Exam 3 Flashcards
3 basic types of movements
gliding
angular movements
rotation
what is gliding?
where does it occur?
nearly flat surfaces of 2 bones slip across each other
at joints between the carpals and tarsals and between flat articular processes of vertebrae
what are angular movements?
increase or decrease the angle between two bones
flexion, extension, abduction, adduction, circumduction
what is flexion?
give examples
decrease the angle between bones by bringing the bones closer together
- making a fist, bringing head forward, bringing arms forward
what is extension?
give examples?
increases the angle between the joining bones and is a straightening action
- straightening fingers after making a fist, bending head backwards, bringing leg back
what is abduction?
give examples
movement of a limb away from the body midline
- raising arm or thigh laterally, spreading fingers or toes apart
what is adduction?
give examples
movement of a limb towards the body midline
- bringing arm or thigh back towards the body laterally
what is circumduction?
moving a limb or finger so it describes a cone in space
(moving in a circle)
what is rotation?
give examples?
the turning movement of a bone around the longitudinal axis
- turning legs out
_____ is the only movement allowed between the first 2 cervical vertebrae
rotation
4 functional properties of muscle tissue that distinguish it from other tissues
1) contractility - actin and myosin create contractile force in every cell in the body
2) excitability - nerve signals or other stimuli excite muscle cells, causing electrical impulses to travel along the cells’ plasma membrane
3) extensibility - can be stretched, contraction of one skeletal muscle will stretch an opposing muscle
4) elasticity - after being stretched, muscle tissue recoils passively and resumes its resting length
describe skeletal muscle tissue
located in skeletal muscles, discrete organs that attach to and move the skeleton
- striated
- elongated, cylindrical cells
- voluntary movement
describe cardiac muscle tissue
occurs only in the wall of the heart
- striated muscle
- contractions are involuntary
describe smooth muscle
found in the hollow internal organs other than the heart
- lack striations
- cells are elongated
- involuntary movement
cardiac muscle and smooth muscle are collectively called _____ muscle
visceral
what is a sarcomere?
the contractile unit composed of myofilaments made up of contractile proteins
what is a myofilament?
contractile myofilaments have 2 types - thick and thin
- thick filaments contain bundled myosin molecules
- thin contain actin molecules plus the regular proteins troponin and tropomyosin
- the sliding of the thin filaments past the thick filaments produces muscle shortening
what is a myofibril?
rodlike contractile organelles that occupy most of the muscle cell volume
- composed of sarcomeres arranged end to end, they appear banded, and the bands adjacent myofibrils are aligned
what is a muscle fiber (cell)?
an elongated multinucleate cell
- has a banded (stiated) appearance
- surrounded by the endomysium
what is a fascicle?
a discrete bundle of muscle cells, segregated from the rest of the muscle by a connective tissue sheath
- surrounded by a perimysium
what is a muscle organ?
consists of hundreds to thousands of muscle cells, plus connecting tissue wrappings, blood vessels, and nerve fibers
- covered extenerally by the epimysium
what are the 3 connective tissues in and around a skeletal muscle
epimysium
perimysium
endomysium
describe the epimysium
outer layer of dense irregular connective tissue surrounding the whole skeletal muscle
describe the perimysium
within each skeletal muscle, the muscle fibers are separated into groups (fascicle)
surrounding each fascicle is a layer of fibrous connective tissue
describe the endoysium
within a fascicle, each muscle fiber is surrounded by a fine sheath of loose connective tissue consisting mostly of reticular fibers
what is an origin?
the attachment of the muscle on the less movable bone
what is an insertion?
attachment on the more lovable bone
when a muscle contracts, the ____ is pulled towards the ____
insertion
origin
what is a direct attachment?
the attaching strands of connective tissue are so short that the muscle fascicles themselves appear to attach directly to the bone
what is an indirect attachment?
the connective tissue extends well beyond the end of the muscle fibers to form either a cordlike tendon or a flat sheet called an aponeurosis
- more common than direct
the light and dark bands on muscle fibers are a result of rod-shaped organelles called _____
myofibrils
a myofibril is composed of repeating segments called _____
sarcomeres
the boundaries at the 2 ends of the sarcomere are called _____
Z discs
Attached to each Z disc are extending towards the center of the sarcomere are many fine myofilaments called _____
thin (actin) filaments
the thin filaments are composed primarily of the contractile protein _____
two regulatory proteins, _____ and ______ are also found
actin
troponin
tropomyosin
what is tropomyosin?
