What are the two ways ventricles are filled with blood during Phase 1 of the cardiac cycle?
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Passive filling (70-80%) and atrial contraction (20-30%).
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What are the two ways ventricles are filled with blood during Phase 1 of the cardiac cycle?
Passive filling (70-80%) and atrial contraction (20-30%).
What mechanical event produces the first heart sound (S1), often described as "Lub"?
The closing of the AV (Atrioventricular) valves.
What mechanical event produces the second heart sound (S2), often described as "Dub"?
The closing of the semilunar valves (pulmonary and aortic).
What is the primary action of the temporalis muscle?
Elevates the mandible (closes the jaw).
Which muscle is primarily responsible for forearm supination (the "holding a bowl of soup" analogy)?
Biceps brachii.
How does the closure timeline of the posterior fontanelle compare to the anterior fontanelle?
The posterior fontanelle (2-3 months) closes significantly earlier than the anterior fontanelle (12-18 months).
Which gland is housed within the hypophyseal fossa of the sella turcica?
The pituitary gland (hypophysis).
What anatomical feature is exclusive to cervical vertebrae?
The presence of a transverse foramen (for the vertebral artery).
What is the primary identifier for vertebrae C3 through C6?
A bifid (split) spinous process.
A fracture at the surgical neck of the humerus puts which nerve at the greatest risk?
Axillary nerve.
Which landmark on the radius serves as the attachment point for the biceps brachii muscle?
Radial tuberosity.
What is the large, dense internal section of the temporal bone that contains structures like the internal acoustic meatus?
The Petrous part.
What major vessel passes through the jugular foramen of the temporal bone?
Internal jugular vein.
Which opening is located specifically between the styloid and mastoid processes of the temporal bone?
The stylomastoid foramen.
Which two bones form the hard palate?
The palatine process of the maxillary bone (anteriorly) and the horizontal plate of the palatine bone (posteriorly).
What are the two major foramina of the mandible? Where is each located?
The mental foramen (on the anterior surface) and the mandibular foramen (on the inner/medial side).
What is the name of the non-articulating, sharp projection on the superior aspect of the mandibular ramus?
The coronoid process.
Which part of the mandible articulates to form the Temporomandibular Joint (TMJ)? With which bone does it articulate?
The mandibular condyles; they articulate with the mandibular fossa of the temporal bone.
What is the primary physical characteristic of lumbar vertebrae L1-L5 compared to other vertebrae? Why?
They have very thick and robust vertebral bodies (centrums) designed for bearing significant weight.
What are the two components of an intervertebral disc?
The annulus fibrosus (tough outer ring) and the nucleus pulposus (gel-like inner core).
Distinguish between the vertebral foramen and the intervertebral foramen in the lumbar region.
Vertebral foramen (central opening for the spinal cord) and intervertebral foramen (lateral openings between adjacent vertebrae for spinal nerves).
How is the sacrum formed?
Fusion of five individual sacral vertebrae.
What joint is essential for pelvic stability? Which specific surfaces form it?
Sacroiliac joint; it is formed by the auricular surface of the sacrum and the auricular surface of the ilium.
On which surface of the scapula does the subscapularis muscle originate?
The subscapular fossa.
Which anatomical feature of the scapula allows passage for the suprascapular nerve?
The suprascapular notch.
Which pelvic notch is converted into a foramen by ligaments to allow the sciatic nerve to exit the pelvis?
The Greater Sciatic Notch.
What is the name of the largest foramen in the human body, found in the pelvis?
The Obturator Foramen.
What is the small pit on the head of the femur that serves as an attachment site for ligaments?
The fovea capitis.
What are the two prominent projections on the proximal femur for muscle attachment?
The greater and lesser trochanters.
What is the name of the ridge running down the posterior shaft of the femur?
The linea aspera.
What small tubercle is located just above the medial epicondyle of the femur?
The adductor tubercle.
What is the prominent bump on the anterior tibia that serves as the attachment site for the patellar ligament?
The tibial tuberosity.
