Unit 3 Study Guide-4 - Summary Anatomy and Physiology PDF

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BIO 231 Unit 3 Study Guide Muscle and Muscle Tissue  Compare and contrast the three basic types of muscle tissue as discussed in class regarding tissue location, cell shape and size and regulation of contraction. o

o

Skeletal: 

Long and striated



Multi nucleated



Voluntary

Cardiac o

Branched

o

Uninucleated

o

Striated

o

Found in the heart

o

Intercalated discs

o

Gap junctions that communicate and desmosomes and anchor cells

o

Involuntary

Smooth Muscles o

Involuntary and not striated

o

In organs and what not

o

Spindle shaped

 Know the characteristics of skeletal muscle as described in Table 9.3 from the text.  What prefixes are used describing muscle? Myo, Mys, sarco  List four main functions of muscle tissue, as well as the additional functions described in class. o

Heat generation

o

Joint stabilization

o

Bone movement

o

Maintains body posture

o

Protects organs

o

Goosebumps

 Know the definitions of an agonist, antagonist and synergist and give an example of each during flexion of the elbow. o

Antagonistic- opposes movers (triceps)

o

Agonist- movers (biceps)

o

Synergists- help movers and eliminates undesirable and unnecessary movements (radiolarians, coracobrachialis)

 Know the various ways muscles are named o

Location

o

Shape

o

Size

o

Directions of muscles fibers

o

Number of origins

o

Location of attachments

o

Muscles action

 Describe the gross structure of a skeletal muscle including the muscle shapes based on the fascicle arrangement and surrounding connective tissue. o

Convergent- all come together into a common tendon

o

Circular- fascicles are in concentric rings around a body opening.

o

Uipennent- tendons run through the body and fibers come off the side

o

Bipennet- fibers come off both sides

o

Multipennent- many pennant muscles together

o

Epimysium surrounds the muscle that is made up off fascicles that is surrounded by Perimysium which is made of muscle fibers that are surrounded by endomysium, muscle fibers are made of myofibril

 Be able to discuss what occurs at the neuromuscular junction. o

An action potential is received from the t tubule that causes opens calcium gated channels (voltage gated) calcium causes the vesicles containing Ach to fuss and they exit the presynaptic cell via exocytosis, they diffuse across the cleft, and bind to receptors that cause Na (in)/K(out) channels to open and depolarization to occur at the sarcolemma. The effects of Ach are terminated by either diffusion away or acetocholineresterase.

 Describe the microscopic structure and functional roles of the sarcolemma, myofibrils, myofilaments, sarcoplasmic reticulum, and T tubules of skeletal muscle fibers. o

Sarcolemma- the plasma membrane

o

Myofibrils are densely packed rod like elements that have dark and light bands that give the muscle striations.

o

Myofilaments: filaments of myofibrils- actin and myosin

o

Sarcoplasmic reticulum: the endoplasmic reticulum that stores and regulated intracellular Ca levels

o

T-tubules: continuations of the sarcolemma, they are part of the terminal cistern to for triads that encircle the sarcomere

 What is the functional unit of a muscle fiber. o

The sarcomere that contains the thin and thick filaments

 Be able to draw a sarcomere with A bands, I bands, Z discs, H zones and M lines.

 Describe the structure of the thick and thin filaments including troponin, tropomyosin, actin and myosin. What is titan and what does it do? o

Thick filaments are made of myosin tails and myosin heads (proteins) made for binding

o

Thin filaments are made of twisted double strands actin, and troponin and tropomyosin which are regulatory proteins

o

Elastic filaments: composes of titan and this allows for there to be recoil after stretch, attached to thick filaments and resist excessive stretch

 Describe the sliding filament model of muscle contraction. o

The z discs move closer together as the myosin and actin slide past each other during contraction, either is actually shortening they are simply overlapping more.

