UPDATED Study Guide Exam 1 PDF

Exam 1 Study Guide Lecture 1 Some key de ni ons Anatomy: The study of form Cadaver dissec on: Cu ng and separa ng body ssues to reveal ssue rela onships Compara ve anatomy: Study of mul ple species to learn about form, func on, and evolu on Some key historical gures Aristotle of Stagira: Believed th...

Exam 1 Study Guide Lecture 1 Some key de ni ons Anatomy: The study of form Cadaver dissec on: Cu ng and separa ng body ssues to reveal ssue rela onships Compara ve anatomy: Study of mul ple species to learn about form, func on, and evolu on Some key historical gures Aristotle of Stagira: Believed that complex structures were made from simple parts. Deduced that there were wither natural or supernatural causes of illness. First a empted explana ons for the func ons of complex anatomical systems. Claudius Galen: Greco-Roman anatomist. Performed dissec ons on animals to deduce structure and func on in humans. Treated injured gladiators and was personal physician to emperor Marcus Aurelieus. Andreas Vesalius: Studied in the 16th century and performed his own dissec ons. Created the rst formal atlas of anatomy and disagreed with the previous approach of consul ng the works of Galen. Charles Darwin: First to propose Natural Selec on, the theory explaining how evolu on occurs. Natural selec on may be de ned as “The survival and reproduc on of some individuals over others because of hereditary di erences.” Key features of science A hypothesis can be de ned as an educated specula on possible answer to a ques on about the natural world. If we claim something is scien prove it wrong cally true, we must be able to specify what evidence it would take to ~~~All hypothesese must be falsi able ti fi ti ti ti ti ti ti ti ti ti ti tt ti ti ti ti ti ti fi fi ti fi ff tti fi fi ti ti fi fi ti ti ti A fact is a veri able truth Theories are comprised of hypotheses that explain larger phenomena. These hypotheses have been tested repeatedly before they are accepted into a hypothesis. Anatomical varia on is normal varia on within a species. It can be seen in di erences in arterial branching, muscle inser ons, nerve branching, or venous ow. Lecture 2 Among the extrinsic back muscles, the most super cial is the trapezius superiorly (inser ng into scapular spine) and la ssimus dorsi inferiorly, followed at the level of the scapula by the rhomboid major and minor. Extrinsic back muscles (i.e., trapezius, la ssimus dorsi, rhomboid major and minor, levator scapulae) are innervated by ventral rami of spinal nerves traveling through the brachial plexus. Intrinsic back muscles are innervated by dorsal rami. ti ff fl fi ti Innerva on ti Ac ons ti ti ti ti ti Muscl e La ssi mus dorsi Extends, adducts, and medially rotates humerus Elevates and Levato rotates the r scapula to lt the scapul glenoid cavity ae inferiorly Rhom boid major ti ti tt ti ti ti ti Muscle tt ti Rotates scapula to lt the glenoid cavity superiorly, Trapez elevates (superior ius part), retracts (middle part), and depresses (inferior part) scapula Motor: spinal accessory n. (CN XI) Proprioce p on: C3– C4 Thoracodorsal n. (middle subscapular n.) Dorsal scapular n. Retracts and rotates the scapula to lt the glenoid cavity inferiorly Medial A achments Lateral A achments Ac ons Innerva on La ssim us dorsi Levator scapula e Lateral one-third of the clavicle and acromion and spine of scapula Rotates scapula to lt the glenoid cavity superiorly, elevates (superior part), retracts (middle part), and depresses (inferior part) scapula Spinous processes T7– Floor of intertubercular sulcus of L5, thoracolumbar humerus fascia, sacrum, iliac crest, ribs Extends, adducts, and medially rotates humerus Transverse processes C1– C4 Elevates and rotates the scapula to lt the glenoid cavity inferiorly Spinal Rhombo processes T2– id major T5 Superior angle of scapula Motor: spinal accessory n. (CN XI) Proprioce p on: C3– C4 Thoracodorsal n. (middle subscapular n.) Dorsal scapular n. Medial border of scapula below spine Retracts and rotates the scapula to lt the glenoid cavity inferiorly Important neurovascular bundles include: a) transverse cervical artery (from thyrocervical trunk, subclavian artery) and spinal accessory nerve (Cranial nerve XI, more on this nerve later in the