MS-1 FUND 1: 10:10-11:00
Wednesday, September 10, 2014
Dr. Zehren
Introduction to Anatomy & Medical Terminology
Transcriber: Katherine Shelton
Editor: Lissa Handley Tyson
Page 1 of 5
Abbreviations: CT – connective tissue, ANS – autonomic nervous system, SCM – sternocleidomastoid, CNS – central nervous system
Introductory Comments: This transcript is for Dr. Zehren’s Introduction to Anatomy & Medical Terminology lecture.
Before lecture, Dr. Cotlin stated that these anatomy lectures will be similar to histology lectures in that written exams will
have content taken from them, but identification based on pictures will only be in the anatomy lab practical at the end of
the course. There is a handout to accompany this lecture available on MedMap.
I.
II.
III.
IV.
V.
Fundamentals of Word Structure (slide 4) timestamp
a. Medical terms have three component parts: (slide 5) 2:55
i. Word root – conveys the central meaning of a word
ii. Prefix – “to fix before”; a syllable/group of syllables before the root that alters meaning or creates new word
iii. Suffix – “to fasten on”; a syllable/group of syllables after the root that alters meaning or creates new word
1. When breaking a word down into components, begin with the suffix meaning and work backwards
b. Examples of three part structure
i. Mal/format/ion – the process of being badly shaped (slide 6) 3:26
1. Mal – prefix meaning “bad”
2. Format – root meaning “a shaping”
3. Ion – suffix meaning “process
4. Best to start with the suffix – “process of being badly shaped” makes more sense than “bad shaping
process”
ii. Chemo/therapy – treatment of disease using chemical agents (slide 7) 4:12
1. Chemo – combining form meaning “chemical”
a. Combining form – word root to which a vowel has been added as a link to suffix; vowel is
usually “o”
2. Therapy – suffix meaning “treatment”
c. Spelling and pronunciation are also important (slide 8) 5:28
i. Spelling example – abduct means “to lead away, adduct means “to lead toward”
ii. Pronunciation example – the “p” in ptosis (drooping or falling) is silent; pronunciation is “to’sis”
Structure names have meaning
a. Shape – e.g. the trapezius muscle is shaped like a trapezoid (slide 9) 6:38
b. Form– e.g. the digastric muscle in the jaw has “two bellies”, the fleshy part of the muscle (slide 10) 7:04
c. Function – the levator scapulae muscles elevate the scapula (slide 11) 7:18
d. This is why it is important to use a structure’s proper name instead of an eponym (the name derived from the
person who discovered it)
Anatomical Position (slide 13) 7:56
a. All anatomical descriptions are in relation to this specific position to prevent ambiguity
b. Body erect; head, eyes, and toes directed forward; upper limbs held by side so that palms of hands face
forward; and lower limbs close together
Anatomical Planes (slide 15) 8:41
a. Three major anatomical planes
i. Median – vertical plane that passes longitudinally through body and divides it into right and left halves
1. Sagittal – any plane parallel to the median plane
ii. Coronal (aka frontal) – any vertical plane that intersects median plane at right angle and divides body into
front and back parts
iii. Horizontal (aka transverse, axial) – any plane at right angle to both the median and coronal planes;
divides body into upper and lower parts
b. Oblique planes also exist and are not perpendicular to any of the major three
Terms of Relationship and Comparison (slide 17) 9:38
a. Medial (towards midline) vs. lateral (away from midline)
i. E.g. the fifth digit is medial to the thumb; the thumb is lateral to the fingers
b. Anterior/ventral (towards front) vs. posterior/dorsal (towards back)
i. E.g. the toes are anterior to the heel; the heel is posterior to the toes
c. Superior/cranial (towards the head) vs. inferior/caudal (towards the feet)
i. E.g. the heart is superior to the stomach
ii. For the foot, it is customary to use dorsum and plantar surface (sole) instead of superior and inferior
iii. For the hand, dorsum and palmar surface (palm) are used
d. Proximal vs. distal (in relation to limbs)
i. Proximal is towards the attached portion; distal is away from the attached portion
ii. E.g. the elbow is proximal to the wrist and distal to the shoulder
e. Superficial (towards surface) vs deep (towards interior)
MS-1 FUND 1: 10:10-11:00
Wednesday, September 10, 2014
Dr. Zehren
Introduction to Anatomy & Medical Terminology
Transcriber: Katherine Shelton
Editor: Lissa Handley Tyson
Page 2 of 5
Abbreviations: CT – connective tissue, ANS – autonomic nervous system, SCM – sternocleidomastoid, CNS – central nervous system
i. E.g. the skin is superficial to the humerus
ii. Intermediate position – between superficial and deep (e.g. the muscle is in an intermediate position
between skin and humerus)
f. Combined terms can also be used – (e.g. the breast lies suprolateral to the umbilicus)
VI. Terms of Movement (slide 18) 12:14
a. There are three axes around which joints can move(S.N. movement around the horizontal axis is shown on slide 19; movement
around the anterior-posterior and vertical axes is shown on slide 20)
i. Horizontal axis –passes from lateral to medial through the body (S.N. this is best illustrated on slide 19).