forms a thin strand that spirals around the actin molecule
what is troponin?
a globular protein with 3 binding sites:
- one for actin
- one for tropomyosin
- and one for calcium
- attaches the tropomyosin strand to the actin molecule
in the center of the sarcomere and overlapping the inner ends of the thin filaments is a cylindrical bundle of _____
thick (myosin) filaments
what is ATPase and where does it come from?
an enzyme that splits ATP to release the energy required for muscle contraction
thick (myosin) filaments
the dark bands of a sarcomere, along the ends of the thin filaments, which overlap the thick filaments is called the _____
A band
the central part of the A band where no thin filaments reach is the _____
H zone
the _____ is the center of the H zone that contains tiny rods that hold the thick filaments together
M line
the two regions on either side if the A band, regions that contain only thin filaments are called _____
I bands
the _____ of the sarcomeres create the light portions of the light-dark pattern of striations seen along the length of any skeletal muscle
I bands
describe the sliding filament mechanism of muscle contraction
- initiated by the release of calcium ions from the sarcoplasmic reticulum and the binding of those ions to the troponin molecule on the thin filament
- this results in a change in shape of the troponin which moves the tropomyosin molecule and exposes the binding sites on the actin filament for the myosin heads
- contraction results as the myosin heads of the thick filaments attach to the thin filaments at both ends of the sarcomere and pull the the thin filaments towards the center of the sarcomere by pivoting inward
- after the myosin head pivots at its “hinge” it lets go, returns to original position, binds to the thin filament farther along its length and pivots again
what is concentric contraction?
a muscle generates force while shortening
- sliding filament mechanism
1) myosin heads attach to the actin in the thin filament, then pivot to pull the thin filaments towards the M line
2) freeze fracture TEM through the A band of a sarcomere showing myosin heads attached to the thin filaments
what is eccentric contraction?
a muscle generates force while lengthening
- essential for controlled movement and resistance to gravity
how does the length of a muscle fiber (how stretched or contracted it is at a given moment) impact the force it can generate?
the optimal length occurs when a fiber is slightly stretched so that its thin and thick filaments over-lap only to a moderate extent
- if a muscle fibers are stretched too much that the thick and thin filaments do not overlap at all then the myosin heads have nothing to attach to and no pulling force can be generated
- the sites of muscle attachments tend to keep muscles within the optimal range that joints normally do not let any bone move so widely that its attached muscles could shorten or stretch beyond their range
what are the 3 types of muscle fibers?
slow oxidative
fast glycolytic
fast oxidative
describe slow oxidative fibers
- obtain their energy from aerobic metabolic reactions and have a large number of mitochondria and rich supply of capillaries
- thin and red (abundance of myoglobin
- contract slowly
-resistant to fatigue as long as enough oxygen is present - prolonged contractions
- do not generate much power
describe fast glycolytic fibers?
- pale (contain little myoglobin)
- twice as thick as slow oxidative, contain more myofilaments, and generate more power
- depend on anaerobic pathways to make ATP, contain few mitochondria and capillaries
- glycosomes as fuel source
- muscles of upper limbs
describe fast oxidative fibers?
- contract quickly
- oxygen dependent
- high myoglobin content
- large number of mitochondria
- large supply of capillaries
- aerobic metabolism
- fatigue resistant but less so than SO
- intermediate speed of contraction
- lower limbs
how does the arrangement of fascicles in muscle impact range of motion (how far the muscle will move something when contracted) vs force generation?