course), supplying trapezius b) dorsal scapular artery (branching o subclavian artery directly) and dorsal scapular nerve (direct branch o C5 ventral ramus) supplying rhomboid major and minor c) thoracodorsal artery (a subscapular artery branch, from axillary artery) and thoracodorsal nerve (from posterior cord of brachial plexus) supplying la ssimus dorsi All major arteries travel with veins of the same name in their respec ve bundles ti ti ff ti ti ff ti The spine ti ti Superior nuchal line, external Trapeziu occipital s protuberance, ligamentum nuchae, SP C7–T12 Cervical spinal nerves all exit superior to their respec ve vertebrae, except for the C8 spinal nerve which exits along the inferior intervertebral notch of the C7 vertebra. The C8 spinal nerve is thus found in the intervertebral foramen between the C7 and T1 vertebrae. The spine ends between the L1 and L2 vertebrae. Thus, procedures such as a spinal tap that enter the vertebral canal are performed at the L4/L5 juncture ad the safest op on. The spine has three meningeal layers: Dura mater, arachnoid mater, pia mater. Pia mater adheres closely to the spine itself. Arachnoid mater lies over the pia and, in the subarachnoid space, cerebrospinal uid ows. The dura mater overlies the arachnoid mater and it creates a sack (the dural or thecal sack) surrounding the spine. Outside of this sack is the epidural space lled with fat, a venous plexus, and the dorsal root ganglia laterally. The cauda equina or horse’s tail is created by the descent of spinal nerve rootlets down from the conus medularis (the distal-most part of the spine) to their respec ve intervertebral foramina further inferiorly. One solitary lum terminale (an extension of pia mater) hangs down the midline of the spinal cord to anchor it inferiorly. Lecture 3 Sub-occipital region Suboccipital nerve supplies motor innerva on to all suboccipital muscles. Is the only posterior ramus of a cervical spinal nerve with no cutaneous distribu on. Muscles of the suboccipital triangle receive motor innerva on from the suboccipital nerve. These include a) rectus capi s posterior major b) obliquus capi s inferior c) obliquus capi s superior Greater occipital nerve (dorsal ramus of C2) provides sensa on to the posterior scalp. Scapular region Rotator cu muscles include: Supraspinatus muscle (abductor of humerus, suprascapular nerve innerva on) Infraspinatus muscle (lateral rota on of humerus, suprascapular nerve innerva on) Teres minor (lateral rota on of humerus, axillary nerve innerva on) Subscapularis (medial rota on of humerus, upper and lower subscapular nerve innerva on) ti fl ti fl ti ti ti ti ti ti ti ti ti fi ti ti ff ti ti ti ti fi ff ti NOTE: Teres major is not a rotator cu muscle (medial rotator of humerus, lower subscapular nerve innerva on) Spaces of the posterior scapular region Quadrangular space: made from teres major and minor, and long and lateral heads of triceps muscle. This space admits posterior circum ex humeral artery and axillary nerve running together in a bundle. They supply teres minor and deltoid muscle. They are also suscep ble to damage during a fracture of the humeral surgical neck (not anatomical neck). Triangular interval Space between lateral and long heads of the triceps inferior to the teres major. Deep in the interval is the radial groove containing radial nerve and deep artery of arm (a brachial artery branch) The axilla Fat- lled space containing axillary fat, axillary vein, axillary artery (with cords of brachial plexus wrapped around it). Axillary artery is divided into three parts by the path of the pectoralis minor muscle. 1st part is medial to the muscle, 2nd part is under it, and 3rd part is lateral to it. These are: 1st part: containing one branch- the superior thoracic nerve 2nd part: containing two branches- the thoracoacromial artery (and its 4 branches, of which pectoral is the only one you will probably see clearly), and lateral thoracic artery 3rd part: containing subscapular artery (and its circum ex scapular & thoracodorsal branches), anterior humeral cicum ex artery and posterior circum ex humeral artery Axillary artery changes its name to brachial artery lateral to the teres major muscle lateral boundary Lecture 4 Parts of a vertebra include: Vertebral body Pedicle