 Describe how an action potential is generated. What is an end plate potential? How is the action potential propagated? o

End plate potential is the local depolarization that occurs at the NMJ

o

The action potential is propagated by the Nicotenic receptors that open and sodium floods in and the threshold is reached and once initiated it is unstoppable

 Describe a muscle fiber action potential and be able to graph the change in membrane potential over time. o

Typical membrane potential vs time

o

Depolarization, repolarization, hyperpolarization

 Follow the events of excitation-contraction coupling that lead to cross bridge activity. o

The action potential propagates along the sarcolemma and down the t tubules

o

Calcium ions are released

o

Calcium binds to troponin (this changed shape) and removes the blocking action of tropomyosin

o

Contraction begins as myosin binds to actin and forms a cross bridge and contacts

 Be able to describe the events that occur in the cross bridge cycle? o

Energized myosin head attaches to an actin myofilament

o

The power stroke occurs when ADP and P are releases from the myosin head, the head pivots and pulls the actin towards the m line

o

The cross bridge is detached when ATP binds to the myosin head

o

If ATP is hydrolysis to ADP and P then the myosin head returns to the cocked position.

 What is rigor mortis and what causes it? o

Stiffness in death

o

ATP causes the cross bridge to detach and there is not ATP in death so it causes the muscles to be contracted after 3-4 of death.

 What is botulism, what causes it, and what area of the NMJ does it affect? o

A type of food poisoning from a bacteria

o

Water and food can carry it

o

It blocks the release of Ach

o

Causes flaccid paralysis

 Define motor unit and muscle twitch, and describe the events occurring during the three phases of a muscle twitch. o

Motor unit is a motor neuron and the muscles it innervates

o

Muscle twitch is the motor units response to a single action potential of its motor neuron 

Latent period (refractory period)



Period of contraction



Period of relaxation

 Explain how smooth, graded contractions of a skeletal muscle are produced. What is fused and unfused tetany. o

Stimuli is given quickly enough that the muscle reaches max tension

o

Fused- complete contraction

o

Unfused tenany- the muscle does not completely relax

 Define muscle tension and load. o

Tension is the force exerted on a contracting muscle on an object

o

Load is the opposing force exerted on the muscle by the weight of the object

 What 4 factors affect the force of muscle contraction? o

Size

o

Frequency of stimuli

o

Stretch of muscle and sarcomere

o

How many muscle fibers are recruited

 How does recruitment occur in the lab and in the body? What is the benefit of recruitment? o

Lab: delivering stronger and stronger stimulus to muscle

o

In the body: activation of increasingly larger numbers of motor units

o

They are recruited in size principle, so they are need bases. Small to large, they are also asynchronous to prevent fatigue.

 Differentiate between isometric and isotonic contractions. o

Isometric- same length

o

Isotonic- changes the length 

Concentric-shortens



Eccentric- lengths

 What is hypertrophy and atrophy. What changes occur in the muscle fibers? o

o

Hypertrophy- huge muscles 

Increase size of muscle fibers



More myofibrils and myofilaments



More mitochondria



More blood supply

Atrophy- lack of muscles 

Loss of use and proteins



May result in cell loss



Never regain those cells

 Describe three ways in which ATP is regenerated during skeletal muscle contraction. o

Used in the Na/K ATPase in the sarcolemma

o

Myosin detachment from actin

o

Calcium retuning to the SR

 Describe three types of skeletal muscle fibers and explain the relative value of each type. o

o

o

Slow Oxidative 

Slow contraction



High myoglobin supply



Aerobic with oxygen



Slow to fatigue



Endurance activity

Fast Glycolytic 

Lighter and have low myoglobin content



Fast to contract



Anaerobic



Fatigue easier



Short and powerful movements

Fast Oxidative, Glycolytic. 