- the more parallel the fibers are the more the muscle can shorten resulting in a larger range of motion, but do not have large force generation
- power of muscle depends more on total fibers it contains
describe a first class lever
fulcrum is located between the load and the point at which the effort is applied (see saws)
- can operate at either mechanical advantage (for power) or mechanical disadvnatage (speed and distance) depending on lengths of the load
describe a second class lever
the load and the effort are on the same side of the fulcrum
- effort is applied farther away from the fulcrum than the load (wheelbarrow)
- effort is longer than the load
- mechanical advantage (power)
- standing on ur toes
describe a third class lever
effort is applied closer to the fulcrum than the load
- load is longer than the effort
- mechanical disadvantage (speed and distance)
- flexion of the forearm by the biceps
- positioning of muscle insertions close to the joint, providing stability for fast movements like running
describe antagonist muscles
- oppose or reverse a particular movement
- usually contract lightly during movement to keep movement from overshooting or slow it near its completion
describe synergist muscles
- help the prime movers by either adding a little extra forcer to the movement being carried out or by reducing undesirable extra movements that the prime mover may produce
- some prime provers can cross several joints and cause movements of all of them and synergists act to cancel some of these movements
what are muscle compartments?
in the limbs, dense fibrous connective tissue divides the extensor (dorsal) and flexor (ventral) muscle masses into anatomical compartments
- group muscles of similar development origin and function
how does the thick fascia wrapping compartments become a problem if injuries occur?
- it prohibits the compartment from expanding during swelling, so pressure in the compartment increases and compress the vessels and nerves resulting in pain
- this also impedes venous draining from the compartment further increasing pressure
the heart lies in the thorax ____ to the sternum and costal cartilage and rests on the _____ surface of the diaphragm
posterior
superior
the heart assumes an _____ position in the thorax, with its pointed _____ lying to the left of the midline and _____ to the rest of the heart
oblique
apex
anterior
the _____ _____ point of the heart lies on the right where the costal cartilage of the third rib joins the sternum
superior right
the _____ _____ point of the heart lies at the costal cartilage of the second rib on the left, a finger’s breadth lateral to the sternum
superior left
the _____ ______ point of the heart lies at the costal cartilage of the sixth rib on the right, a finger’s breadth lateral to the sternum
inferior right
the _____ ______ point of the heart (apex point) likes on the left in the fifth intercostal space at the midclavicular line
inferior left
the _____ is the triple-layered sac that encloses the heart
pericardium
what are the 3 layers of the pericardium and what is their function?
outer layer: fibrous pericardium
- strong layer of dense connective tissue, acts as a tough outer coating that holds the heart in place and keeps it from overfilling with blood
serous pericardium
- a double-layered closed sac sandwiched between the fibrous pericardium and the heart
- parietal layer of the serous pericardium: adheres to inner surface of the fibrous pericardium
epicardium
- lies on the heart and is considered part of the heart wall
what are the 3 tissue layers of the heart wall?
epicardium
myocardium
endocardium
describe the epicardium
superficial visceral layer of the serous pericardium of the heart
- often infiltrated with fat, especially in older people
describe the myocardium
middle layer
forms the bulk of the heart
- consists of cardiac muscle tissue and is the layer that actually contracts
- connective tissue surrounds the muscle cells and create bundles that squeeze blood through the heart in the proper direction
- forms the interior cardiac skeleton
describe the endocardium
deep layer of the heart
a sheet of simple squamous epithelium resting on a thin layer of connective tissue
- lines the heart chambers and covers the heart valves
what are the 2 internal septa of the heart creating the 4 chambers?
interatrial septum - between the atria
inter ventricular septum - between ventricles
what the the 3 external grooves marking the boundaries between the 4 chambers?
the coronary sulcus - horizontal boundary between atria and ventricles
anterior inter ventricular sulcus - vertical marking the anterior position of the inter ventricular sulcus
posterior interventricualr sulcus - separates the two ventricles on the hear’s inferior surface
what are the chordae tendineae?
strong bands (heart strings) project superiorly from the papillary muscle to the flaps (cusps) of the tricuspid (right AV) valve
what are the 4 valves of the heart and their location?
located at the junctions of the atria and their respective ventricles are the AV valves: right AV (tricuspid) and left AV (bicuspid) valve
located at the junctions of the ventricles and the greater arteries: aortic and pulmonary semilunar valves
where is the cardiac skeleton and what are its four functions
lies in the plane between the atria and the ventricles and surrounds all four heart valves rather than handcuffs
composed of dense connective tissue
1) anchors valve cusps
2) prevents over dilation of the valve openings as blood pulses through them
3) point of attachment for the bundles of cardiac muscle in the atria and ventricles
4) blocks the direct spread of electrical impulses from the atria to the ventricles
describe the pathway of the flow of blood through the heart
oxygen poor blood goes in superior vena cava and inferior vena cava ->
right atrium ->
tricuspid valve ->
right ventricle ->
pulmonary semilunar valve ->
pulmonary trunk ->
lungs (pulmonary capillaries) ->
oxygen rich blood to heart via the 4 pulmonary veins ->
left atrium ->
mitral valve ->
left ventricle ->
aortic semilunar valve ->
aorta ->
body
what is systole?