Which part of the fibula articulates at the proximal tibiofibular joint? With which tibial landmark does it articulate?
The head of the fibula articulates with the lateral condyle of the tibia.
What is the shared dual function of the sternocleidomastoid and scalene muscles?
Assisting in neck flexion and forceful inhalation.
Name two posterior neck muscles that primarily act to extend the neck.
Splenius capitis and Semispinalis capitis.
Which muscle of the posterior neck is responsible for elevating the scapula?
Levator scapulae.
What is the primary action of the platysma muscle?
Depresses the mandible.
What are the three primary actions of the pectoralis major muscle?
Flexion, adduction, and medial rotation of the arm at the shoulder.
Which major shoulder muscle is responsible for arm abduction?
The deltoid muscle (specifically the middle head).
What is the specific role of the supraspinatus muscle in arm movement?
Initiating arm abduction.
What is the primary function of the infraspinatus muscle?
Lateral (external) rotation of the shoulder.
Name the three actions performed by the latissimus dorsi.
Extension, medial rotation, and adduction of the shoulder.
Which single-headed muscle is the primary flexor of the forearm at the elbow?
Brachialis.
On which bony landmark does the triceps brachii muscle insert?
The olecranon process of the ulna.
What is the action of the brachioradialis muscle?
Flexion of the forearm at the elbow (especially in a mid-position).
Which muscle is known as the "smiling muscle" because it draws the angle of the mouth upward and backward?
The zygomaticus major.
What is the name of the sphincter muscle around the eye responsible for blinking and squinting?
The orbicularis oculi.
Which sphincter muscle surrounds the lips and is used to close or pucker the mouth?
The orbicularis oris.
Which muscle protrudes the lower lip, often associated with an expression of sadness or pouting?
The mentalis.
What is the name of the muscle that pulls the angle of the mouth downward, creating a frown?
The depressor anguli oris (triangularis).
Which muscle is responsible for pulling the eyebrows upward?
The occipitofrontalis (frontal belly).
What connective tissue structure connects the frontal and occipital bellies of the occipitofrontalis?
The galea aponeurotica (epicranial aponeurosis).
Which deep forearm flexor is responsible for flexing the digits?
The flexor digitorum profundus.
What is the common origin for many muscles in the extensor compartment of the forearm?
The lateral epicondyle of the humerus.
What is the common origin for many muscles in the flexor compartment of the forearm?
The medial epicondyle of the humerus.
Which forearm muscle is specifically responsible for flexing the thumb (pollex)?
The flexor pollicis longus.
Which forearm muscle is responsible for extending and adducting the wrist?
The extensor carpi ulnaris.
List the four muscles of the thenar eminence (thumb side of the hand).
Opponens pollicis, Abductor pollicis brevis, Flexor pollicis brevis, and Adductor pollicis brevis.
List the three muscles of the hypothenar eminence (little finger side of the hand).
Opponens digiti minimi, Abductor digiti minimi, and Flexor digiti minimi.
What is the primary function of the opponens pollicis?
Opposition of the thumb (moving thumb to touch other fingers).
During which phase of the cardiac cycle are all four heart valves closed and ventricular pressure is rising?
Isovolumetric Contraction.
What are the peak pressures reached in the left and right ventricles during the Isovolumetric Contraction phase?
Approximately 120 mmHg in the left ventricle and 25 mmHg in the right ventricle.
What specific pressure relationship causes the semilunar valves to open during Ventricular Ejection?
When ventricular pressure exceeds arterial pressure (Pventricle > Parterial).
What is the term for the volume of blood remaining in the ventricles after contraction?
End Systolic Volume (ESV).
What is the dicrotic notch, and what causes it?
A brief rise in aortic pressure caused by the backflow of blood snapping the aortic semilunar valve shut.
What is the function of the olfactory foramina in the cribriform plate?
Passage for the olfactory nerve (Cranial Nerve I).
What is the primary function of the crista galli of the ethmoid bone?
Attachment point for the falx cerebri (a fold of the dura mater).