Have high contraction speed and have a high myoglobin content



Pink in color



Can be glycolytic but with training can be oxidative



Intermediate range of fatigue

 What are the adaptations that occur with aerobic exercise? o

Leads to increases muscle capillaries

o

Myoglobin synthesis

 Understand the concepts presented in the malignant hyperthermia case study. o

Calcium channels (RYR) are quick to open but slow to close so there is a constant contraction which causes person to overheat. Also have a high CO2 release because aerobic process

The Special Senses  What are the special senses, and what differentiates them from general senses? o

They are highly localized in head with special sensory cells

o

Vision

o

Smell

o

Hearing

o

Taste

o

Equilibrium

 Describe the structure and function of accessory eye structures including eyelids, lacrimal apparatus and extraocular muscles. o

Eyelids: lubricate and protect eye

o

TARSAL glands are modified sebaceous glands that are on water line (oily secretion lubricated eye and eye lid)

o

Lacrimal glands secrete tears which have water, antibacterial and lysosomes in them

o

Extraocular Muscles- muscles that cause eye movement

o

Rectus: 

Lateral Abduces out



Medial Oculomotor in



Inferior Oculomotor down



Superior Oculomotor up



LR3SO4



Superior Oblique (trochlear)



Inferior Oblique (oculomotor) Rotate eyes

 How do meibomian glands and lacrimal glands differ? o

Lacrimal is tears and a large gland

o

Meibomain or tarsal glands are sebaceous glands and there are many small ones

 Know the pathway tears take from the lacrimal gland into the nose. o

Lacrimal gland

o

Across eye medially

o

Lacrimal punctum

o

Lacrimal canaliculus

o

Lacrimal Sac

o

Nasolacrimal duct

 Know the parts of the fibrous, vascular and retinal layers and their functions as discussed in class. o

Fibrous: Sclera and Cornea

o

Sclera is the white part that gives eye structure and protects

o

Cornea is a transparent collagen that is stratified squamous and protects the eye

o

Function: bends light as it enters into the eye and has pain receptors that aid in blinking and crying 

Epithelium



Stroma- 60-70 layers of collagen fibers



o



Equal in diameter and equidistance apart



Avascular



Clear

Endothelium- one cell layer thick 

Leaky tight junctions allow for aqueous humor to be permeable



It exports ions and water from stoma to aqueous humor



This allows it to be in state of relative dehydration



Maintains the transparence

Vascular Layer 

Choroid- supplies nutrients to eyes through blood vessels



Brown color absorbs light to avoid scattering of light



Ciliary body- smooth muscles that control lens shape



Iris- color portion of eye, changed the pupil shape

o

Retina

o

Outer pigment layer 

Single layer think



Absorbs light and prevents its scattering

o

Inner Neutral layer

o

Transparent 

Contains 

Photoreceptors



Bipolar cells



Ganglion cells

 What is the optic disc and why does it produce a blind spot? o

Optic disc is where the optic nerve leaves the eye

o

Lacks photoreceptors

 What is a penetrating keratoplasty? o

When the cornea becomes cloudy and you have a cornea transplant

 Cataract surgery?



o

Lens becomes clouded

o

Crystalline proteins clump

o

Must break up lens and put in a new acrylic one

LASIK?

 Outline the causes and consequences of cataracts. o

Aging

o

Diabetes

o

Heavy smoking

o

And intense sun exposure

o

You have very clouded vision most are blind

 Trace the pathway of light through the eye to the retina, and explain how light is focused for distant and close vision. o

Cornea-aqueous humor-lens-vitreous humor-ganglia-bipolar cellsphotoreceptors

o

Close vision the parasympathetic division kicks and and causes the ciliary muscles to contact and the lens to bulge

o

Far vision the sympathetic division kicks in and the ciliary muscles loosen causing the lens to be flat.

 What is emmetropia (normal eye) , hyperopia (farsighted- the eye is too short so you need a convex lens to focus), myopia (nearsighted, the eye is too long and you need a convex lens to focus) , presbyopia (the loss of accommodation over time, comes with old age)  Compare and contrast rods and cones in structure and function.

o

Rods look like rods and are for night vision, they are sensitive to light and contain a single grey pigment. Mostly in peripheral retina

o

Cones are the color pigment they are not very sensitive need bright light for activation

o

Central retina

 What sort of visual field defects would occur in lesions along different areas of the visual pathway?  Describe the events that convert light into a neural signal. o

Light comes in and travels through Ganglion, bi polar cells and then hits neurotransmitters (rods

 What is dark adaptation? Cones stop function in the dark and rods are still turned off from being in the light o 

After a while the pupils dilate and you can see

Color blindness? o

Missing cones...