1. Flexion and extension occur around the horizontal axis
a. Flexion – bending or decreasing the angle between parts of the body (e.g. moving the arm or
leg forward at the shoulder or hip joint, bending fingers)
b. Extension – straightening or increasing the angle between parts of the body (e.g. moving the
arm or leg backwards at the shoulder or hip joint, straightening fingers)
ii. Anterior-posterior axis – passes through the body from anterior to posterior
1. Abduction and adduction occur around this axis
a. Abduction – moving away from the midline
b. Adduction – moving towards the midline
iii. Vertical axis – passes through the body from inferior to superior
1. Medial (internal) and lateral (external) rotation occur around the vertical axis
a. Medial – twisting inwards
b. Lateral – twisting outwards
b. A multi-axial joint allows movement around all three axes. Joints can also be uniaxial, with movement around
one axis, or biaxial, with movement around two axes
i. Circumduction refers to movement that combines all three axes and involves flexion, extension,
abduction, and addiction (e.g. moving the arm in a cone-shaped pattern from the shoulder joint)
c. Supination and pronation are movements of the forearm and hand and correspond to lateral and medial
rotation, respectively
d. ARS question at 15:45
VII. Skeletal System (slide 21) 16:50
a. Osteology – the study of the skeletal system
b. Consists of bones and cartilages, and joints (articulations) between them
c. Functions and Classification of Bones (slide 22) 17:07
i. Functions
1. Support body
2. Protect organs
3. Attachment of muscles – bones act as levers for movement
4. Marrow and hemopoietic function (e.g. sternum)
5. Storage and exchange of Ca2+ and PO43- ions
ii. Bones can be classified in several ways
1. Developmentally
a. Cartilage bones – preformed by cartilage (e.g. humerus)
b. Membrane bones – ossify directly from mesenchyme (e.g. clavicle)
2. Regionally
a. Axial skeleton – bones of skull, vertebrae, ribs, and sternum
b. Appendicular skeleton – bones of limbs and limb girdles (e.g. shoulder and hip)
3. Shape
a. Long (e.g. humerus)
b. Short (e.g. wrist bones)
i. Sesamoid bones – embedded within a tendon (e.g. patella)
c. Flat (e.g. sternum)
d. Irregular (e.g. vertebrae)
d. Joints – any connection between parts of skeletal system; place where bones articulate with each other (slide
23) 19:05
i. Synovial joints – most important joints in gross anatomy; united by articular capsule; permit free
movement. Synovial joints share some common characteristics: (slide 24) 19:12
1. Articular capsule composed of outer fibrous layer and inner synovial membrane
a. Fibrous layer made of CT and blends with periosteum covering bone may be thickened to
form intrinsic ligaments
i. Ligaments – CT bands that unite bone to bone
MS-1 FUND 1: 10:10-11:00
Wednesday, September 10, 2014
Dr. Zehren
Introduction to Anatomy & Medical Terminology
Transcriber: Katherine Shelton
Editor: Lissa Handley Tyson
Page 3 of 5
Abbreviations: CT – connective tissue, ANS – autonomic nervous system, SCM – sternocleidomastoid, CNS – central nervous system
1. Intrinsic – confined to capsule
2. Extrinsic – outside articular capsule
b. Synovial membrane – vascular layer, secretes synovial fluid the consistency of egg white
or “runny honey” into synovial cavity
i. Synovial fluid lubricates joints and nourishes articular cartilage
ii. Synovial membrane does not cover articular cartilage
2. Joint (synovial) cavity filled with synovial fluid is present between the two bones
3. Articulating surfaces of the bones are covered with articular cartilage (may be hyaline or
fibrocartilage)
a. Meniscus – intra-articular disc present in some, but not all, synovial joints (e.g. the knee)
i. Menisci help spread synovial fluid, add stability, and permit different types of movement
