Medical School

A graphical representation of the Electrical conduction system of the heart showing the Sinoatrial node, Atrioventricular node, Bundle of His, Purkinje fibers, and Bachmann’s bundle.

Areas of localization on the outer surface of hemisphere of the human brain

Motor area in red, Area of general sensations in blue, Auditory area in green, and Visual area in yellow. The dotted regions represent the psychic portions of the respective areas.

Anatomy lesson: organs of the abdominal cavity

Normal and Diseased Heart Valves

Diagram of the vestibular system

Cross section of an artery, vein and capillary

Anatomy Lesson: Taste Bud of the Human Tongue

These mimic Frank Netter in many ways, but updates Netter’s legendary paintings for the digital age. Gorgeous.

(via Marcin Oleksak’s Medical Illustrations at Street Anatomy)

(via jayparkinsonmd)

Structure of a neuron

(a) Structure of a multipolar neuron such as a spinal motor neuron. (b) Photograph of this neuron type. (c) Detail of the myelin sheath. (d) Neurofibrils of the soma. (e) Nissl bodies, stained masses of rough ER separated by the bundles of neurofibrils shown in part (d).

Variations in Neuron Structure

Top row, left to right: Two multipolar neurons of the brain—a pyramidal cell and a Purkinje cell. Second row, left to right: Two bipolar neurons—a bipolar cell of the retina and an olfactory neuron. Third row: A unipolar neuron of the type involved in the senses of touch and pain. Bottom row: An anaxonic neuron (amacrine cell) of the retina.

The cells of the epithelial tissue are tightly packed and rest on a thin basement membrane. The free surface of the epithelium is exposed to air or fluid. No blood vessels are present. Epithelial tissues are classified according to the shape of the component cells and the arrangement of these cells into one or more layers.  The shapes of the cells may be:

squamous — flat, scale-like cells (“fried-egg” appearance).

cuboidal — cells appear square in side view with nucleus in a central position.

columnar — cells appear rectangular in side view with the nucleus displaced toward the base of the cell.

Anatomy Lesson: Trapezius Muscle

In human anatomy, the trapezius is a large superficial muscle that extends longitudinally from the occipital bone to the lower thoracic vertebrae and laterally to the spine of the scapula (shoulder blade). Its functions are to move the scapulae and support the arm.

Anatomy Lesson: The Cranial Nerves

There are 12 paired cranial nerves that exit the skull under the brain’s surface that extend to various parts of the head, neck, chest and abdomen. The cranial nerves comprises three nerve types: motor nerves that send an impulse signal to a muscle; sensory nerves that transmit sensations from the body back to the brain; and autonomic nerves with both motor and sensory components that monitor and control visceral functions such as salivation, heart rate and intestinal movement.

The 12 cranial nerves are:

I olfactory
II optic
III oculomotor
IV trochlear
V trigeminal
VI abducens
VII facial
VIII vestibulocochlear
IX glossopharyngeal
X vagus
XI accessory
XII hypoglossal

Anatomy Lesson: Organs of the Abdominal Cavity

Illustration of the human brain