HW #3

Place the events involved in muscle contraction in the correct order.

1. A nerve impulse causes ACh release at a neuromuscular junction. 2. ACh binds receptors on the motor end plate, initiating a muscle impulse. 3. Calcium ions bind to troponin, causing tropomyosin to move and expose active sites. 4. Myosin heads attach to actin and form crossbridges. 5. A cyclic "attach, pivot, detach, return" event occurs. 6. Calcium ions are moved back into the sarcoplasmic reticulum by ATP-driven pumps. 7. Myofilaments passively return to their original state.

Place the organizational level of muscle tissue in order, beginning with muscle and ending with the smallest component.

1. Muscle 2. Fascicle 3. Muscle Fiber 4. Myofibril 5. Myofilament

Place the blood vessel tunics in order from most external to most internal.

1. Tunica externa 2. Tunica media 3. Tunica intima

Check all that are proteins of thin filaments.

Actin Troponin Tropomyosin

Central nervous system

Consists of the brain and spinal cord

Match the vein with its companion vessel. Elastic Artery Muscular Artery Arteriole

Elastic Artery: Large vein Muscular Artery: Medium sized vein Arteriole: Venule

Match the connective tissue with the component of skeletal muscle tissue that it surrounds. Epimysium Perimysium Endomysium

Epimysium: Surrounds the whole skeletal muscle Perimysium: Surrounds the fascicles Endomysium: Surrounds each muscle fiber

Peripheral nervous system

Includes cranial and spinal nerves

For muscles moving the axial skeleton, the less mobile attachment of a muscle is typically the ___________ attachment.

Inferior

Autonomic motor

Innervates cardiac and smooth muscle

Somatic motor

Innervates skeletal muscles

Somatic sensory

Receives information from skin

Visceral sensory

Receives information from the intestines

At the ends of muscles, the connective tissues merge to form a __________, which attaches the muscle to other structures.

Tendon

How do veins return blood to the heart? Select all that apply.

Veins have one-way valves that prevent backflow in the limbs. The contraction of skeletal muscles helps move blood toward the heart.

The type of muscles in which the fascicles are at an oblique angle to the tendon, and the muscle fibers resemble a large feather is called

pennate

Another term for the __________ system is the afferent nervous system.

sensory

The ___________ nervous system transmits information from receptors to the CNS, while the ___________ nervous system transmits information from the CNS to the rest of the body.

sensory; motor

The "voluntary" nervous system component of the motor nervous system is the ____________ motor subdivision.

somatic

The component of a muscle fiber that quickly transports a muscle impulse from the sarcolemma throughout the entire muscle fiber is called the

transverse tubule (T-tubule).

Capillaries have only a

tunica intima.