Anatomical Directional Terms Quiz and Flashcards

Posterior (or dorsal) refers to the back or direction towards the back of the body
Superior (or cranial) refers to a position above or higher than another part of the body
Inferior (or caudal) refers to a position below or lower than another part of the body
Lateral refers to the side or direction towards the side of the body
Medial refers to the middle or direction towards the middle of the body
Proximal refers to a position in a limb that is nearer to the point of attachment or the trunk of the body
Distal refers to a position in a limb that is farther from the point of attachment or the trunk of the body
Superficial refers to a position closer to the surface of the body
Deep refers to a position farther from the surface of the body

Two major cavities: thoracic cavity and abdominal pelvic cavity
Separated by the diaphragm
Act to protect vital functions and allow organs to expand without disturbing other surrounding tissue

A cell can be divided into three main parts: plasma (cell) membrane, cytoplasm, and nucleus
Organelles within the cytoplasm:
- Membranous organelles: covered with their own plasma membrane, isolating them from the cytosol
- Non-membranous organelles: no membrane, in direct contact with the cytosol
Nucleus:
- Contains genetic material (DNA)
- Regulates cell activities
- Surrounded by a double membrane (nuclear envelope)
- Contains nucleolus, involved in ribosome synthesis
Mitochondria:
- Powerhouse of the cell
- Site of cellular respiration
- Generates ATP (adenosine triphosphate) energy
- Has its own DNA (mitochondrial DNA)
Endoplasmic Reticulum (ER):
- Rough ER: studded with ribosomes, involved in protein synthesis and processing
- Smooth ER: synthesizes lipids, detoxifies drugs and toxins
Golgi Apparatus:
- Modifies, sorts, and packages proteins and lipids
- Forms vesicles for transport within the cell or secretion outside the cell
Lysosomes:
- Contain digestive enzymes
- Break down cellular waste, foreign substances, and damaged organelles
- Recycling center of the cell
Ribosomes:
- Site of protein synthesis
- Can be free in the cytoplasm or bound to the rough ER

Cells vary greatly in size and shape, with around 200 different types in the human body
Cell signaling and recognition:
- Integral proteins and carbohydrates on the cell surface are involved in cell signaling and recognition
- Receptor proteins bind to specific signaling molecules, triggering cellular responses
Cell surface carbohydrates participate in cell recognition and immune responses
Cellular transport:
- Integral proteins facilitate the transport of ions and molecules across the membrane
- Channel proteins form pores for passive transport, allowing ions to move down their concentration gradient
- Carrier proteins undergo conformational changes to transport specific molecules against their concentration gradient (active transport)
Cell adhesion and support:
- Membrane proteins and carbohydrates mediate cell-cell adhesion and interactions with the extracellular matrix
- This adhesion is crucial for tissue formation, structural integrity, and stability of multicellular organisms

Small, uncharged, lipid-soluble molecules can cross the lipid bilayer from ECF to ICF by simple diffusion
Pinocytosis is a process where the cell sips up fluid and dissolved nutrients
Phagocytosis is a process where the cell engulfs large particles or debris
Tonicity:
- Isotonic solutions have the same solute concentration as inside the cell
- Hypertonic solutions have a higher concentration of solutes compared to inside the cell
- Hypotonic solutions have a lower concentration of solutes compared to inside the cell

Direct communication: juxtacrine (near) gap junction, contains two connexons per gap junction, allows cell-to-cell communication, direct small molecule, ions, glucose, very fast, gap junction in heart, brain, and smooth muscles
Five main types of indirect cell-to-cell communication

Cellularity and tissue organization:
- Epithelial tissues consist of closely packed cells with minimal extracellular matrix
- Form continuous sheets that cover body surfaces, line cavities and organs, and create glands
High mitotic activity: epithelial cells have a high rate of mitosis, allowing for rapid replacement and repair of damaged cells
Interaction with environments: epithelium interacts with both internal and external environments, acts as a barrier, protects underlying tissues from mechanical damage, pathogens, and dehydration, and facilitates the exchange of nutrients and wastes between body compartments
Basement membrane: separates the epithelium from underlying connective tissue, facilitates the exchange of substances between epithelial cells and blood vessels
Specializations: epithelial cells exhibit various specializations to perform specific functions effectively, examples include cilia, which move substances along the cell surface, and microvilli, which increase surface area for absorption or secretion