Which two bones articulate to form the nasal septum?
Ethmoid bone and vomer bone.
Which two pairs of nasal conchae are part of the ethmoid bone?
Superior and middle nasal conchae.
What is the primary function of fontanelles in the fetal skull?
To facilitate skull expansion for brain growth and allow for passage through the birth canal.
What are the paired "fang-like" projections on the lesser wings of the sphenoid bone?
Anterior clinoid processes.
Which parts of the sphenoid bone serve as attachment sites for muscles of mastication?
Pterygoid processes (lateral and medial plates).
List the four paranasal sinuses.
Frontal, Maxillary, Sphenoid, Ethmoid.
Which suture separates the two parietal bones?
Sagittal suture.
Which suture separates the parietal bones from the occipital bone?
Lambdoid suture.
What is the small area of the frontal bone located between the eyebrows?
Glabella.
Which structures of the occipital bone articulate with the first cervical vertebra (C1)?
Occipital condyles.
Which canal in the temporal bone allows for the passage of the vestibulocochlear nerve?
Internal acoustic meatus.
Which foramen is found between the styloid and mastoid processes of the temporal bone?
Stylomastoid foramen.
Which two bony processes meet to form the zygomatic arch?
Temporal process of the zygomatic bone and zygomatic process of the temporal bone.
What is the midline fusion point of the mandible?
Mandibular symphysis.
What is the name of the prominent anterior projection at the superior margin of the sacrum's body?
Sacral promontory.
What anatomical feature forms the median sacral crest?
Fusion of the spinous processes of the sacral vertebrae.
Which surface of the sacrum articulates with the ilium to form the sacroiliac joint?
Auricular surface.
What are the three specific facets on a rib that articulate with a thoracic vertebra?
Superior and inferior facets on the head; tubercle facet.
Which ribs are classified as "vertebrosternal" because they attach directly to the sternum?
Ribs 1-7 (True Ribs).
Which ribs are classified as "vertebrochondral" because they attach indirectly to the sternum?
Ribs 8, 9, and 10.
Which ribs have no anterior attachment at all?
Ribs 11 and 12.
List the three parts of the sternum from superior to inferior.
Manubrium, Body, Xiphoid Process.
Which two notches are found on the manubrium of the sternum?
Jugular notch and clavicular notches.
Which two muscles of mastication are primarily responsible for elevating the mandible?
Masseter and Temporalis.
What is the action of the medial and lateral pterygoid muscles?
Grinding and protrusion of the jaw.
Which muscle pulls the corner of the mouth laterally, contributing to expressions of grimness?
Risorius.
Which group of lateral neck muscles assists in both neck flexion and forceful inhalation?
Scalenes (Anterior, Middle, Posterior).
Which large, superficial muscle extends the neck and elevates the scapula?
Trapezius.
What is the general function of the suprahyoid muscles?
Elevate the hyoid bone (crucial for swallowing).
What is the general function of the infrahyoid muscles?
Depress the hyoid bone.
Which muscle acts as an antagonist to the teres minor and infraspinatus regarding shoulder rotation?
Teres Major.
Which rotator cuff muscle is responsible for medial (internal) rotation of the shoulder?
Subscapularis.
Which small muscle in the shoulder region is a synergist for arm flexion and adduction?
Coracobrachialis.
What is the shared action of the triceps brachii and the anconeus?
Extension of the forearm at the elbow.
Which muscle in the extensor compartment of the forearm actually performs elbow flexion?
Brachioradialis.
Which muscle is the primary extender of digits 2-5?
Extensor Digitorum.
Which forearm flexor is located deep to the palmaris longus and flexes the digits?
Flexor Digitorum Superficialis.
Which two muscles are responsible for protraction of the scapula?
Serratus Anterior and Pectoralis Minor.
Which intercostal muscles are used for forced exhalation?
Internal intercostals.
Which abdominal muscle does NOT perform trunk flexion?
Transversus abdominis.
What is the name of the midline connective tissue where the abdominal muscles insert?
Linea alba.