Transverse process Lamina ti fl fl fl fl fi Spinous process Superior and Inferior ar cular processes Five types of vertebrae. These include: Cervical: small body, foramina in transverse process for the vertebral artery Thoracic: Thicker bodies than cervical vertebrae. Have costal facets for rib ar cula ons. Ar cular facets are oriented coronally (side-to-side) Lumbar: Larger/thicker body, Lacks transverse foramina and costal facets. Sacrum: Five fused elements with sacral canal (the name for the sacral por on of vertebral canal) and ve pairs of sacral foramina through which sacral nerves exit The vertebral column has primary and secondary curves. Primary curves are present at birth and include the thoracic and sacral anterior curvatures. Secondary curves develop in late infancy/early childhood as upright walking is achieved, it includes lordo c curves of the cervical and lumbar regions. Three sets of ligaments cover over the vertebrae. These are: Anterior longitudinal ligament – running on anterior surfaces of vertebral bodies, responsible for resis ng excessive hyperextension of trunk Posterior longitudinal ligament- running on posterior surface of vertebral bodies, responsible for resis ng excessive exion of trunk Ligamenta ava- running between each adjacent pair of vertebral laminae. Assists in maintenance of posture and resump on of erect posture a er exion of trunk ti ti ti ti fl ti ft fi ti ti fl ti fl ti ti Note: hernia on of intervertebral disc leads to bulging into the intervertebral foramen as direct intrusion posteriorly into the vertebral canal is usually halted by posterior longitudinal ligament. Pain results when this hernia on involves the mixed spinal nerve or radicle that is located in the intervertebral foramen as it contains sensory and motor bers. ti fi Vertebral notch Spinal cord The spinal cord has dorsal and ventral horns in the gray ma er. The brain and spine are parts of the central nervous system whereas the nerve roots are parts of the peripheral nervous system. Ventral horn contains cell bodies of motor/e erent soma c nerves. Dorsal root ganglia contain cell bodies of all sensory nerves (soma c and visceral). They do not synapse here. Dorsal roots that emerge from dorsal horn carry sensory bers (both soma c and visceral). Ventral roots carry ti ti tt ti fi soma c e erent bers ff fi ff ti preganglionic sympathe c bers at T1-L2 levels. preganglionic parasympathe c bers at the S2-S4 levels (associated with pelvic splanchnics, more on this later in the study guide). Dorsal and ventral roots combine to form a mixed spinal nerve or radicle, containing all contents of the dorsal and ventral roots (sensory and motor). These split into dorsal ramus and ventral ramus. Dorsal ramus supplies muscle and skin of the back while ventral ramus supplies everything else. Cervical enlargement: As the spine houses a greater amount of neurons at levels related to nerves of the upper limb (brachial plexus, C5-T1), these segments of the spine increase in thickness Lumbosacral enlargement: (spinal cord segments L2-S3) Associated with parts of the spine that house neurons associated with lower limb innerva on. Extends from vertebral level T10 to taper down to the conus medullaris with maximal enlargement opposite T12. Lecture 7 Nervous system can be understood in four subdivisions: Soma c nerves relate to the skin, body wall and skeletal muscle Visceral nerves relate to hollow organs Autonomics are either sympathe c or parasympathe c. Most sympathe cs are routed through the paravertebral or sympathe c chain, which is suspended from the ventral rami of each level by white (heavily myelinated onramp) and gray (lightly myelinated o ramp) rami communicans. ti ti ti tt ff fi ti fi ti ti fi ti ti fi ti ti ti Soma c sensory nerve distribu on over skin can be understood in terms of either cutaneous/sensory eld or dermatome. The former follows the path of a speci c named nerve, irrespec ve of root value (i.e., the levels of the spinal cord from which its bers take origin). The la er represents all por ons of ti fi skin supplied by nerve bers from a speci c vertebral level, irrespec ve of which nerve branch carries those bers to their respec ve des na ons. Lecture 8 Manubrium Sternum Xiphoid process Costal car lages ti fi Ribs ti