ANA Preliminary

What are the structural and physiological functions of bone?

Bone provides structural support, protection for organs, facilitates movement by serving as attachment sites for muscles, stores minerals like calcium and phosphorus, and houses bone marrow for blood cell production.

What distinguishes bone tissue from other types of connective tissues?

Bone tissue is characterized by its hard matrix, high mineral content (mainly calcium phosphate), and the presence of osteocytes embedded within a mineralized matrix, which contrasts with the softer structures found in other connective tissues.

What molecule confers hardness/stiffness to bone?

Hydroxyapatite, a crystalline structure composed of calcium and phosphate, confers hardness and stiffness to bone.

What type of loading does this stiffness resist?

The stiffness of bone primarily resists compressive loading.

How does the biological form of this molecule differ from the geological form?

The biological form of hydroxyapatite contains organic components and is synthesized by living cells, while the geological form is a mineral that occurs naturally without biological processes.

What molecule confers resiliency to bone?

Collagen confers resiliency to bone, allowing it to absorb shock and resist tension.

What type of loading does this toughness resist?

The toughness provided by collagen primarily resists tensile loading.

In what sense is bone similar to plywood and why?

Bone is similar to plywood in that both materials have a layered structure that provides strength and resilience in multiple directions, allowing them to withstand various forces.

How do bone cell types differ, structurally and functionally? Where are they found?

Bone cells include osteoblasts (bone formation), osteocytes (maintenance), and osteoclasts (bone resorption). Osteoblasts are found on the bone surface, osteocytes are embedded within the bone matrix, and osteoclasts reside in Howship's lacunae on bone surfaces.

How do the different types of bone cells function together to maintain bone tissue?

Osteoblasts produce new bone matrix, osteocytes help regulate bone health and respond to mechanical stress, while osteoclasts break down old bone, maintaining a balance between bone formation and resorption.

What is compact bone? What are its characteristics?

Compact bone (cortical bone) is dense and forms the outer layer of bones, characterized by a tightly packed structure that provides strength and support.

What is trabecular bone? What are its characteristics?

Trabecular bone (cancellous bone) is spongy and porous, found inside bones, characterized by a network of struts and plates that provide structural support while reducing weight.

Describe how the blood supply to compact bone and trabecular differs.

Compact bone receives blood supply through the Haversian system, with central canals, while trabecular bone receives blood supply from surrounding marrow and does not have the Haversian system.

How are compact and trabecular bone distributed/organized in the skeletal system?

Compact bone is found on the outer layer of bones, providing strength, while trabecular bone is located within the interiors, providing support and reducing weight.

What is lamellar bone?

Lamellar bone is mature bone organized in layers, known for its strength and stability.

What is woven bone? How do they differ structurally? Why does the body produce both?

Woven bone is immature bone with a random collagen fiber arrangement, while lamellar bone has a regular, organized structure. Woven bone forms during growth or repair, while lamellar bone is the mature bone.

Know your osteon! What are the primary gross features/morphology of a typical long bone?

A typical long bone consists of the diaphysis (shaft), epiphyses (ends), articular cartilage on joint surfaces, and a medullary cavity filled with bone marrow.

How do periosteum and endosteum differ? In what ways are they similar?

The periosteum is the outer fibrous layer surrounding bones, while the endosteum lines the inner surfaces of bone; both are connective tissues involved in bone growth and repair.

Describe the distribution of compact and trabecular bone in a typical long bone.

A typical long bone has a thick layer of compact bone in the diaphysis and trabecular bone in the epiphyses.

What are the basic features of a typical long bone?

Basic features include the diaphysis, epiphysis, articular surfaces, periosteum, endosteum, and medullary cavity.

Bony feature terminology.

Common bony features include tuberosity (large bump), process (projection), fossa (depression), and condyle (rounded end).

How do long bones ‘grow’ – lengthen and widen?

Long bones lengthen at the growth plates (epiphyseal plates) via endochondral ossification and widen through appositional growth involving periosteal activity.

