Units of the Body in Speech and Hearing Science: Cells, Tissues, Organs, and Systems

Cell

smallest unit of living matter

Tissue

groups of cells with common function

Histology

a branch of anatomy dealing with the microscopic structure of tissue

Organ

two or more tissues with common function (e.g., heart, lung)

System

two or more organs combine in such a manner as to exhibit functional unity.

Connective Tissue

a type of tissue that supports, binds together, and protects tissues and organs of the body.

Muscle Tissue

a type of tissue that is responsible for the movement of the body and its parts.

Nerve Tissue

a type of tissue that transmits impulses throughout the body.

Epithelial Tissue

a type of tissue that covers the body surfaces and lines cavities and organs.

Soft Connective Tissue

includes loose and dense connective tissues, important for structural support.

Loose Connective Tissue

areolar (more delicate fibrous tissue found just beneath skin) and adipose (fat tissue).

Dense Connective Tissue

resisting stretch longitudinally (e.g., tendons, aponeuroses, ligaments).

Irregular Dense Connective Tissue

resisting stretch in all directions (e.g., dermis, periosteum, fascia).

Lymphatic Tissue

includes tonsils and adenoids.

Cartilage

developmentally, most of skeleton are cartilaginous in fetus; types include hyaline, fibrous, and elastic.

Bone (osseous tissue)

includes dense/compact part (outer part of bone) and spongy/cancellous part (interior part of bone).

Axial Skeleton

includes trunk and head.

Appendicular Skeleton

includes limbs and immediately attached structures.

Fibrous Joint

immovable joints (e.g., joints in the skull).

Cartilaginous Joint

slightly movable joints (e.g., intervertebral discs, pubic symphysis).

Synovial Joint

freely moving joints, most common type in the body.

Ball and Socket Joint

great motion in all directions, many axes of movement (e.g., hip joint).

Hinge Joint

motion in only one plane (e.g., elbow, knee).

Pivot Joint

rotation along axis (e.g., atlas and axis).

Saddle Joint

all motion except rotation (e.g., thumb).

Condyloid Joint

two types of motion at right angle, no neck rotation or twisting (e.g., wrist).

Gliding Joint

sliding movement, least movement (e.g., vertebral articular processes).