is day to day temperature regulated
contraction of skeletal muscles by shivering or moving. Skin insulates so heat is conserved. Constriction of dermis blood vessels minimizes heat loss in response to sympathetic nervous system pale skin.
What causes dissipation of excess heat
evaporation due to sweating and dilation of blood vessels.

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