What is the axial skeleton? What bones comprise the axial skeleton?

The axial skeleton includes the skull, vertebral column, and rib cage, providing protection and support for the central axis of the body.

Cranium: neurocranium and splanchnocranium.

The neurocranium protects the brain and includes bones like the frontal, parietal, and occipital bones, while the splanchnocranium includes facial bones such as the maxilla and mandible.

What bones comprise neurocranium?

The neurocranium comprises the frontal, parietal, temporal, occipital, sphenoid, and ethmoid bones.

What bones comprise splanchnocranium?

The splanchnocranium comprises the maxilla, mandible, zygomatic, nasal, palatine, and others associated with the face.

What are the three cranial fossae?

The three cranial fossae are the anterior, middle, and posterior cranial fossae, each housing different parts of the brain.

What bones comprise each cranial fossa?

The anterior cranial fossa includes the frontal and ethmoid bones; the middle cranial fossa includes the sphenoid and temporal bones; the posterior cranial fossa includes the occipital and some temporal bones.

What is the Temporomandibular joint (TMJ)?

The TMJ is the joint connecting the jaw (mandible) to the skull, allowing movements such as opening and closing the mouth.

What types of movements does the Temporomandibular joint allow?

The TMJ allows hinge movements, gliding movements, and some degree of rotation.

How does the neurocranium of the fetus/neonate differ from that of the adult?

The neurocranium of the fetus/neonate is softer with fontanelles to allow for cranial shape changes during birth and growth, while the adult skull is fully fused and harder.

What are the structural features of a typical vertebra?

A typical vertebra includes a vertebral body, neural arch, spinous process, transverse processes, and vertebral foramen.

What are the different types of vertebrae? Where is each type of vertebra located?

The vertebrae types include cervical (neck), thoracic (upper back), lumbar (lower back), sacral (pelvis), and coccygeal (tailbone).

What are the unique features of each type of vertebrae that allow you to distinguish one type from another?

Cervical vertebrae have transverse foramina; thoracic vertebrae have facets for rib articulation; lumbar vertebrae have larger bodies for weight support.

Describe the curvature of the human spine. – how is the shape accomplished?

The human spine has cervical and lumbar lordosis (inward curves) and thoracic and sacral kyphosis (outward curves), shaped by vertebral structure and muscle adaptations.

What type of curvature (kyphosis or lordosis) characterizes each region of the spine?

Cervical and lumbar regions exhibit lordosis, while thoracic and sacral regions exhibit kyphosis.

How does the spine of a neonate differ with respect to curvature from that of an adult?

Neonates have a single primary kyphotic curve, while adults develop a cervical and lumbar curve as they mature and begin to stand.

What is an intervertebral disk? What are the structural components of an intervertebral disk?

An intervertebral disk is a fibrocartilaginous structure between vertebrae, composed of a nucleus pulposus (gel-like center) and annulus fibrosus (outer fibrous ring).

What are the properties of each disk component? How is the disk organized?

The nucleus pulposus provides shock absorption, while the annulus fibrosus resists tensile forces; the disk is organized concentrically.

What bones comprise the thorax? How many ribs are present?

The thorax comprises the sternum and 12 pairs of ribs, totaling 24 ribs.

What are the different rib types?

Rib types include true ribs (1-7), false ribs (8-10), and floating ribs (11-12).

What is the sternum and where is it located?

The sternum, or breastbone, is located in the center of the chest, connecting the ribs via cartilage.

What is the appendicular skeleton? What bones comprise the appendicular skeleton?

The appendicular skeleton includes all the limb bones and girdles (pectoral and pelvic) that facilitate movement.

What bones comprise the pectoral girdle?

The pectoral girdle comprises the clavicle and scapula.

What bones comprise the pelvic girdle?

The pelvic girdle comprises the ilium, ischium, and pubis.

How do the pectoral and pelvic girdles differ?