ti Thoracic vertebrae ti fi ti fi The thoracic skeleton is comprised of: The parts of a rib are the head, neck, tubercle, body Ribs ar culate with thoracic vertebrae at ar cular facets at the vertebral body and transverse process. The head of each rib ar culates with two vertebrae whereas the tubercle of the rib ar culates with one transverse process. The body of the rib has a groove called the subcostal groove that admits the intercostal vein, artery, and nerve (in that order from superior to inferior). The distal ends of ribs 1-10 ar culate with costal car lages. Ribs 11 and 12 are “ oa ng ribs” that do not have any car laginous a achments. Blood supply of thoracic wall There are anterior and posterior intercostal arteries. Posterior intercostal arteries are direct branches from the thoracic aorta. Anterior intercostal arteries are direct branches from the internal thoracic arteries. Remember branching pa ern: Aor c arch  brachiocephalic arterial trunk (on right side)  subclavian artery  internal thoracic artery  anterior intercostal artery ~~Anterior and posterior intercostal arteries anastomose with each other. Serves a as a poten al route of collateral bloodlow Intercostal muscles func on between the ribs. These are: External intercostals- Origin on superior rib, inser on on inferior rib (hands-in-pocket orienta on). Pulls inferior rib upward toward superior rib. Important in forced inspira on (expanding thorax). Example: slurping forcefully through straw. Internal and innermost intercostals- Origin on inferior rib, inser on on superior rib (hands-out-of-pocket orienta on). Pulls superior rib downward toward inferior rib. Important in forced expira on (depressing the thorax). Example: Blowing out birthday candles. Addi onal notes: ti ti ti ti ti fl ti ti ti ti ti fi ti ti tt ti ti ti ti fl ti ti ti ti tt During quiet respira on, the lungs do not ll completely the thorax. This leaves minute spaces such as the costodiaphragma c recess which are empty spaces containing only minute amounts of serous uid. The breast is comprised of fat lobules res ng between suspensory ligaments (of Cooper) and suspended from an axillary tail. Both males and females possess lac ferous glands, ducts, sinuses. Lympha c drainage of the breast is 75% to axillary lymph nodes and 25% to sternal lymph nodes. Lectures 9-14 Axial skeleton includes Skull Hyoid bone Vertebrae Ribs Manubrium Sternum Xiphoid Process Clavicle Scapula Humerus Radius Ulna Carpal bones (Scaphoid, Lunate, Triquetrum, Pisiform, Trapezium, Trapezoid, Capitate, Hamulus) Metacarpals Phalanges ti ti ti Bones of the upper limb include The only bony ar cula on between appendicular skeleton of upper limb and axial skeleton is at the manubrioclavicular joint. Muscles tend to occur in groups and compartments. In compartments of the arm and forearm, muscles tend to have similar func on, blood supply, and innerva on. Blood supply to upper limb muscles comes from branches of subclavian artery, axillary artery, and brachial artery. Innerva on Innerva on of upper limb muscles is via the brachial plexus. The plexus is divided into: Roots (really just ventral rami of C5-T1 spinal nerves) Trunks Divisions Cords Nerves Cords are located in the axillary region and are named based on their posi on rela ve to axillary artery. Lateral cord-Con nues as the musculocutaneous nerve; gives contribu on to median nerve Medial cord-Con nues as the ulnar nerve; gives contribu on to the median nerve Posterior cord-Con nues as the radial nerve and axillary nerve. Any injury to posterior cord would impact muscles innervated by either radial or axillary nerves (see above for details on deltoid and teres minor muscles). Nerves around extrinsic back, pectoral region and scapula: - Long thoracic nerve to serratus anterior muscle is from C5-C7 roots of brachial plexus (i.e., from ventra rami of spinal nerves from those levels) -Dorsal scapular nerve (supplying rhomboid major and minor muscles) originate from C5 root of brachial plexus (i.e., ventral ramus from spinal nerve of that level) ti ti ti ti ti ti ti ti ti ti ti ti ti -Suprascapular nerve is from Superior trunk of brachial plexus -Medial and lateral pectoral nerves are from medial and lateral cords of the brachial plexus, respec vely -Upper and lower