Kin 223 Lab 7 Guide

epimysium

A layer of dense, irregular connective tissue surrounding a skeletal muscle

perimysium

Fibrous sheath enveloping each of the fascicles of skeletal muscle fibers

endomysium

Areolar connective tissue layer surrounding a muscle cell or fiber

tendon

thick cord of dense regular connective tissue that connects muscle to bone

skeletal muscle

vascularized by an extensive network of blood vessels

• extends through epimysium and perimysium to reach endomysium

• innervated by motor neurons to control contraction

• voluntary

muscle fascicle

bundle of muscle fibers or axons

muscle fiber

a skeletal muscle cell

• called this because of their length

motor unit

One motor neuron and all the skeletal muscle fibers it innervates

motor unit: striations

motor unit: axons

axon of each motor neuron divides into many individual branches to innervate numerous skeletal muscle fibers

spinal cord

nerve cells transmit nerve signals from brain or spinal cord to control skeletal muscle activity

neuromuscular junction

specific location where skeletal muscle fiber is innervated by a motor neuron

• each fiber has one

neuromuscular junction: synaptic cleft

narrow (30 nm) fluid filled space separating the synaptic knob and motor end plate

• contains AChE, breaks down ACh molecule

neuromuscular junction: synaptic knob

expanded tip of axon

• houses numerous synaptic vesicles filled with ACh

• Ca2+ pumps embedded in membrane, prior to signal these pumps establish a Ca2+ concentration gradient with more outside than in

• voltage gated Ca2+ channels allow flow of Ca down gradient from interstitial fluid to knob

neuromuscular junction: motor end plate

specialized region of sarcolemma of skeletal muscle fiber

• lots of ACh receptors which allows Na+ entry into muscle fiber and a K+ to exit upon binding of ACh

comparison of muscle types: smooth muscle

comparison of muscle types: cardiac muscle

comparison of muscle types: skeletal muscle

facial expression: epicranius

facial expression: orbicularis oculi

facial expression: orbicularis oris

facial expression: zygomaticus major

facial expression: zygomaticus minor

facial expression: risorius

facial expression: mentalis

mastication (chewing): masseter

mastication (chewing): temporalis

mastication (chewing): lateral pterygoid

mastication (chewing): medial pterygoid

mastication (chewing): buccinator

move head and neck: sternocleidomastoid

move head and neck: scalene muscle

vertebral column: erector spinae iliocostalis group

vertebral column: erector spinae longissimus group

vertebral column: erector spinae spinalis group

respiration: external intercostals

respiration: internal intercostals

respiration: diaphragm

abdominal wall: rectus abdominus

abdominal wall: external oblique

abdominal wall: internal oblique

abdominal wall: transversus abdominus

pectoral girdle & upper limb: pectoralis major

pectoral girdle & upper limb: pectoralis minor

pectoral girdle & upper limb: deltoid

pectoral girdle & upper limb: subscapularis

pectoral girdle & upper limb: levator scapulae

pectoral girdle & upper limb: trapezius

pectoral girdle & upper limb: latissimus dorsi

pectoral girdle & upper limb: rhomboid major

pectoral girdle & upper limb: rhomboid minor

pectoral girdle & upper limb: serratus anterior

move the arm at the glenohumeral joint: latissimus dorsi

move the arm at the glenohumeral joint: pectoralis major

move the arm at the glenohumeral joint: deltoid

move the arm at the glenohumeral joint: coracobrachialis

move the arm at the glenohumeral joint: teres major

move the arm at the glenohumeral joint: subscapularis

move the arm at the glenohumeral joint: supraspinatus

move the arm at the glenohumeral joint: infraspinatus

move the arm at the glenohumeral joint: teres minor

move the forearm at the elbow joint: biceps brachii long head

move the forearm at the elbow joint: biceps brachii short head

move the forearm at the elbow joint: brachialis

move the forearm at the elbow joint: brachioradialis

move the forearm at the elbow joint: triceps brachii lateral head

move the forearm at the elbow joint: triceps brachii long head

move the forearm at the elbow joint: triceps brachii medial head

move the forearm at the elbow joint: anconeus

pronate and supinate the forearm: supinator

pronate and supinate the forearm: pronator teres