The pectoral girdle is more mobile with a lighter structure for arm movement, while the pelvic girdle is sturdier for weight-bearing and locomotion.

What are the primary structural differences between the male and female pelves?

The female pelvis is broader and shallower with a wider pelvic inlet and angle to accommodate childbirth, while the male pelvis is narrower and taller.

What are the four joint classes (based on histological structure)? Can you recognize them? Provide an example or two?

The four joint classes are fibrous (e.g., sutures), cartilaginous (e.g., intervertebral joints), synovial (e.g., knee), and bony (e.g., sacroiliac joint).

What are the three joint classes (based on range of motion)? Can you recognize them? Provide and example of each.

The joint classes based on range of motion are synarthroses (immovable, e.g., sutures), amphiarthroses (slightly movable, e.g., pubic symphysis), and diarthroses (freely movable, e.g., shoulder joint).

Most joints in the appendicular skeleton are synovial joints. Describe a synovial joint – its structures/organization.

A synovial joint includes a joint capsule, synovial membrane, synovial fluid, articular cartilage on bone ends, and ligaments for stability.

Discuss the similarities and differences between the shoulder and hip joints (consider motions/range of motion/stability and mobility, joint integrity, joint surfaces/shapes and soft tissues).

The shoulder joint is highly mobile, allowing extensive movement, while the hip joint is more stable but has a more limited range of motion due to its deeper socket.

Discuss the similarities and differences between the elbow and knee joints (consider motions/range of motion/stability and mobility, joint integrity, joint surfaces/shapes and soft tissues).

The elbow joint allows for hinge movements, providing stability and a limited range of motion, while the knee allows for flexion and rotation, making it less stable but more mobile.

Why is blood classified as a connective tissue?

Blood is classified as a connective tissue because it consists of cells (formed elements) suspended in a liquid extracellular matrix (plasma), which functions to connect and support other tissues in the body.

What functions are performed by the formed elements of blood?

The formed elements of blood include erythrocytes (transport oxygen and carbon dioxide), leukocytes (immune response and protection), and platelets (blood clotting).

How does erythrocyte structure affect erythrocyte function?

Erythrocytes are biconcave in shape, which increases their surface area for gas exchange, enables flexibility to pass through capillaries, and allows for optimal hemoglobin loading and unloading of oxygen and carbon dioxide.

How is blood produced?

Blood is produced through a process called hemopoiesis, which occurs primarily in the red bone marrow, involving the differentiation of stem cells into various blood cell types.

What is blood viscosity?

Blood viscosity refers to the thickness or stickiness of blood, which affects its flow properties through vessels.

Why do we consider the viscosity and osmolarity of blood to be important properties?

Viscosity and osmolarity are important because they influence blood flow, pressure, nutrient transport, and the overall hydration status of cells in the body.

What are the histological differences/signatures of leukocytes that allow us to identify each?

Leukocytes can be identified based on their size, nucleus shape, and the presence of specific granules; for example, neutrophils have multi-lobed nuclei, while lymphocytes have large, round nuclei.

What is the difference between fibrin and fibrinogen?

Fibrinogen is a soluble plasma protein that is converted into fibrin, an insoluble protein that forms the fibrous mesh in blood clots during coagulation.

What are the protective functions of blood?

Blood provides protection by transporting immune cells (leukocytes) to sites of infection, forming blood clots to prevent excessive bleeding, and containing antibodies that attack pathogens.

What are the transport functions of blood?

Blood transports oxygen, carbon dioxide, nutrients, hormones, and waste products throughout the body, supporting cellular functions and homeostasis.

What are the regulatory functions of blood?

Blood regulates bodily functions, including body temperature, pH balance, and fluid volume by distributing heat and buffering acids and bases.

What does hemopoiesis mean?

Hemopoiesis refers to the formation and development of blood cells from stem cells in the bone marrow.

How is blood formed?

