Human Anatomy Quiz: Body Systems Overview

Lymphatic System Structures and Functions

• Lymph Vessels: Thin-walled tubes carrying lymph from tissues to larger lymphatic vessels.
• Lymph Fluid: Clear, colorless fluid containing tissue fluid waste products.
• Lymph Nodes: Contain white blood cells producing antibodies to fight infection. They swell during infection.

Central Nervous System (CNS)

• Brain: Primary center for regulating and coordinating body activities. Each brain region controls specific bodily functions.
• Spinal Cord: Carries nerves affecting limbs and lower body. It's the pathway for impulses traveling to and from the brain.

Sensory vs. Motor Nerves

• Sensory Nerves: Carry impulses from skin or sense organs towards the brain and spinal cord.
• Motor Nerves: Carry impulses away from the brain and spinal cord towards muscles and glands.

Respiratory System Structures and Functions

• Nose: Air enters the body through nostrils, passing through the nasal cavity.
• Pharynx: Air travels from the nasal cavity to the pharynx (throat).
• Epiglottis: Acts as a lid covering the larynx, preventing food and liquid from entering the respiratory system.
• Larynx: Voice box, protected by cartilage.
• Trachea: Extends from the neck to the chest, in front of the esophagus. Divides into bronchi.
• Alveolar Sacs: Site of air exchange.

Histology

• The study of tissue structure and function at the microscopic level.

Congenital Conditions

• Present at birth. Caused by genetic, non-genetic factors, or a combination. Can be structural or functional anomalies (e.g., metabolic disorders, hearing defects).

Cleft Palate vs. Cleft Lip

• Cleft Palate: Opening or split in the roof of the mouth. Often includes a split in the upper lip (cleft lip).
• Cleft Lip: Opening in the upper lip, not affecting the palate.

Prenatal Development Periods

• Preimplantation Period: First week, from sperm penetration (fertilization) to zygote formation (46 chromosomes).
• Embryonic Period: Week 2 to 8, critical for organ and structure development.
• Fetal Period: Week 9 to birth.

Tooth Development Stages

• Initiation Stage: Weeks 6-7, ectoderm gives rise to oral epithelium. First tooth to form is the mandibular central incisor.
• Bud Stage: Week 8, cells proliferate.
• Cap Stage: Week 10, cells proliferate forming a cap-like enamel organ.
• Bell Stage: Weeks 11-12, four cell types are present. Enamel organ forms enamel, dental papilla forms dentin and pulp.
• Appositional (Calcification): Hardening of tooth structure by calcium deposition. Enamel (95% hydroxyapatite), Dentin (70% hydroxyapatite), Cementum (65%).
• Eruption Stage: Tooth movement into functional position. Root elongation pushes the tooth to the oral surface.

Odontogenesis

• Tooth formation from embryonic cells, growth, and eruption into the mouth.

Ameloblast

• Cell forming enamel.

Cementoblast

• Cell forming cementum.

Odontoblast

• Cell forming dentin.

Calcification (Hydroxyapatite)

• Mineral compound making up bone and teeth.

Tissues of the Tooth

• Enamel: Hardest material in the body, covering the crown.
• Dentin: Main body of the tooth, extending almost the entire length of the tooth, covered by enamel on the crown.
• Cementum: Covers the root of the tooth. Suspends tooth in the bony socket with periodontal ligament fibers.
• Pulp: Connective tissue, blood vessels, and nerves.

Primary and Permanent Eruption Patterns

• Primary Teeth: Eruption from 6 months to 6 years. Begins with mandibular central incisors, ends with first permanent mandibular molar.
• Permanent Teeth: Begins around 12 years with the first molars ("six-year molars").

Gingival Structures

• Mucogingival Junction (MGJ): Where attached gingiva meets alveolar mucosa.
• Interdental Papilla: Gingiva between teeth.
• Free Gingiva (Unattached Gingiva, Marginal Gingiva): Where free gingiva meets attached gingiva.
• Sulcus: Space between the tooth and free gingiva.

