Systematic Anatomy Lecture 1

Question 1

Superior

Answer 1

Towards the head end or upper part of the body.

The head is superior to the foot.

Question 2

Inferior

Answer 2

Away from the headend of towards the lower part of the body.
The intestines are inferior to the liver.

Question 3

Medial

Answer 3

Towards or at the midline of the body.

The heart is medial to the lungs.

Question 4

Lateral

Answer 4

Away from the midline of the body.

The thumb is lateral to the pink.

Question 5

Proximal

Answer 5

Closer to the origin of the body part or the attachment point of a limb to the body trunk.
The elbow is proximal to the wrist.

Question 6

Distal

Answer 6

Away from the origin of the body part or the attachment point of a limb to the body trunk.
The knee is distal to the thigh.

Question 7

Ipsilateral

Answer 7

On the same side.

The right foot and right hand are ipsilateral.

Question 8

Contralateral

Answer 8

The right foot and left hand are contralateral.

Question 9

Anterior/Ventral

Answer 9

Towards or at the front of the body.

The sternum is anterior to the heart.

Question 10

Posterior/Dorsal

Answer 10

Toward or at the back of the body.

The vertebra is posterior to the heart.

Question 11

Superficial

Answer 11

Closer to the surface of the body.

The skin is superficial to the skeletal muscle.

Question 12

Deep

Answer 12

The lungs are deep to the skin.

Question 13

What are the basic features that vertebrates share?

Answer 13

Humans are in the group of animals called vertebrates with cats, rats, birds, lizards, frogs and fish and share basic features.

1. Tube with a tube body plan.
2. Bilateral symmetry - the right half of the body is a mirror image of the left half.
3. Dorsal hollow nerve cord - All vertebrate embryos have a hollow nerve cord that runs along the back of the median plane. This cord develops into the brain and spinal cord.
4. Notochord and vertebrae - The notochord is a stiffening rod just deep to the spinal cord. In humans, a couple notochord forms in the embryo although it is quickly replaced with the vertebrae, the bony pieces in the vertebral column, or the backbone. Still some of the notochord persists throughout life as the cores of the discs between the vertebrae.
5. Segmentation - The outer tube of the body shows evidence of segmentation. Segments are the repeating units of similar structures from the head along the full length of the trunk. In humans the ribs and the muscle between the ribs is evidence of segmentation. Also the bony vertebral column with its repeating vertebrae is also segmented.
6. Pharyngeal pouches - Humans have a pharynx which is the throat region of the digestive and respiratory tube. In the embryonic stage, human pharynx have a set of outpocketing’s called pharyngeal pouches that correspond to the clefts between the fills of fish. These pouches can give a rise to structures in the head or neck. An example is the middle ear cavity which runs from the eardrum to the pharynx.

Question 14

What are the two largest cavities?

Answer 14

The dorsal cavity and the ventral cavity. They are closed to the outside and each contain organs to protect them. (Like toy boxes holding toys)

Question 15

What is the dorsal cavity?

Answer 15

The dorsal cavity is subdivided into the cranial cavity, which lies in the skull and encases the brain, and vertebral cavity, which runs along the vertebral column to encase the spinal cord. The hard bony walls of this cavity is what protects the organs.

Question 16

What is the ventral cavity?

Answer 16

The larger cavity of the two. The organs it contains such as the lungs, heart, intestines and kidneys are called visceral organs or viscera.

Split into two main divisions: (1) A superior thoracic cavity surrounded by the ribs and muscle of the chest wall (2) the inferior abdominopelvic cavity surrounded by the abdominal wall and the pelvic girdle.
The thoracic and abdominal cavities are separated from each other by the diaphragm, a domed shaped muscle used in breathing

The thoracic cavity is divided into parts: (a) two lateral parts containing a lung each surrounded by a pleural cavity (b) a central band of organs called the mediastinum. The mediastinum contains the heart surrounded by a pericardial cavity. It also houses other major thoracic organs such as the oesophagus and trachea.

The abdominopelvic cavity is divided into two parts, the abdominal cavity, which contains the liver, kidney, stomach and other organs, and the pelvic cavity which contains the bladder, some reproductive organs and the rectum. These two cavities are not separated by muscles and are continuous with each other. Many organs in the abdominopelvic cavity are surrounded by a peritoneal cavity.

Question 17

Circulatory / cardiovascular system.

Answer 17

Circulates blood around the body via the heart, arteries and veins. Delivers oxygen and nutrients to organs and cells. Regulates body temperature.

Question 18

Digestive system.

Answer 18

Takes down the food to be absorbed into nutrients. Waste is removed by the gastrointestinal tract. Includes the mouth, oesophagus, stomach and intestines.

