ANSC 3070 - Exam 4

Skeletal Muscles: slides 1-45 // Special Senses: slides 46- Quiz 8: slides 1-

Where is smooth muscle found?

Reproductive and GI tracts and blood vessels larger than capillaries

Smooth muscle is (straited/nonstriated) and (voluntary/involuntary).

Nonstriated, involuntary

What cells make up smooth muscle?

Fusiform cells with tapered ends

How do actin and myosin interact in smooth muscle?

They criss-cross

How is smooth muscle innervated?

By the autonomic nervous system and hormones

Does smooth muscle contain a neuromuscular junction?

No

How does smooth muscle neurotransmit?

Pinocytosis

Smooth muscle does not contain T tubules for cell communication; instead, it contains this:

Gap junctions with connexon molecules

How does smooth muscle intake calcium?

Caveolae invaginations allow calcium to enter the cell from the interstitial space

How does contraction of smooth muscle compare to skeletal muscle?

Takes longer to develop but lasts longer

What is the calcium binding protein in smooth muscle?

Calmodulin

What is single-unit smooth muscle?

ANS innervates a single cell and action potential spreads to neighboring cells so the whole bundle contracts together

What is multi-unit smooth muscle?

ANS innervates individual cells allowing for fine control

What type of smooth muscle makes up the majority in the body?

Single-unit

What does the longitudinal layer of single-unit smooth muscle do?

Contraction dilates and shortens the organ

What does the circular layer of single-unit smooth muscle do?

Contraction constricts the lumen of the organ

Cardiac muscle is (striated/unstriated) and (voluntary/involuntary).

Striated, involuntary

Cardiac muscle is autorhythmic. What does this mean?

Can contract without nerve stimulation

What direction(s) do cardiac muscle fibers contract?

Multiple

How are cardiac muscle cells connected?

At intercalated discs containing desmosomes and gap junctions

What is an agonist?

Prime mover

What is an antagonist?

Opposes agonist

What is a synergist?

Assists agonist

What is a fixator?

Stabilizes joints

What is an intrinsic skeletal muscle?

Lies in one area

What is an extrinsic skeletal muscle?

Runs from one area to another

What are the three intrinsic muscles of facial expression and their functions?

What are the three intrinsic muscles of facial expression and their functions?

Temporalis - close jaw, strongest head mm

Digastricus - open jaw

Masseter - close jaw, lateral to mandible

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What are the two muscles of the vertebral column and their functions?

Epaxial - superficial, activates during tail wagging

Hypaxial - deep, activates during hindlimb extension

What are the two muscles of the thorax and their functions?

External intercostal - superficial, expand for inhalation

Internal intercostal - deep, shrink for exhalation

What is the diaphragm?

Main muscle of inhalation, separates thorax and abdomen

What are the four abdominal muscles in order from most superficial → deepest?

External abdominal oblique → Internal abdominal oblique → Transversus abdominus → Rectus abdominus

What are the four extrinsic muscles of the forelimb and their functions?

Trapezius - raise shoulder, pull forelimb forward

Pectoral - adduction

Latissimus dorsi - pull forelimb backward

Brachiocephalicus - pull forelimb forward

What are the two intrinsic muscles of the forelimb and their functions?

Supraspinatus and infraspinatus - abduction

What are the three muscles of the elbow and their functions?

Triceps brachii - extend elbow

Biceps brachii - flex elbow

Brachialis - flex elbow

What are the muscles of the carpus and digits?

2 carpal extensors, 2 digital extensors, 2 carpal flexors, 2 digital flexors

Where do the muscles of the originate and insert?

Pelvic girdle; femur

What is the function of the 3 gluteal muscles?

Extend hip joint

What are the 3 muscles of the hamstring group?

Biceps femoris, semitendinosus, semimembranosus

What is the function of the hamstring muscles?

Propel and extend hindlimb backwards

How many mucles are in the quadriceps femoris group?

4

What are the 3 muscles of the hindlimb that don’t belong to any group?

Pectineus, sartorious, gracilis

What are the 2 muscles of the lower hindlimb and their functions?

Gastrocnemius - extend hock, flex stifle

Achilles tendon - inserts on hock

What is the major muscle of the hock and its function?

Anterior tibialis - flexes hock

What are the 5 digital muscles?

3 extensors, 2 flexors

What are extensions of the CNS that help monitor the inside and outside of the animal?

Senses

What are the 4 stimuli that sensory receptors are sensitive to?

Mechanical, thermal, electromagnetic, chemical

How many senses are there?

5 general, 4 special

What are the 5 general senses?

Visceral, tactile, temperature, pain, propioception

What are vague, poorly localized sensations that facilitate hunger, thirts, and hollow organ fullness?

Visceral

What sense operates at an almost unconscious level unless there is abrupt, severe, or changing contact?

Tactile (touch)

What sense uses superificial and central receptors to transmit info to the CNS?

Temperature

Where are central temperature receptors located?

Hypothalamus

What sense has simple, free nerve endings everywhere exepct the brain?

Pain

What are pain receptors called?

Nocieceptors

What is the most common sensory receptor in the body?

Pain

What is an animal’s instinct in regards to pain?

Mask it

What sense involves sense of body movement and position?

Propioception

What is the current approach on pain management in veterinary medicine?

Anticipation and prevention

What body system mediates pain-induced stress responses?

Endocrine

What 3 hormones are increased in result of pain?

Cortisol, catecholamines, inflammatory mediators

Does pain cause the nervous system to become more or less sensitive?

More

What type of pain is the normal response to tissue damage and involves inflammation?

Adaptive

What type of pain results in spinal cord and brain changes if adaptive pain is not managed?

Maladaptive

What is pain experienced in areas unrelated to the original source long after the original injury is healed?

Wind-up pain

What is the nervous system receptor that can bind to aspartate or glutamate to create chronic pain?

NMDA

What is the term for experiencing both adaptive and maladaptive pain?

Onychectomy