to occur on either side of the meniscus
VIII. Muscular system (slide 25) 22:47
a. Myology – study of muscles
b. Muscle fibers produce contraction and movement
c. Muscular system consists of muscles that act to move or position body parts
d. Classification of muscle tissue (slide 26) 23:05
i. Skeletal – attaches to bones at either end, usually crosses at least one joint (exception – facial muscles
attach to facial bones and to skin); voluntary
1. Majority of muscles dissected in anatomy lab are skeletal
ii. Cardiac – found in wall of heart; involuntary and innervated by ANS
iii. Smooth – found in walls of organs such as stomach, ducts, and walls of blood vessels (except for
capillaries); involuntary and innervated by ANS
e. Origin vs. Insertion (using SCM as example) (slide 27) 25:04
i. Sternocleidomastoid (SCM) – named because one end is attached to the sternum/clavicle and the other
is attached to the mastoid process
ii. Origin is fixed end; insertion is movable end
1. Usually, sternum and clavicle are fixed so when SCM contracts (bilaterally) the head and neck are
flexed
2. If the head and neck are held stationary by muscles in the back of the neck, contraction of SCM can
elevate the sternum
a. Shows that muscles can work in reverse – sometimes the origin may become the movable
part
f. Fleshy vs. fibrous component (slide 28) 27:00
i. Fleshy (belly) component – actual muscle tissue
1. Contractile
2. High metabolic activity, very vascular – with ischemia muscle pain and fatigue occur
3. Low tensile strength – 77 lb./in2 will tear skeletal muscle
4. Cannot withstand pressure
5. Force is dissipated so leaves no mark on bone
ii. Fibrous component (tendon or aponeurosis)
1. Not contractile tissue, attaches fleshy part to bone
a. Cylindrical component is a tendon, flat is an aponeurosis
2. Low metabolic activity, sparse blood supply, not many cells
3. High tensile strength – can withstand sudden strain (8,600 – 18,000 lb./in2) without rupturing
4. Can withstand pressure
5. Leaves tubercules, ridges, etc. on bones because force is concentrated at the point of attachment
(e.g. on the radius, there is a radial tuberosity where the tendon of the biceps attaches)
g. Motor unit – a motor neuron (nerve cell) in the CNS, its axon, and all skeletal muscle fibers innervated by the
axon (slide 29) 29:56
i. Size of motor unit varies: the more precise the action of a muscle, the smaller its motor units
1. E.g. extraocular muscles control fine movement of the eyeball and have ~3 fibers/motor unit
2. E.g. hip and thigh muscles control coarse leg movement and have 150-1,600 fibers/motor unit
ii. All muscle fibers in the motor unit contract simultaneously (i.e. all or none), so motor unit is smallest muscle
unit that can undergo isolated contraction
iii. Contraction of motor units is automatically rotated to minimize fatigue – not all motor units are engaged at
once
1. One can voluntarily control strength of contraction by engaging more motor units
MS-1 FUND 1: 10:10-11:00
Wednesday, September 10, 2014
Dr. Zehren
Introduction to Anatomy & Medical Terminology
Transcriber: Katherine Shelton
Editor: Lissa Handley Tyson
Page 4 of 5
Abbreviations: CT – connective tissue, ANS – autonomic nervous system, SCM – sternocleidomastoid, CNS – central nervous system
2. Can also voluntarily contract only a specific part of the muscle –important when a muscle has
multiple functions
iv. Neuromuscular junction – connection of nerve fibers to skeletal muscle
1. Nerve fibers release acetylcholine at this junction; communication is called cholinergic
a. Curare blocks action of acetylcholine and produces complete relaxation of muscles
h. Sensory Innervation to Skeletal Muscles (slide 30) 32:45
i. 40-50% of nerve fibers to skeletal muscles are sensory fibers, not motor fibers
1. Some sensory fibers transmit pain information
