Embryology Chapter 2: Tissues and Organ Systems

Lamina Propria

Underlying connective tissue layer beneath epithelial tissue that supplies it with nourishment.

Pseudostratified Epithelium

Appears multi-layered, but all cells remain in contact with the basal lamina.

Stratified Epithelium

Composed of several cell layers, with only the basal layer contacting the basal lamina.

Keratinized Epithelium

Epithelial layer characterized by flat surface cells.

Prenatal Epithelial Development

By 11 to 12 weeks, the single ectodermal cell layer thickens into four layers.

Skeletal Muscle

Voluntary, striated, and multinucleate muscle enabling body movement and posture.

Muscles of Mastication

Arise from the 1st pharyngeal arch and are innervated by CN V (Trigeminal).

Muscles of Facial Expression

Arise from the 2nd pharyngeal arch and are innervated by CN VII (Facial).

Pharyngeal Constrictor Muscles

Located in the throat; arise from 3rd/4th pharyngeal arches; innervated by CN IX and X.

Tongue Muscles

Formed from occipital myotomes; innervated by CN V, VII, IX, X, and XII.

Smooth Muscle

Involuntary, non-striated muscle controlling vascular diameter, secretion, and GI peristalsis.

Cardiac Muscle

Involuntary, binucleate muscle forming the muscular wall of the heart.

Integumentary System

Body's largest organ; protects against foreign materials, eliminates heat, and excretes waste.

Skeletal System Function

Provides structural framework and produces blood cells via bone marrow.

Neural System

Body's control center utilizing CNS, afferent sensory pathways, and efferent motor pathways.

Vascular System

Delivers oxygen and nutrients, returns carbon dioxide, and functions in clotting and immunity.

Lymphatic System

Consists of lymphoid organs and lymphocytes that recognize and destroy foreign invaders.

Respiratory System

Exchanges oxygen and carbon dioxide; includes nasal chambers that warm, moisten, and filter air.

Digestive System

Ingests, transforms, and absorbs food nutrients while excreting solid waste.

Urinary System

Regulates blood volume/pressure and urine composition; secretes erythropoietin.

Endocrine System

Secretes hormones to regulate metabolism, growth, reproduction, and stress responses.

Reproductive System

Produces gametes and sex hormones to coordinate reproduction and embryonic development.

Special Senses

Includes vision, hearing/balance, smell (olfactory epithelium), and taste (taste buds).

Central Nervous System (CNS)

The body's control center, consisting of the brain and spinal cord.

Forebrain (Embryonic)

Forms the cerebral hemispheres, including the frontal, temporal, and occipital lobes.

Midbrain (Embryonic)

Acts as a pathway from the cerebral cortex; region where cranial nerve V develops.

Hindbrain (Embryonic)

Forms the pons and the cerebellum.

Afferent (Sensory) System

Carries sensory information from the peripheral nervous system to the CNS.

Efferent (Motor) System

Conveys motor response signals from the CNS out to muscles and glands.

Autonomic System Divisions

Divided into the sympathetic division (increases activity) and parasympathetic division (decreases activity).

Neurons

Neural cells composed of a cell body, axon, and dendrites that receive and conduct impulses.

Neuroglial Cells

The supporting cells of the nervous system arising from neuroepithelial cells.

Simple Epithellum

Consists of a single layer of cells