Parts of the Tongue

• Dorsum: Tongue's upper surface.
• Body of Tongue: Anterior 2/3.
• Root of Tongue: Posterior 1/3, located in the pharynx.
• Ventral: Undersurface of the tongue, connected to the floor of the mouth.

Linea Alba

• White ridge of raised tissue extending horizontally where maxillary and mandibular teeth meet.

Fordyce Granules

• Normal, small yellowish elevations on the buccal mucosa and lips.

Frenum Abnormalities

• Labial Frenum: Too thick, causing a diastema between teeth #8 and #9.
• Ankyloglossia: Lingual frenum too short.

Muscles of the Head and Neck

• Sternocleidomastoid Muscle (SCM): One of many neck muscles. Has dual innervation and multiple functions.
• Trapezius Muscle: Large back muscle extending from the occipital bone to the thoracic vertebrae and scapula.

Salivary Glands

• Parotid: Secretes into the oral cavity through Stensen's duct.
• Submandibular: Inferior to mylohyoid muscle, secretes into the oral cavity through Wharton's duct.
• Sublingual: Salivary duct carrying saliva from the sublingual gland.

Xerostomia

• Dry mouth. Can increase dental decay and cause speech and chewing problems.

Sinuses

• Maxillary Sinus: Located within the maxilla. Part of the paranasal sinuses (air-filled spaces in the skull).
• Frontal Sinus: Mucus production, lightens skull bones, provides sound resonance.

TMJ (Temporomandibular Joint)

• Mandibular Fossa: Concave part of the temporal bone on the skull.
• Articular Disc: Cushion between the mandibular fossa and condyle.

Roots (Number of Roots in Teeth)

• Maxillary 1st Premolar: Two roots.
• Maxillary 2nd Premolar: One root.
• Canines and Incisors: Usually one root.
• All Mandibular Premolars: Single rooted.
• Maxillary Molars: Three roots (MB, DB, palatal), trifurcation. Wisdom tooth roots tend to fuse.
• Mandibular 1st Molars: Two roots, usually the same length.
• Mandibular 2nd Molars: Two roots.
• Mandibular 3rd Molars (Wisdom Teeth): Roots usually fused.

Anatomic vs. Clinical Crown

• Anatomic Crown: Includes the incisal/occlusal third, middle third, and cervical third.
• Clinical Crown: Area between the crown and root. Cervical third is where enamel meets cementum.

Trigeminal Nerve (CN V)

• Has three divisions (branches):
  • Ophthalmic Division
  • Maxillary Division (V2)
  • Mandibular Division (V3)

Maxillary and Mandibular Nerves

• Maxillary Division (V2):
  • PSA (Posterior Superior Alveolar Nerve): Innervates maxillary molars, the MB root of the maxillary 1st molar, and buccal mucosa.
  • MSA (Middle Superior Alveolar Nerve): Innervates premolars, the MB root of the maxillary 1st molar, and buccal mucosa.
  • ASA (Anterior Superior Alveolar Nerve): Innervates anterior teeth and labial mucosa.
  • Infraorbital Nerve (IO): Innervates anterior teeth and soft tissues.
  • Greater Palatine Nerve (GP): Innervates posterior palatal tissue (not teeth).
  • Nasopalatine Nerve: Passes through the incisive foramen, supplies palatal mucoperiosteum of maxillary anterior teeth.
• Mandibular Division (V3):
  • Inferior Alveolar Nerve (IA): Subdivides into mylohyoid nerve, mental nerve, incisive nerve, and small dental nerves. Supplies molars, premolars, alveolar process, and periosteum.
  • Mental Nerve: Exits mental foramen, supplies soft tissues (gingiva, buccal mucosa of premolars/anteriors, lip, chin).
  • Incisive Nerve: Continuation of the inferior alveolar nerve, supplies roots of premolars/anterior teeth.