Fat

A fat body is usually found in a joint and is a deposition of fat that acts as a cushion against stress. Atherosclerosis is the term given to describe the depositing of fatty plagues in the lumina of the arteries and contributes to heart disease and strokes. Subcutaneous fat is a layer of the skin under the dermis which can store lipids, insulate and cushion the body, and regulate temperature.

A Vertebra

A typical vertebra has a drum-shaped "body" (centrum) that forms a thick, anterior portion of the bone. A longitudinal row of the bodies supports the weight of the head and trunk. The intervertebral disks, which separate joining vertebrae, are fastened to the roughened upper and lower surfaces of the bodies. These disks cushion and soften the forces created by walking and jumping, which might otherwise fracture the vertebrae or jar the brain. Each intervertebral disk is composed of a band of fibrous fibrocartilage (anulus fibrosus) that surrounds a gelatinous core, called the "nucleus pulposus." The bodies of adjacent vertebrae are joined on the front surfaces by "anterior ligaments" and on the back by "posterior ligaments." Projecting from the back of each body are two short stalks called "pedicles." They form the sides of the "vertebral foramen." Two plates (laminae) arise from the pedicles and fuse in the back to become "spinous process." The pedicles, laminae, and spinous process together complete a bony vertebral arch around the vertebral opening, through which the spinal cord passes. Between the pedicles and laminae of a typical vertebra is a "transverse process" that projects laterally and toward the back. Various ligaments and muscles are attached to the spinal process and the transverse process. Projecting upward and downward from each vertebral arch are "superior" and "inferior articulating processes." These processes bear cartilage-covered facets by which each vertebra is joined to the one above and the one below it. On the surfaces of the vertebral pedicles are notches that align to create openings, called "intervertebral foramina." These openings provide passageways for spinal nerves that proceed between joining vertebrae and connect to the spinal cord.

Ventral Root

The ventral root (motor root) of each spinal nerve consists of axons from motor neurons whose cell bodies are found within the gray matter of the spinal cord. A ventral root and a dorsal root unite to form a spinal nerve, which passes outward from the vertebral canal through an "intravertebral foramen" (bone opening). A "posterior branch" (posterior ramus) of each spinal nerve turns toward the to the posterior to innervate muscles and skin of the back. The main portion of the nerve, the "anterior branch" (anterior ramus), continues forward to supply muscles and skin on the front and sides of the trunk and limbs. The spinal nerves in the thoracic and lumbar regions have a fourth or "visceral branch," which is part of the autonomic nervous system.

Abdominal Aorta

The branches of the abdominal aorta may be divided into three sets: the visceral branches, which supply the organs in the abdomen, renals, testicles and ovaries; the parietal branches, which supply the diaphragm from below and the posterior abdominal walls; and the terminal branches, which descend to supply the organs of the pelvis, the pelvic wall and the paired common iliacs which supply the lower extremities.

Meninges

The spinal dura mater forms a tough, tubular dural sheath that extends into the vertebral canal and surrounds the spinal cord. There is no connection between the dural sheath and the vertebrae that form the canal there is a cavity called the epidural space which is highly vascular and contains loose and adipose tissue which forms a protective pad around the spinal cord. The arachnoid membrane is the middle of the meningeal layers and as its name implies, appears spider-like or more specifically, has the appearance of a spider web. The subarachnoid space, located between the arachnoid membrane and the pia mater is maintained by delicate, web-like strands that connect the arachnoid membrane and the pia mater. Cerebrospinal fluid is a clear, lymph-like fluid that forms a protective cushion around and within the central nervous system. Although produced in the ventricles of the brain, cerebrospinal fluid is found abundantly in the subarachnoid space where it buoys the central nervous system and protects it from injury. It is this fluid that is removed for analysis with lumbar puncture or spinal tap. The pia mater is a thin layer of modified loose connective tissue that follows the irregular contours of the brain and spinal cord. It is highly vascular and functions to support the vessels that nourish underlying cells of the brain and spinal cord.

Skull: Baby and Adult

The skull is the bony section of the head. The skull encases and protects the brain, houses the brain senses, provides attachments for muscles of the head and neck, and helps to form the first portions of the respiratory and digestive tracts. The skull rests on the first vertebra, which is called the "Atlas". At birth, the skull is large in comparison to the rest of the body, and a baby's skull is compressible. The "soft spots" in a baby's head harden and grow together until the bones meet and mesh like a jigsaw puzzle. The largest of the six main soft spots is a diamond-shaped area near the middle of the top of the skull. This is the last area to harden and close, usually at about the age of eighteen months. "Skullduggery" is some kind of trick or some unscrupulous behavior.

Dorsal and Ventral Roots

Each spinal nerve emerges from the cord by two short branches or roots, which are within the vertebral column. The dorsal or sensory root can be identified by the presence of an enlargement called the dorsal root ganglion which contains cell bodies of sensory neurons. The ventral root (motor root) of each spinal nerve has cell bodies located within the grey matter of the spinal cord. A ventral root and a dorsal root unite to form a spinal nerve which exits the vertebral canal through an opening called the intervertebral foramen.