subscapular nerves (to subscapularis muscle) originate from posterior cord Nerves of arm and forearm: Musculocutaneous nerve pierces coracobrachialis and supplies anterior arm muscles (coracobrachialis, biceps brachii, brachialis) Distal to the anterior compartment of arm, it con nues as the lateral cutaneous nerve of forearm, thus the “cutaneous” part of its name. Radial nerve con nues through the triangular interval (see above) and down through the radial groove to supply all extensor/posterior muscles of the arm and forearm, including the brachioradialis muscle. It splits into a deep branch (and becomes posterior interosseous nerve supplying most posterior forearm muscles a er piercing the supinator muscle) and a super cial branch supplying skin over posterior wrist and lateral side of dorsal hand (with small patch over skin covering thenar muscles). Note that when a midsha humeral fracture occurs, a condi on called “wrist drop” may result wherein extensors of the elbow, wrist, and digits no longer receive innerva on from radial nerve or its branches. Ulnar nerve provides no innerva on in arm but does supply forearm and hand muscles. It gets there by travelling around the medial epicondyle of the humerus, where it is super cial and can be easily injured. From there, it supplies: two medial forearm muscles ( exor carpi ulnaris and the medial half of the exor digitorum profundus muscle belly) most intrinsic hand muscles (that is, muscles whose origin and inser on are both within the hand). The remainder are innervated by the median nerve. has a super cial branch providing sensory innerva on to medial side of hand on dorsal and palmar surfaces. ti fl ti fi fl fl ti fi ti ti ti fi ti ti Deep branch, called the anterior interosseous nerve, supplies most muscles in deep layer of anterior forearm (lateral half of exor digitorum profundus muscle belly, exor pollicis longus, pronator quadratus). This branch travels with anterior interosseous vein and artery. fl fl Most muscles in super cial layer of anterior forearm (pronator teres, exor carpi radialis, palmaris longus, exor digitorum super cialis) ft fi ft ti fl fi Median nerve provides no innerva on in arm but does supply: Travels through carpal tunnel before supplying thenar muscles via its recurrent branch ( exor pollicis brevis, abductor pollicis brevis, opponens pollicis) and rst two lumbricals. Ulnar nerve deep branch supplies all other intrinsic hand muscles. Provides sensa on on lateral side of palmar hand. Arterial supply of upper limb Brachial artery divides, gives o deep artery of arm (or profunda brachii artery) that travels with radial nerve in radial/spiral groove Brachial artery divides into radial artery and ulnar artery. Radial artery travels down lateral forearm, through anatomical snu box between extensor pollicis longus and brevis tendons, and inserts into the hand posteriorly between two heads of the 1st dorsal interosseous muscle. The radial artery gives rise to the deep arterial arch in the hand which supplies most intrinsic hand muscles. Ulnar artery gives o common interosseous branch shortly a er bifurca ng from brachial artery. This common interosseous branch gives rise to the posterior and anterior interosseous arteries lying on either side of the interosseous membrane. A er giving o common interosseous branch, ulnar artery con nues with ulnar nerve running under cover of exor carpi ulnaris muscle and travels through ulnar tunnel to reach hand, forming super cial arterial arch of hand. There is variable amount of anastomosis with deep arterial arch from radial artery. Lectures 16-17 Autonomic nerves can be divided into sympathe c and parasympathe c nerves. Autonomic nerves func on as a two-neuron system with a neuron in the central nervous system and a secondary cell body outside the central nervous system (a ganglion). -Parasympathe c innerva on of the body from the neck to the le colic exure (i.e., transi on from transverse to descending colon) are supplied by branches of the vagus nerve. Distal to the transverse colon, pelvic splanchnics provide parasympathe c innerva on. The vagus nerve is a cranial nerve with its primary cell body in the brain stem whereas pelvic splanchnic nerves have their primary cell bodies in S2-S4 por ons of spinal cord. All