Describe the fiber directions of the external and internal oblique muscles.
External oblique: downward and forward; Internal oblique: upward and forward.
Which muscle is commonly referred to as the "six-pack"?
Rectus abdominis.
Match the mechanical events of the heart to the EKG waves: Atrial contraction, Ventricular contraction, and Ventricular relaxation.
P (atrial depolarization), QRS (ventricular depolarization), T (ventricular repolarization).
What mechanical event happens first during Phase 1 of the cardiac cycle when atrial pressure exceeds ventricular pressure?
Passive ventricular filling (~80%).
What two mechanical events cause the S1 and S2 heart sounds, respectively?
Closure of AV valves (S1) and Closure of Semilunar valves (S2).
What two openings in the sphenoid bone allow passage for nerves to the orbit?
Optic canal (optic nerve) and superior orbital fissure (cranial nerves/vessels).
What is the saddle-shaped depression in the sphenoid bone?
Sella turcica.
Explain the relationship between the ethmoid bone and the eye sockets (orbits).
It articulates with the nasal cavity through air cells and forms the medial orbital walls.
Which three lines on the occipital bone serve as muscle attachment points?
Superior, median, and inferior nuchal lines.
What is the large opening in the base of the skull for the spinal cord?
Foramen magnum.
What is the large bony projection behind the ear on the temporal bone?
Mastoid process.
What is the "pen-like" projection on the temporal bone?
Styloid process.
Which bone is specifically referred to as the cheekbone?
Zygomatic bone.
What is the name of the bony ridge on the maxilla and mandible that supports the teeth?
Alveolar process.
What is the name of the hole located just below the orbit on the maxilla?
Infraorbital foramen.
What horizontal lines on the sacrum mark the fusion of the five sacral vertebrae?
Transverse ridges.
What are the wing-like lateral expansions on either side of the sacrum?
Ala of the sacrum.
What is the name for the narrow, inferior tip of the sacrum?
Apex of the sacrum.
Which landmark on a rib helps determine if it is from the right or left side? Which way does it point?
Costal groove; it always points downwards.
Explain the articulation between a rib tubercle and a vertebra.
The tubercle of the rib articulates with the transverse process of the thoracic vertebra.
Which neck muscle is the antagonist to the splenius capitis for neck flexion/extension?
Sternocleidomastoid (SCM).
Which muscle's name literally translates to its action of lifting the shoulder blade?
Levator scapulae.
Which suprahyoid muscle has two "bellies" and can also depress the mandible if the hyoid is fixed?
Digastric (anterior and posterior bellies).
Which infrahyoid muscle originates on the scapula and inserts on the hyoid?
Omohyoid (superior and inferior bellies).
Which three-headed shoulder muscle performs abduction, flexion, and extension?
Deltoid.
Which rotator cuff muscle is found on the anterior side of the scapula?
Subscapularis.
Which two muscles are synergists for lateral (external) rotation of the shoulder?
Infraspinatus and Teres Minor.
Which two muscles are synergists for medial rotation and adduction of the shoulder?
Teres Major and Latissimus Dorsi.
Which two muscles are the extension antagonists to the pectoralis major's flexion of the arm?
Teres major and Latissimus dorsi.
What are the two origin sites for the heads of the biceps brachii?
Long head (supraglenoid tubercle) and Short head (coracoid process).
What is the insertion site for the brachialis muscle?
Coronoid process of the ulna.
What are the names of the two forearm muscles responsible for wrist extension?
Extensor carpi radialis longus and Extensor carpi radialis brevis.
List the three superficial muscles in the anterior (flexor) compartment of the forearm that perform wrist flexion.
Flexor carpi radialis, Palmaris longus, and Flexor carpi ulnaris.
Which muscle is the synergist to the pectoralis minor for scapular protraction?
Serratus anterior.
Which small muscle lies directly under the clavicle and depresses it?
Subclavius.
Which tiny muscle tenses the linea alba?
Pyramidalis.
Which abdominal muscle has fibers that run horizontally?
Transversus abdominis.