contraction of the heart chamber
what is diastole?
time during which a heart chamber is relaxing and filling with blood
what are the three major coronary arteries supplying the heart wall with blood?
????
left coronary artery: arises from left side of aorta, passes posterior to the pulmonary trunk, then divides into the anterior interventricualr and circumflex arteries
right coronary artery: emerges from the right side of the aorta and descends in the coronary sulcus on the anterior surface of the heart, between the right atrium and the right ventricle
why is the anterior interventricular branch (left anterior descending artery) of the LCA commonly referred to as the Widowmaker artery?
its where plague builds up and complete blockage can occur
oxygenated blood cannot reach the heart
the walls of blood vessels, except the very smallest, are composed of 3 distinct layers - the tunica intima, tunica media, and tunica external - that surround the central blood-filled space, the _____
lumen
the innermost tunic if a vessel wall is the _____ _____, which is in “intimate” contact with the blood in the lumen
tunica intima
the tunica intimacy contains the _____, the simple squamous epithelium that lines the lumen of all vessels
endothelium
in vessels larger than 1mm, a thin layer of loose connective tissue, the _____ _____, lies just external to the endothelium
subendothelial layer
the middle tunic, or _____ _____, consists primarily of circularly arranged sheets of smooth muscle fibers, between which lie circular sheets of elastin and collagen fibrils.
tunica media
the outermost layer of the vessel wall is the _____ _____
tunica externa
the larger arteries and veins have tiny arteries, capillaries, and veins in their tunica externa called _____ _____ which arise either as tiny branches from the same vessel or as small branches from other, nearby vessels and nourish the outer half of the wall of the larger vessel
vasa vasorum
_____ _____ are the largest arteries near the heart - the aorta and its major branches - with diameters ranging from 2.5cm to 1cm.
elastic arteries
why is the aorta an elastic artery?
the elastic components in the vessel expand in response to increased blood pressure, in effects storing some of the energy of the flowing fluid
- when the heart relaxes, the elastic elements recoil, propelling the blood onward
_____ _____ lie distal to the elastic partiers and supply groups of organs, individual organs, and parts of organs
muscular arteries
what is the role of the tunica media in muscular arteries?
by actively changing the diameter of the artery, this layer regulates the amount of blood flowing to an organ according to the specific needs of that organ
a wavy _____ _____ _____ forms the other layer of the tunica intima
internal elastic membrane
an _____ _____ _____ forms the outer layer of the tunica media
external elastic membrane
_____ are the smallest arteries
arterioles
_____ are the smallest blood vessels
capillaries
in continuous capillaries, there are gaps of unjoined membrane called _____ _____ that allow small molecules to pass into and out of the capillary
intercellular clefts
smooth muscle cells called _____ _____ wrap around the root of each capillary where it leaves the metarteriole
precapillary sphincter
what is the function of precapillary sphincters in regulating blood flow?
regulate blood flow through the capillary bed according to that tissue’s need for oxygen and nutrients
- when the tissue is functionally active, the sphincters are relaxed, enabling blood flow through the wide-open capillaries and supply the surrounding tissue cell
- when the tissue has lower demands, the pre capillary sphincters contract, closing off the true capillaries and forcing blood flow straight from the met arteriole into the thoroughfare channel and venule
describe the structure of the major types of capillaries.
continuous: least permeable, most common (skin, muscle)
- tight junctions and occasional desmosomes hold together
- intercellular clefts
- pericytyes
fenestrated: large fenestrations (pores) increase permeability. occurs in areas of active absorption or filtration (kidney, intestine)
- tight junctions and intercellular clefts
- pores unique to this
sinusoid: most permeable, occurs in special locations (liver, bone marrow, spleen)
- usually fenestrated and have fewer cell junctions
- intercellular clefts open
external to endothelium cells in continuous capillaries, the delicate capillary is strengthened and stabilized by scattered _____, spider-shaped contractile stem cells whose thin processes form a widely spaced network around the capillary
perictyes
name the three vessels that arise from the aortic arch.
