Muscle Tissue Types, Major Skeletal Muscles, and Divisions of the Nervous System

Flashcards reviewing the histology of muscle types, origins, insertions, and actions of selected muscles, and the organizational divisions of the nervous system.

What are the shape, size, striation, branching, nucleation, and nervous control characteristics of skeletal muscle?

Skeletal muscle is cylindrical, very long (up to $30\,\text{cm}$), striated, non-branched (no), multinucleate (yes), and controlled by the Somatic NS (voluntary).

What are the shape, size, striation, branching, nucleation, and nervous control characteristics of cardiac muscle?

Cardiac muscle is complex, short ($50\text{--}100\,\mu\text{m}$), striated, branched (yes), generally not multinucleate (no), and controlled by the Autonomic NS (involuntary).

What are the shape, size, striation, branching, nucleation, and nervous control characteristics of smooth muscle?

Smooth muscle is spindle shaped, short ($30\text{--}200\,\mu\text{m}$), non-striated (no), non-branched (no), not multinucleate (no), and controlled by the Autonomic NS (involuntary).

What are the origin, insertion, and primary action of the rectus femoris muscle?

Origin: Anterior inferior iliac spine, margin of acetabulum. Insertion: Tibial tuberosity, patella. Action: Extends knee.

What are the origins, insertions, and actions of the vastus medialis and vastus lateralis muscles?

Vastus medialis originates at the linea aspera of femur; vastus lateralis originates at the greater trochanter and linea aspera of femur. Both insert at the tibial tuberosity and patella, and both extend the knee.

What are the origin, insertion, and primary actions of the biceps femoris muscle?

Origin: Ischial tuberosity, linea aspera of femur. Insertion: Head of fibula, lateral condyle of tibia. Action: Flexes knee, extends thigh.

What are the origins, insertions, and actions of the adductor longus and adductor magnus muscles?

Adductor longus originates at the pubis; adductor magnus originates at the pubis and ischial tuberosity. Both insert on the linea aspera of the femur and act to adduct the thigh.

What are the origin, insertion, and primary action of the gastrocnemius muscle?

Origin: Condyles of femur. Insertion: Calcaneus. Action: Plantar flexion.

What are the origin, insertion, and primary actions of the fibularis longus muscle?

Origin: Head and lateral surface of fibula. Insertion: Medial cuneiform, metatarsal I. Action: Plantar flexion, foot eversion.

What are the origin, insertion, and primary action of the masseter muscle?

Origin: Zygomatic arch. Insertion: Angle of mandible. Action: Elevates mandible.

What are the origin, insertion, and actions of the sternocleidomastoid muscle?

Origin: Manubrium of sternum, medial clavicle. Insertion: Mastoid process of temporal bone. Action: Neck flexion, head rotation, and respiration.

What are the origin, insertion, and action of the pectoralis minor muscle?

Origin: Ribs 3-5. Insertion: Coracoid process of scapula. Action: Pulls scapula forward and inferior.

What are the origin, insertion, and actions of the deltoid muscle?

Origin: Lateral clavicle, acromion and spine of scapula. Insertion: Deltoid tuberosity of humerus. Action: Arm abduction and rotation.

What are the origin, insertion, and actions of the biceps brachii muscle?

Origin: Coracoid process of scapula (short head), margin of glenoid cavity (long head). Insertion: Radial tuberosity. Action: Supination of forearm, flexion of elbow.

What are the origin, insertion, and action of the rectus abdominis muscle?

Origin: Pubis. Insertion: Xiphoid process, costal cartilages 5-7. Action: Flexion of lumbar vertebral column.

What are the two major divisions of the nervous system and their primary components?

The Central Nervous System (CNS), consisting of the brain and spinal cord, and the Peripheral Nervous System (PNS), consisting of nerves and ganglia located outside the CNS.

What are the two main functional divisions of the Peripheral Nervous System (PNS) and their respective subcomponents?

The Sensory Division, which includes Visceral (autonomic) Sensory and Somatic (skeletal muscle) Sensory, and the Motor Division, which includes Visceral (autonomic) Motor and Somatic (skeletal muscle) Motor.

Into what two branches is the Visceral (autonomic) Motor division divided?

The Sympathetic Division and the Parasympathetic Division.

How is the Somatic Nervous System characterized in terms of inputs, outputs, and voluntary control?

It involves sensory input from skeletal muscles and motor output to skeletal muscles; it is primarily voluntary (consciously controlled), except for involuntary skeletal muscle reflexes.

What is the primary role and control nature of the Visceral (Autonomic) System?

It monitors and coordinates the sensory and motor activities of most internal organs and tissues to maintain a homeostatic internal environment; it is not consciously controlled and adjustments are not usually noticed.

How do sensory and motor pathways differ between the somatic and visceral divisions?

Both somatic and visceral divisions receive and send sensory (afferent) information to the CNS along the same pathways, but their motor (efferent) responses from the CNS to effectors travel along separate pathways.