GA Intro

• Anatomy is the science of the structure and

function of the body.

• Clinical anatomy is the study of the macroscopic

structure and function of the body as it relates to the

practice of medicine and other health sciences.

• Basic anatomy is the study of the minimal amount of

anatomy consistent with the understanding of the

overall structure and function of the body.

Skin

• Layers of the Skin:

• Epidermis: Outer, protective layer

• Dermis: Middle layer containing blood vessels, nerves,

and glands

• Superficial fascia (hypodermis or subcutaneous

tissue): Deepest layer, composed of fat and connective

tissue

• Appendages of the skin:

• Nails: keratinized plates on the dorsal surfaces of the tips

of the fingers and toes

• Hair follicles: invaginations of the epidermis into the

dermis

• Sebaceous glands: pour their secretion, the sebum, onto

the shafts of the hairs as they pass up through the necks of

the follicles. They are situated on the sloping undersurface

of the follicles and lie within the dermis

• Sweat glands: are long, spiral, tubular glands distributed

over the surface of the body, except on the red margins of

the lips, the nail beds, and the glans penis and clitoris

• Types of Fasciae:

• Superficial Fascia (hypodermis or subcutaneous

tissue): Lies just below the skin; contains adipose (fat)

and connective tissue

• Deep Fascia: Dense connective tissue that surrounds

muscles, bones, nerves, and blood vessels

• In the region of joints, the deep fascia may be considerably thickened

to form restraining bands called retinacula. Their function is to hold

underlying tendons in position or to serve as pulleys around which the

tendons may move.

• Skeletal Muscle: Voluntary muscles attached to bones;

responsible for movement

• Cardiac Muscle: Involuntary muscle found in the heart;

responsible for pumping blood

• Smooth Muscle: Involuntary muscle found in walls of

internal organs; responsible for various functions such as

digestion

Skeletal Muscle

• Attachments:

• Origin: moves the least

• Insertion: moves the most

• Parts:

• Belly: fleshy part of the muscle

• Tendons: cords of fibrous tissue that attaches the ends of a muscle

to bones, cartilage, or ligaments

• Aponeurosis: a thin but strong sheet of fibrous tissue that attaches

flattened muscles

• Raphe: is an interdigitation of the tendinous ends of fibers of flat

muscls

Joints

• Types of Joints:

• Fibrous Joints: Immovable joints connected by fibrous

tissue (e.g., sutures in the skull)

• Cartilaginous Joints: Slightly movable joints connected by

cartilage (e.g., intervertebral discs)

• Synovial Joints: Freely movable joints with a synovial cavity

(e.g., knee, shoulder)

Stability of Joints

• Articular Surfaces: bone shape plays an important role in

joint stability

• Ligaments:

• Fibrous ligaments prevent excessive movement in a joint, but if the

stress is continued for an excessively long period, then fibrous

ligaments stretch.

• Elastic ligaments, conversely, return to their original length after

stretching.

• Muscle Tone: Without the action of muscles, very little force

would be required to dislocate this joint.

Nerve Supply of Joints

• The capsule and ligaments receive an abundant

sensory nerve supply. A sensory nerve supplying a

joint also supplies the muscles moving the joint and

the skin overlying the insertions of these muscles, a

fact that has been codified as Hilton’s law

Ligaments, Bursae, Synovial Sheath

• Ligaments:

• Connect bone to bone

• Provide joint stability and limit movement

•Bursae:

• Fluid-filled sacs that reduce friction between moving

structures

• Located between bones and tendons/muscles

• Synovial Sheath:

• Double-layered tubular structure surrounding tendons

• Facilitates smooth tendon movement

• Arteries: Carry oxygenated blood away from the heart

• Veins: Carry deoxygenated blood toward the heart

• Capillaries: Tiny blood vessels where exchange of

substances occurs between blood and tissues

Lymphatic Tissues: a type of connective tissue that

• contains large numbers of lymphocytes.