brachiocephalic trunk
left common carotid artery
left subclavian artery
what are the two branches of the brachiocephalic artery?
right common carotid artery
right subclavian artery
what regions does the brachiocephalic trunk supply blood to?
head, neck, upper extremities
what regions does the left common carotid artery supply blood to?
brain, face, neck
what regions does the left subclavian artery supply blood to?
left arm
the _____ _____, one of the greatest vessels leaving the heart, arises from the left ventricle and ascends for only about 5cm
ascending aorta
the only branches of the ascending aorta are the _______ and _____
right and left coronary arteries
arching posteriorly and to the left, the _____ _____ lies posterior to the manibrium of the sternum
aortic arch
the _____ _____, a fibrous remnant of a fetal artery called the ductus arterioles, connects the aortic arch and the pulmonary trunk
ligamentum anteriosum
continuing from the aortic arch, the _____ _____ runs posterior to the heart and inferiorly on the bodies of the thoracic and lumbar vertebrae
descending aorta
what are the 2 parts of the descending aorta?
thoracic aorta and abdominal aorta
the _____ _____ descends on the bodies of the thoracic vertebrae just to the left of the midline
thoracic vertebrae
the thoracic aorta passes through the diaphragm at the level of vertebrae T12 and enters the abdominal cavity as the _____ _____, which lies on the lumbar vertebral bodies in the midline
abdominal aorta
where does the descending aorta supply blood to?
pelvis and lower limbs
what organs are supplied by the Celiac trunk?
stomach
liver
gallbladder
pancreas
spleen
part of small intestine
the short, wide, unpaired _____ _____ supplies the vicar in the superior part of the abdominal cavity
celiac trunk
what organs are supplied by the suprarenal arteries?
adrenal glands on the superior poles of the kidney
what organs are supplied by the renal arteries?
kidneys
what organs are supplied by the common iliac arteries?
inferior part of the abdominal wall
pelvic organs
lower limbs
what regions do the internal jugular veins drain?
brain
the internal jugular vein receives blood from some deep veins of the face and neck, branches of the _____ and _____ _____ _____
fascial and superficial temporal veins
what regions do the external jugular veins drain?
posterior scalp
lateral scalp
some of the face
what regions do the subclavian vein drain?
brain
upper extremities
What vessels are formed by the juncture jugular and subclavian veins (there is a right and a left)?
internal jugular vein joins with the subclavian to make the brachiocephalic vein
external jugular is not accompanied
what vessels directly empty blood into the superior vena cava?
azygos vein
hemiazygos vein
accessory hemiazygos vein
the _____ _____, whose name means “unpaired,” ascends along the right or the center of the thoracic vertebral bodies.
azygous vein
the azygos vein receives all of the right _____ _____ _____, plus the subcostal vein
posterior intercostal veins
the _____ _____, which ascends on the left side of the vertebral column, corresponds to the inferior half of the azygos on the right
hemiazygos vein
the _____ _____ _____ can be thought of as a superior continuation of the hemizygos, receiving the fourth (or fifth) through the 8th left posterior intercostal veins; it also courses to the right o join the azygos
accessory hemiazygos vein
what organs (regions) are drained by the common iliac veins?
pelvic viscera
walls
gluteal region
perineum
what organs (regions) are drained by the lumbar veins?
posterior abdomen wall
what organs (regions) are drained by the renal veins?
kidneys
what organs (regions) are drained by the suprarenal veins?
adrenal glands
what organs (regions) are drained by the hepatic veins?
liver
what large vessel do each vein independently join?
inferior vena cava
what is the function of the hepatic portal system?
picks up digested nutrients from the stomach and intestines and delivers these nutrients to the liver for processing and storage
capillaries in the stomach and intestines receive the digested nutrients and then drain into the tributaries of the _____ _____ _____
hepatic portal vein
the right and left _____ _____ exit the liver superiorly and empty into the most superior part of the inferior vena cava
hepatic veins