2. Some sensory fibers transmit information from organs called muscle spindles and tendon spindles
(proprioceptors)
a. Proprioceptors are sensitive to muscle stretch or tension; send nervous system information
important for maintaining balance, posture, and locomotion
b. Proprioceptors (and their sensory fibers) help regulate reflexes that maintain necessary
degree of muscle contraction
ii. (S.N. The figure on slide 30 shows A) a simple reflex arc that allows communication between the nervous system and muscle/tendon
spindles, B) an axon from a motor neuron synapsing on a muscle fiber, and C) the structure of a muscle spindle)
IX. Skin and Fascia (slide 31) 34:08
a. Skin provides many important functions (slide 32) 34:25
i. Protection of body from environment (abrasions, UV radiation, microorganisms)
ii. Containment of body’s vital substances and prevention of dehydration
iii. Heat regulation through sweat and dilation/constriction of superficial blood vessels
iv. Sensation (pain, temperature, and touch) monitored via superficial (cutaneous) nerves
v. Synthesis and storage of Vitamin D
b. Skin and some of its specialized structures (slide 33) 34:06
i. Epidermis – superficial layer of skin; cellular with a tough, keratinized outer layer for protection and a deep
basal layer for regeneration
ii. Dermis – deep layer of skin containing CT (collagen and elastic fibers), hair follicles with arrector muscles
and sebaceous glands
1. Collagen provides strength and toughness; elastic fibers provide tone and deteriorate with age
2. Arrector pilar muscles – cause hair to stand up when cold or frightened
3. Sebaceous glands – secrete oily substance
iii. Superficial fascia – composed of loose CT and fat; also contains sweat glands, superficial blood and
lymphatic vessels, and cutaneous nerves
1. Level of fat varies – there is less in the back of hands and more in the breasts, thighs, and stomach
2. Superficial blood and lymph vessels branch into the dermis to form vascular beds that nourish the
avascular epidermis
3. Cutaneous nerves send fibers into the dermis and epidermis
a. Some have afferent (sensory) nerve endings and others innervate sweat glands and
arrector muscles with motor (sympathetic) fibers
iv. Deep fascia – lies beneath superficial fascia and covers skeletal muscle tissue
c. Functions of deep fascia
i. Binds down muscles and gives form to body (e.g. fascia latae in the thigh forms a sleeve around thigh
muscles, binding and giving the thigh shape (slide 34) 42:05
ii. Forms sheaths for blood vessels and nerves (e.g. femoral sheath surrounds femoral arteries and veins)
iii. Provides for attachment of muscle fibers (e.g. gluteus maximus and tensor fasciae latae muscles insert into
the iliotibial tract, a thickening of the deep fascia on lateral side of thigh) (slide 35) 42:37
iv. Binds down tendons (e.g. extensor retinacula prevents tendons anterior to ankle joint from bow stringing
away from bones; fibular retinacula performs same function for tendons of the fibrularis muscle) (slide 36)
43:07
v. Provides protection for vessels and nerves (e.g. palmar aponeurosis is a thickening of deep fascia which
protects underlying superficial palmar arterial arch and cutaneous nerves) (slide 37) 43:20
vi. Compartmentalizes body – the leg can be divided into three osteofascial compartments (anterior,
posterior, and lateral) by the deep (crural) fascia of the leg; each compartment has own nerve and blood
supply (slide 38) 43:50
1. These compartments are separated by the anterior, posterior, and transverse intermuscular
septa
2. Anterior compartment contains dorsiflexors of the foot and toes; supplied by deep fibular nerves
and anterior tibial vessels (slide 39)
MS-1 FUND 1: 10:10-11:00
Wednesday, September 10, 2014
Dr. Zehren
Introduction to Anatomy & Medical Terminology
Transcriber: Katherine Shelton
Editor: Lissa Handley Tyson
Page 5 of 5