• Lymph Vessels: Transport lymph, a fluid containing white

blood cells and other immune components

• Lymph Nodes: Filter lymph and house lymphocytes that

fight infection

• Lymph: Fluid that circulates through the lymphatic system

•Central Nervous System:

• composed of large numbers of nerve cells and their

processes, supported by specialized tissue called

neuroglia

• Neuron is the term given to the nerve cell and all its

processes

• Dendrites: the short processes of the cell body

• Axon: the longest process of the cell body

• Interior:

• Gray matter consists of nerve cells embedded in neuroglia.

• White matter consists of nerve fibers (axons) embedded in

neuroglia.

• Peripheral Nervous System:

• Cranial Nerves: 12 pairs of nerves that leave the brain and

pass through foramina in the skull

• Spinal Nerves: 31 pairs of nerves leave the spinal cord and

pass through intervertebral foramina in the vertebral

column

• 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal

• In the upper cervical region, the spinal nerve roots are short and

run almost horizontally, but the roots of the lumbar and sacral

nerves below the level of the termination of the cord form a

vertical bundle of nerves that resembles a horse’s tail and is

called the cauda equina

• Spinal Nerve Roots:

• Anterior root: consists of bundles of nerve fibers carrying

nerve impulses away from the central nervous system;

also called efferent fibers; go to skeletal muscle and

cause them to contract are called motor fibers.

• Posterior root: consists of bundles of nerve fibers that

carry impulses to the central nervous system; also called

afferent fiber; concerned with conveying information

about sensations of touch, pain, temperature, and

vibrations; also called sensory fibers.

• The cell bodies of these nerve fibers are situated in a swelling

on the posterior root called the posterior root ganglion

Plexuses:

• Cervical plexus

• Brachial plexus

• Lumbar plexus

• Sacral plexus

•Mucous Membranes:

• Line body cavities that open to the exterior (e.g.,

respiratory, digestive, and urogenital tracts)

• Secrete mucus to protect and lubricate surfaces

• Serous Membranes:

• Line body cavities not open to the exterior (e.g., thoracic

and abdominal cavities)

• Secrete serous fluid to reduce friction between organs

Bone

•is a living tissue capable of changing its structure as

the result of the stresses to which it is subjected. Like

other connective tissues, bone consists of cells,

fibers, and matrix.

• Forms:

• Compact: appears as a solid mass

• Cancellous: consists of a branching network of trabeculae

Bone Marrow

• Bone marrow occupies the marrow cavity in long and short

bones and the interstices of the cancellous bone in flat and

irregular bones.

• All bone surfaces, other than the articulating surfaces, are

covered by a thick layer of fibrous tissue called the

periosteum. The periosteum has an abundant vascular

supply, and the cells on its deeper surface are osteogenic.

Cartilage

• a form of connective tissue in which the cells and fibers are

embedded in a gel-like matrix, the latter being responsible for

its firmness and resilience. Except on the exposed surfaces in

joints, a fibrous membrane called the perichondrium covers

the cartilage.

Hyaline cartilage: has a great resistance to wear and

covers the articular surfaces of nearly all synovial joints

• Fibrocartilage: has many collagen fibers embedded in a

small amount of matrix and is found in the discs within

joints (e.g., the temporomandibular joint, sternoclavicular

joint, and knee joint) and on the articular surfaces of the

clavicle and mandible.

• Elastic cartilage: flexible and is found in the auricle of the

ear, the external auditory meatus, the auditory tube, and

the epiglottis.

• Sex Differences:

• Adult male tends to be taller than the adult female and to have longer

legs; his bones are bigger and heavier, and his muscles are larger

• Adult female has more subcutaneous fat and fat accumulations in the

breasts, buttocks, and thighs, giving her a more rounded appearance

• Racial Differences:

• seen in the color of the skin, hair, and eyes and in the shape and size of

the eyes, nose, and lips

• Age-Related Changes:

• After birth and during childhood, the bodily functions become

progressively more efficient, reaching their maximum degree of

efficiency during young adulthood. During late adulthood and old age,

many bodily functions become less efficient