Question 19

Endocrine system.

Answer 19

Glands secrete hormones that regulate processes such as growth, reproduction and nutrient use by body cells. Includes the hypothalamus, pituitary, pineal, thyroid, thymus and adrenal glands.

Question 20

Respiratory system.

Answer 20

Keeps blood constantly supplied with oxygen and removes carbon dioxide. The gaseous exchanges occur through the walls of the air sacs of the lungs. Includes the nasal cavity, pharynx, larynx, trachea, brachium and lungs.

Question 21

Skeletal System.

Answer 21

Protects and supports body organs and provides a framework the muscles use
to cause movement. Blood cells are formed within bones. Bones store minerals. Includes bones and joints.

Question 22

Muscular system.

Answer 22

Allows manipulation of the environment, locomotion, and facial expression. Maintains posture and produces heat.

Question 23

Nervous system.

Answer 23

As the fast-acting control system of the body, it responds to internal and external changes by activating appropriate muscles and glands.

Question 24

Integumentary system.

Answer 24

Forms the external body covering and protects deeper tissues from injury. Synthesizes vitamin D and houses cutaneous receptors (pain, pressure, etc.) and sweat and oil glands.

Question 25

Urinary System.

Answer 25

Eliminates nitrogenous wastes from the body. Regulates water, electrolyte, and acid-base balance of the blood.

Question 26

Reproductive system.

Answer 26

Overall function is production of offspring. Testes produce sperm and male sex hormone, and male ducts and glands aid in delivery of sperm to the female reproductive tract. Ovaries produce eggs and female sex hormones. The remaining female structures serve as sites for fertilization and development of the fetus. Mammary glands of female breasts produce milk to nourish the newborn.

Question 27

What are X-rays?

Answer 27

X-rays are electromagnetic waves of very short wavelengths. The X-rays are directed to the body and some are absorbed. The absorption depends on the density of the structure. More dense structures such as bones absorb more X-rays and appear lighter on the image where as less dense structures like soft organs appear darker. Used to identify tumours through low dose x-rays. For better views of the soft tissue organs, a contrast medium (a liquid that contains atoms of a heavy element such as barium that absorb more x-rays) could be injected or ingested deepening on the structure. The gastrointestinal tract is examined using this procedure to identify ulcers or tumours. limitation = image of soft tissues are blurry. 3D structure is flattened to a 2D image. Organs appear stacked on one another. More dense organs block the less dense organs in the same path.

Question 28

What is computed tomography (CT)?

Answer 28

A CT scanner is shaped like a square metal nut standing on its side. The patient lies in the central hole situated between the X-ray tube and the recorder. The recorder and the rotate to take 12 successive images around the persons full circumference to give the best view of the organs without obstruction. The computer translates all the recorded information into detailed pictures of the body section. CT provides superb images of soft tissue, bones and blood vessels.

Question 29

What is angiography?

Answer 29

A contrast medium is injected into the blood vessels and distributed through the vascular system. This gives. clear view of the blood vessels. Can be used for the diagnosis of aneurisms (widening of blood vessels) or atherosclerosis (narrowing of blood vessels). An extended angiography is called a digital subtraction angiography which takes an image before and after, and the before image is subtracted from the after image to give an unobstructed view of the blood vessel. Used to identify blockages in the arteries.

Question 30

What is positron emission tomography?

Answer 30

Used to indicate regions of cellular activity through the detection of radioactive isotopes injected into the body through the bloodstream. The isotopes are traced to the body that take up the greatest quantity. Once the radioactive material decays, gamma rays are emitted which are translated to electrical impulses and sent to the computer which produces an image. Could assess tumours because tum ours have increased cellular growth. Limitation - low resolution.

Question 31

What is Magnetic Resonance Imaging (MRI)?

Answer 31

Produces high contrast images of soft tissues in which x-rays are weak. Also does not use radiation to form the image. MRI detects the levels of hydrogen in the body, most of which is water. Therefore, MRI tends to distinguish body tissues from one another on the basis of different water levels. Because bones have lower water content than other tissues, the MRI peers through the skull easily to distinguish the fatty white matter from the grey more watery matter of the brain. This allows tumours to be spotted distinctively. The patient is subjected to magnetic fields up to 60,000 stronger than those on earth. This is done by the patient lying in a chamber surrounded by the magnet. When the magnet is turned on, the nuclei of the hydrogen atoms line up parallel to the magnetic field. The patient is then exposed to a brief pulse of radio waves which knock the spinning protons out of alignment. When the radio waves are turned off, they return to their alignment releasing faint radio waves of their own, which are detected and translated in images. Multiple MRI scans can be assembled into 3D reconstructions.