Blood is formed through hemopoiesis, where hematopoietic stem cells differentiate into various blood cell types in the red bone marrow.

Can you describe the size, shape, and contents of an erythrocyte?

An erythrocyte is a small, biconcave disc approximately 7-8 micrometers in diameter, containing hemoglobin for oxygen transport and lacking a nucleus and organelles.

What is the function of hemoglobin?

Hemoglobin binds to oxygen in the lungs and carries it to tissues, while also transporting a portion of carbon dioxide back to the lungs for exhalation.

What are the different types of anemia?

Different types of anemia include iron-deficiency anemia, aplastic anemia, hemolytic anemia, sickle cell anemia, and pernicious anemia, each characterized by reduced red blood cell count or hemoglobin function.

What is the overall function of leukocytes?

The overall function of leukocytes is to protect the body against infections and foreign invaders by forming part of the immune response.

How does the body control bleeding?

The body controls bleeding through vascular spasm, platelet plug formation, and blood coagulation (clotting) processes.

What is the function of platelets?

Platelets, or thrombocytes, play a crucial role in hemostasis by adhering to damaged blood vessels, aggregating to form plugs, and releasing chemicals that promote clotting.

How do the four chambers of the heart differ structurally and functionally?

The right atrium receives deoxygenated blood from the body, the right ventricle pumps it to the lungs, the left atrium receives oxygenated blood from the lungs, and the left ventricle pumps it to the body; the left ventricle has thicker walls than the right for greater pumping force.

Explain the pattern of blood flow through the heart.

Blood flows from the body into the right atrium, through the right ventricle to the lungs for oxygenation, back to the left atrium, then into the left ventricle, and finally out to the body through the aorta.

What’s wrong with the idea that arteries always carry “red” blood and veins carry “blue” blood?

While arteries typically carry oxygenated (red) blood away from the heart and veins carry deoxygenated (blue) blood back to the heart, the pulmonary arteries and veins are exceptions, carrying deoxygenated blood from the heart to the lungs and oxygenated blood from the lungs to the heart, respectively.

What are the mechanisms of valve openings and closings within the heart?

Heart valves open and close in response to pressure changes; when atrial pressure exceeds ventricular pressure, atrioventricular (AV) valves open; when ventricular pressure exceeds arterial pressure, semilunar valves open to allow blood flow.

How does the earliest fetal heart differ from the adult heart?

The earliest fetal heart has shunts (foramen ovale and ductus arteriosus) that bypass pulmonary circulation, enabling blood flow directly from the right atrium to the left atrium and from the pulmonary artery to the aorta, since the lungs are not yet functioning.

What are the names of the sulci around the heart and which vessels occupy them?

The major sulci include the coronary sulcus (coronary arteries and veins) and the anterior and posterior interventricular sulci (interventricular arteries).

Describe the anatomical position of the heart?

The heart is located in the mediastinum, between the lungs, tilted to the left side, with the base oriented superiorly and posteriorly, and the apex directed inferiorly and anteriorly.

What is the mediastinum?

The mediastinum is the central compartment of the thoracic cavity that contains the heart, trachea, esophagus, and major blood vessels, separating the thoracic organs into right and left sides.

From inside-out, what are the layers of the heart and the coverings of the heart?

The layers of the heart include the endocardium (inner), myocardium (muscle layer), and epicardium (outer). The heart is covered by the pericardium, which consists of the fibrous pericardium and serous pericardium.

Why is there serous fluid in the pericardial cavity?

Serous fluid in the pericardial cavity reduces friction between the heart and surrounding structures during heartbeats, allowing smooth movement.

Which side of the heart acts as the pulmonary pump?

The right side of the heart acts as the pulmonary pump, sending deoxygenated blood to the lungs for oxygenation.

Which side of the heart acts as the systemic pump?

The left side of the heart acts as the systemic pump, delivering oxygenated blood to the rest of the body.

What are vessel tunica and what are their structural and functional differences and properties?