Abbreviations: CT – connective tissue, ANS – autonomic nervous system, SCM – sternocleidomastoid, CNS – central nervous system
3. Posterior compartment contains plantar flexors of the foot; supplied by superficial fibular nerves and
fibular vessels
4. Lateral compartment contains evertors of the foot; supplied by tibial nerves and posterior tibial
vessels
d. Compartment syndrome and fasciotomy (slide 40) 46:00
1. Tight fascia and intermuscular septa resist expansion of leg compartments
a. Trauma may result in edema (swelling) which increases pressure
b. Circulation is affected (causing ischemia)
c. Necrosis occurs in the 4-6 hours following ischemia
2. Fasciotomy – cutting deep fascia/intermuscular septa
3. Shin splints – mild form of anterior compartment syndrome from overexertion of anterior
compartment muscles
e. Deep fascia prevents and directs spread of infection (slide 41) 47:25
i. Deep fascia of the neck
1. Buccopharyngeal fascia covers posterior walls of pharynx and esophagus
2. Prevertebral fascia covers muscles in front of vertebral column
3. Retropharyngeal space between these extends from base of skull to posterior mediastinum in
chest; is filled with loose areolar CT to allow pharynx and esophagus to expand during swallowing
4. If an infection develops in the wall of the pharynx/esophagus, the buccopharyngeal fascia will
prevent the spread into the retropharyngeal space and chest (unless the buccopharyngeal fascia is
pierced)
X. Body Cavities (slide 42) 49:10
a. Real spaces are body cavities that contain organs (viscera)
i. Thoracic cavity is bounded by the thoracic inlet superiorly, thoracic diaphragm inferiorly, sternum
anteriorly, and thoracic vertebrae posteriorly. It contains the heart, lungs, trachea, and esophagus
ii. Abdominal cavity is bounded by thoracic diaphragm superiorly, pelvic inlet inferiorly, and muscles and
bones of abdominal wall anteriorly and posteriorly. It contains many organs of digestion (e.g. stomach,
intestines, liver, pancreas)
iii. Pelvic cavity is bounded by pelvic inlet superiorly, pelvic muscular diaphragm inferiorly, and muscles and
bones of pelvic wall anteriorly and posteriorly. It contains parts of the urinary system (bladder) and
reproductive system (e.g. uterus, fallopian tubes, prostate gland, seminal vesicles)
1. The pelvic inlet is an imaginary plane passing from pubic symphysis to sacral promontory, so the
pelvic and abdominal cavities are continuous and referred to sometimes as the abdominopelvic
cavity
iv. Cranial cavity is bounded by the skull and contains brain, proximal parts of cranial nerves, and blood
vessels
v. Spinal cavity (vertebral canal) is bounded by spinal column and contains spinal cord and proximal parts
of spinal nerves
b. Potential spaces normally do not contain anything but a thin film of fluid that keeps organs moist and prevents
friction, but can become filled with liquid or gas (slide 46) 50:10
i. Pleural (surrounding lungs) and pericardial (surrounding heart) cavities
ii. Parietal layer is the outer layer of a potential space and the visceral layer is the inner layer (in contact
with the organs) (slide 47) 51:00
1. The parietal and visceral layers are a continuous membrane and are in contact with one another
a. The enclosed cavity is completely closed
2. These layers also exist in the thoracic and pelvic cavities
3. Balloon example on slide 47 illustrates these layers
XI. Anatomical variation (slide 49) 53:30
a. All anatomical structures are variable – arteries in particular are highly variable
i. Variations can be clinically significant – if an artery is misplaced it can be mistaken for a superficial vein
and injected (causing arterial spasms and ischemia) or accidentally cut during surgery
ii. Veins may be different on different sides of the body
Student Questions: No student questions
<END OF LECTURE 55:39>