External form of the heart
The arterial end of the primitive heart delivers blood to the paired dorsal aortae—longitudinal vessels on each side of the notochord. The vessels that connect the heart to the dorsal aortae bend around the foregut from ventral to dorsal. These aortic arch arteries pass through swellings in the neck region filled with mesenchyme known as […]
33. Pericardium and heart
Optional Reading Clinically Oriented Anatomy, 8th ed., Overview of mediastinum section through Clinical box: Heart. Would a review be helpful? We already covered the location of the pericardium and heart, the pericardium, and the external anatomy of the heart in the introduction to the thoracic cavity. Internal anatomy of heart Overview of chambers The adult […]
00. The pleura and lungs
Optional Reading Clinically Oriented Anatomy, 8th ed., Viscera of thoracic cavity section through Clinical box: Pleurae, lungs, and tracheobronchial tree; The Developing Human: Clinically Oriented Embryology, 11th ed., chapter 10. Pleural recesses In most areas, the pleural cavity is a “potential” space where the visceral pleura on the lungs touches the parietal pleura on the […]
5. The vertebral column
Optional Reading Clinically Oriented Anatomy, 8th ed., Vertebral Column section (only the sections on intervertebral discs, longitudinal ligaments), Movements of vertebral column, and Curvatures of vertebral column. The vertebral column (“backbone” or “spine”) consists of a series of bones, the vertebrae, firmly connected together by joints and ligaments. The vertebral column is the “axis” of […]
12. The thoracic wall
Optional Reading Clinically Oriented Anatomy, 8th ed., Overview of Thorax section through The bottom line: Muscles and neurovasculature of thoracic wall. The walls surrounding the thoracic cavity are made from layers of muscles and fascia that are reinforced by the thoracic skeleton (“rib cage”). The thoracic wall is cone-shaped; narrower above and wider below. The […]
8. Pectoral region and breast
Optional Reading Clinically Oriented Anatomy, 8th ed., Overview of thorax, Pectoral and scapular region, Breasts. Pectoral region The pectoral region is located in the anterior thorax on each side of the sternum, between the clavicle and axilla (armpit). It links the upper limb to the trunk and supports the breast. Figure 8.1 Muscles of pectoral […]
3. Introduction to the nervous system
Divisions of the nervous system Anatomic subdivisions: Central nervous system (CNS) Read More Brain and spinal cord. Peripheral nervous system (PNS) Read More Nerves and ganglia. Functional subdivisions of the nervous system are classified not on topography, but according to the organs and tissues they supply: Somatic nervous system Read More Supplies structures that we […]
Week 4 of human development: Folding of the embryonic disc and division of the intraembryonic coelom
The human body form arises through cranial, caudal, and lateral folding of the embryonic disc. Hold onto your seats, folks . . . At the end of the 3rd week, the trilaminar embryonic disc is flat and oval in shape. During the 4th week, the disc grows rapidly, especially in length, and undergoes a complicated […]
Week 3 of human development
Two important events occur during Week 3: The process of GASTRULATION, which forms the “germ” layers of the embryo Differentiation of the MESODERM (one of the germ layers) Note Development of the neural tube (future central nervous system) begins in Week 3, but carries over into Week 4. Gastrulation Gastrulation is the process of converting […]
Week 2 of human development: The “week of twos”
Trophoblast goes wild Early in the second week, some trophoblast cells lose their cell membranes and coalesce into a mass of cytoplasm with many scattered nuclei (= a syncytium). Called the syncytiotrophoblast, this invasive mass burrows into the spaces between endometrial cells, pulling the blastocyst into the endometrium. The trophoblast cells internal to the syncytiotrophoblast […]