Vessel tunica refers to the three layers of blood vessel walls: tunica intima (inner, smooth lining), tunica media (middle, muscular layer for contraction), and tunica externa (outer, protective layer); their proportions vary among vessel types, affecting their function.

What are the different types of arteries?

The types of arteries include elastic arteries (e.g., aorta), muscular arteries (e.g., radial artery), and arterioles (smallest arteries regulating blood flow).

How do the vessel tunica differ among the types of arteries?

Elastic arteries have a thicker tunica media with more elastin; muscular arteries have more smooth muscle for regulation; arterioles have a thinner tunica media that allows for vasoconstriction and vasodilation.

What are the different types of capillaries? How does their structure reflect their function?

There are three types of capillaries: continuous (restrictive, found in muscles and skin), fenestrated (more permeable, found in kidneys and intestines), and sinusoidal (highly permeable with large openings, found in liver and spleen), reflecting their specific functions in tissue exchange.

How do arteries and veins generally differ both structurally and functionally?

Arteries have thicker walls with more smooth muscle and elastic tissue to handle high pressure and carry oxygenated blood (except pulmonary arteries), while veins have thinner walls, larger lumens, and valves to prevent backflow, transporting deoxygenated blood back to the heart.

Why are valves present in veins but not in arteries?

Valves are present in veins to prevent the backflow of blood due to low pressure and gravity; arteries do not require valves as the blood is propelled away from the heart under high pressure.

What is the Circle of Willis (cerebral arterial circle) and what is its function?

The Circle of Willis is a circular arterial structure at the base of the brain that provides collateral circulation, ensuring consistent blood flow to the brain even if one artery becomes occluded.

Can you trace the flow of blood from the right atrium of the heart to the lungs and back to the left atrium?

Deoxygenated blood flows from the right atrium to the right ventricle, then through the pulmonary arteries to the lungs for oxygenation, returning via the pulmonary veins to the left atrium (not directly back to the right atrium).

From where do the signals to vasoconstrict arise?

Signals for vasoconstriction arise from the sympathetic nervous system, particularly during situations needing increased blood pressure or reduced blood flow to certain areas.

What layer of the vessel receives the vasoconstriction signal?

The smooth muscle layer of the tunica media receives the vasoconstriction signal, allowing the vessel to constrict or dilate.

In the Systemic Circuit which contains more blood – arteries or veins – or are they equal?

In the systemic circuit, veins contain more blood than arteries, approximately 65-70% of total blood volume, due to their larger capacity and thinner walls.

What factors determine resistance in a vessel?

Resistance in a vessel is determined by vessel diameter, length, and blood viscosity; smaller diameters and longer lengths increase resistance, while greater viscosity also increases it.

What percentage of blood is normally contained within the heart, arteries, capillaries, and veins?

Approximately 7% of blood is held in the heart, 10% in arteries, 5% in capillaries, and 65-70% in veins.

Can you identify the major arteries of the Systemic Circuit and the areas and organs that are supplied by each?

Major arteries include: aorta (supplies the body), carotid arteries (supply the brain), subclavian arteries (supply the arms), renal arteries (supply the kidneys), and femoral arteries (supply the legs).

Can you identify the major veins of the Systemic Circuit and the areas and organs that are drained by each?

Major veins include: superior vena cava (drains the upper body), inferior vena cava (drains the lower body), jugular veins (drain the head and neck), renal veins (drain the kidneys), and femoral veins (drain the legs).

Can you describe the major cardiovascular changes that occur at birth and explain the functional significance?

At birth, the lungs inflate, changing blood flow and shutting down fetal shunts (foramen ovale and ductus arteriosus), allowing blood to flow through the lungs for oxygenation instead of bypassing it, establishing normal adult circulation.

Why are valves found in veins but not in arteries?

Valves in veins prevent backflow, essential for returning deoxygenated blood to the heart against gravity; arteries transport blood away from the heart under high pressure and do not require one-way valves.