Nervous Tissue and Lower Limb Anatomy

This set of vocabulary flashcards covers nervous tissue structure, neuron classification, bone markings of the lower limb, major lower limb joints, and the primary muscles and movements of the leg.

Neurons

Cells within nervous tissue that send electrical signals.

Neuroglia

Cells within nervous tissue that support, protect, and nourish neurons.

Nissl bodies

The granules of rough ER in neuron cytoplasm.

Oligodendrocytes

The cells that form myelin sheaths around axons of neurons in the Central Nervous System (CNS).

Axon

The part of the neuron that carries impulses AWAY from the cell body.

Cell body

The part of the neuron containing the nucleus and organelles.

Schwann cells

The cells that form myelin sheaths around axons of neurons in the Peripheral Nervous System (PNS).

Nodes of Ranvier

The gaps between Schwann cells along the axon.

Dendrites

The part of the neuron that receives impulses and sends them toward the cell body.

Synaptic end bulb

The ends of the axon containing vesicles; also known as synaptic knobs.

Myelin

Fatty layers that surround and electrically insulate the axon to speed up nerve impulses.

Axon hillock

The cone-shaped area where the axon leaves the cell body.

Synapse

The location where a neuron meets another neuron or an effector cell.

Neurotransmitter

The chemical message released by a neuron.

Synaptic vesicle

A membrane sac that stores neurotransmitters within the axon terminal.

Unipolar neurons

Neurons with one extension off the cell body; commonly found in the dorsal root ganglion of the spinal cord.

Bipolar neurons

Neurons with two extensions off the cell body; found in special sensory organs like the retina of the eye.

Multipolar neurons

Neurons with multiple extensions from the cell body; the most abundant type in the body.

Sensory (afferent) neurons

Neurons that transmit impulses from sensory receptors in the skin or organs TOWARD the Central Nervous System (CNS).

Interneurons

Neurons that conduct impulses WITHIN the CNS and integrate sensory input to predict proper motor output.

Motor (efferent) neurons

Neurons that carry impulses AWAY from the CNS to effectors like muscles, organs, or glands.

Linea aspera

A bone marking on the posterior view of the femur that serves as an insertion for the adductors of the thigh.

Tibial tuberosity

A bone marking on the anterior tibia that provides the distal attachment for the patellar ligament.

Fibula

The lower leg bone that stabilizes the ankle and supports muscles of the lower leg; includes the head and lateral malleolus.

Tarsals

A group of 7 bones of the foot including the medial cuneiform, intermediate cuneiform, lateral cuneiform, cuboid, navicular, talus, and calcaneus.

Coxal joint

The multiaxial ball-and-socket synovial joint formed between the acetabulum of the os coxa and the head of the femur.

Tibiofemoral joint

The biaxial modified hinge joint found between the tibia and the femur; contains menisci and ligaments.

Femoropatellar joint

The synovial plane joint between the femur and the patella that allows gliding.

Sartorius

A muscle that flexes and laterally rotates the hip joint and flexes the knee; originates at the anterior superior iliac spine.

Gracilis

The most superficial of the adductors; performs hip adduction, knee flexion, and knee internal rotation.

Tibialis anterior

An anterior lower limb muscle that performs dorsiflexion by pulling the foot toward the shin.

Gastrocnemius

A posterior lower limb muscle involved in plantarflexion (standing on toes) and active during running and jumping.

Gluteus maximus

The main extensor of the hip; originates from the ilium, sacrum, and coccyx and inserts on the gluteal tuberosity and iliotibial band.

Tensor fasciae latae

An anterior/lateral muscle that performs hip flexion and hip abduction.

Dorsiflexion

The movement of raising the toes upward toward the shin.

Plantarflexion

The movement of standing on toes or pointing the foot downward.

Origin

The attachment point of a muscle that generally remains stationary during contraction.

Insertion

The attachment point of a muscle that moves toward the origin when the muscle contracts.