parasympathe c nerves have their secondary cell bodies on or close to the e ector organ. Thus, they can be described as having a long preganglionic and short postganglionic path. ti fl ti fl ti ti ff ft ti fi ft ti ff fl ti ti ti ff ti ft fi ff ti ti ff ti ti ti ti ti ti ti ti Sympathe c innerva on of the body is provided by nerves with their primary cell bodies in the T1-L2 por ons of spinal cord. However, there is varia on in where their secondary cell bodies are located. All sympathe c innerva on to sweat glands and erector pili muscle in skin, smooth muscle in arteries, and thoracic organs have their secondary cell bodies in the sympathe c/paravertebral chain of ganglia, where they synapse before heading toward e ector organ. The sympathe c chain extends from the three cervical ganglia to the one ganglion impar in the coccygeal region that unites le and right sides. An excep on to this system is the sympathe c innerva on of organs of the abdomen, pelvis, and perineum. Sympathe c nerves to these regions also have primary cell bodies in lateral horns of spine but their secondary cell bodies are not in the sympathe c chain. Instead, they pass through the chain without synapsing to instead synapse at pre-aor c ganglia over the abdominal aorta. Each collec on of ganglia are named a er the aor c branch around which they are clustered. Greater splanchnic nerve combines pre-ganglionic bers from T5-T9 Lesser splanchnic nerve combines pre-ganglionic bers from T10-T11 levels Least splanchnic nerve arises from T12 por on of spinal cord These three thoracic splanchnic nerves synapse at celiac, aor corenal, and superior mesenteric ganglia. The postsynap c nerves travel along arterial branches to reach e ector organ. ti ti ft ti ff ti ti ti fi fi ti ff ti ti ti ti ft fi ti fi ti Lumbar splanchnic nerves have their primary cell bodies in lateral horns of T11 or T12 to L2 spinal levels. These preganglionic bers travel to inferior mesenteric ganglia, where they synapse. Postsynap c/ postganglionic bers travel to lower gut (descending colon and more distal gut structures) and pelvic/ perineal organs. Embryology Stages of meiosis Meiosis Stage I and Meiosis Stage II. NOTE: Nondisjunc on at Prophase I leads to trisomy disorders such as Down’s Syndrome (Trisomy 21) Before ovula on, meiosis I completed: now 2o oocyte and rst polar body At ovula on, 2o oocyte reaches metaphase II Metaphase II commences immediately a er ovula on A er fer liza on: fi ti ti Cytotrophoblast begins growing into the syncy otrophoblast ft ti ti ti ti ti ft These cells columns are the primary chorionic villi These are the rst stage of the chorionic villi of the placenta. Mature villi are dis nguished from forma on of villar capillaries: Syncy otrophoblast produces human chorionic gonadotropin (hCG), which maintains: o Spiral artery development in myometrium o Forma on of syncy otrophoblast o Sync otrophoblast responsible for breaking down endometrial lining locally for implanta on of embryo hCG is released into maternal blood o Basis for early pregnancy tests (end of Week 2) To review: 1st week – fer liza on, morula, blastocyst, Implanta on of blastocyst around day 6, hCG secre on 2nd week – Bilaminar germ disc (week 2 has 2 layers) epiblast and hypoblast 3rd week – Trilaminar germ disc (week 3 has 3 layers)- FORMATION OF PRIMITIVE STREAK- ectoderm, intraembryonic mesoderm and endoderm. The process is known as gastrula on ti ti ti ti ti ti fi ti ti ti ti ti ti Three layers of trilaminar embryo are endoderm, mesoderm, and ectoderm. They are subdivided: -Surface ectoderm (epidermis, hair, nails) vs Neurectoderm (Central and peripheral nerve ssue) -Paraxial medodern (skeletal muscle) vs Intermediate mesoderm (urinary system) -Endoderm (Epithelial lining of major organs) Notochord Does not give rise to vertebral column Forms central axis for developing embryo, Induces forma on of neural tube and provides central column around which vertebral bodies will form. Fate: Nucleus pulposus of intervertebral disc Neural Tube Neural tube communicates with amnio c cavity through neuropores Caudal por on of neural tube is narrow, forms spinal cord Cranial por on is broad, forms brain ti ti ti ti ti fi Spina bi da results from incomplete or incorrect closure of the caudal neuropore