Structural Organization of the Human Body and Body Systems

Flashcards providing terminology definitions across cellular levels, tissues, organ systems, skeletal anatomy, joint structures, muscular mechanics, and nervous system divisions based on the lecture transcript.

Anatomy

The branch of science concerned with the bodily structure of humans, animals, and other living organisms, especially as revealed by dissection and the separation of parts.

Physiology

The branch of biology that deals with the normal functions of living organisms and their parts, including the way in which a living organism or bodily part functions.

Cytoplasm

A major cell section made up of a jelly-like fluid called cytosol and other structures surrounding the nucleus.

Cytoskeleton

A network of long fibers that forms the cell's structural framework, determines cell shape, participates in cell division, and directs organelle movement.

Endoplasmic Reticulum (ER)

An organelle that helps process molecules created by the cell and transports them to specific destinations inside or outside the cell.

Golgi Apparatus

An organelle that packages molecules processed by the endoplasmic reticulum to be transported out of the cell.

Lysosomes and Peroxisomes

Organelles that act as the recycling center of the cell by digesting foreign bacteria, removing toxic substances, and recycling worn-out cell components.

Mitochondria

Complex organelles containing their own genetic material that convert energy from food into a form usable by the cell.

Nucleus (Cell)

The cell's command center that houses deoxyribonucleic acid (DNA) and directs the cell to grow, mature, divide, or die.

Plasma Membrane

The outer lining of the cell that separates it from its environment and allows materials to enter and leave.

Ribosomes

Organelles that process genetic instructions to create proteins, floating freely in cytoplasm or attached to the endoplasmic reticulum.

Mitosis

A form of vegetative cell division in eukaryotes resulting in daughter cells that are genetically identical to the parent cell.

Meiosis

A form of reproductive cell division in eukaryotes that reduces the chromosome number by half to generate haploid gametes.

Areolar Tissue

Connective tissue characterized by small open spaces, containing fibroblasts, white blood cells, mast cells, and fibers in a ground material that binds skin to underlying muscles.

Adipose Tissue

Connective tissue found beneath skin in subcutaneous regions and around internal organs that stores energy as fat, cushions, and insulates the body.

Reticular Connective Tissue

Tissue composed of reticular cells (fibroblasts) and reticular fibers that provides a structural scaffolding for cells in lymph nodes and bone marrow.

Epithelial Tissue

Protective tissue consisting of closely packed cells that covers the outer surface of the body and lines internal organ surfaces.

Integumentary System

Organ system consisting of skin, hair, nails, and exocrine glands that regulates temperature, protects the body, eliminates waste, and helps make vitamin D.

Skeletal System

System composed of bones, joints, and associated cartilages that supports the body, protects organs, aids movement, stores lipids/minerals, and produces blood cells.

Muscular System

System referring to skeletal muscle tissue attached to bones that maintains posture, produces heat, and assists in body movements.

Cardiovascular System

System consisting of blood, heart, and blood vessels that transports oxygen, nutrients, and waste products while regulating fluid acidity and temperature.

Diaphysis

The tubular shaft running between the proximal and distal ends of a long bone, containing a hollow medullary cavity filled with yellow marrow.

Epiphysis

The expanded portion at either end of a long bone filled with spongy tissue and red marrow.

Metaphysis

The region where the diaphysis joins the epiphysis, containing the epiphyseal plate of hyaline cartilage in growing bones.

Periosteum

A fibrous membrane binding the outer surface of a bone, housing blood vessels, nerves, and lymph vessels that nourish compact bone.

Endosteum

A delicate membranous lining of the medullary cavity where bone growth, repair, and remodeling occur.

Osteoblasts

Cells responsible for bone formation that produce new bone matrix composed of bone collagen and other proteins.

Osteoclasts

Large cells originating from bone marrow that dissolve and break down existing bone tissue during resorption.

Parathyroid Hormone

A hormone secreted when blood calcium levels fall below normal to stimulate osteoclasts to break down bone and restore calcium levels.

Axial Skeleton

The group of bones forming the central axis of the body to support and protect the head, neck, and trunk, including the skull, vertebral column, and thoracic cage.

Appendicular Skeleton

The section of the skeleton that includes the shoulder girdle, upper limbs, pelvic girdle, and lower limbs.

Fibrous Joint

A joint lacking a synovial cavity, bound together by collagen-rich thick irregular connective tissue, permitting little to no movement.

Cartilaginous Joint

A joint lacking a synovial cavity in which cartilage binds the articulating bones together, permitting little or no movement.

Synovial Joint

A freely movable joint distinguished by the presence of a fluid-filled synovial cavity between articulating bones.

Agonist

Also called the prime mover, this muscle provides the major force required to execute a desired action or movement.

Antagonist

A muscle that opposes the movement of the agonist, relaxing while the prime mover contracts.

Synergist

A muscle that stabilizes a joint around which movement takes place by preventing unnecessary motions to aid the agonist.

Fixator

A muscle that stabilizes the origin of the agonist and the joint it spans to ensure effective agonist function.

Creatine Phosphate

An energy-rich molecule unique to muscle fibers that provides ATP for the initial $15$\text{ seconds} of muscle contraction.

Myoglobin

An oxygen-binding protein contained exclusively in muscle fibers that binds oxygen when abundant and releases it when limited.

Cerebrum

The largest region of the brain, composed of two hemispheres, responsible for initiating movement, perception, decision-making, thinking, and emotion.

Cerebellum

The posterior brain region located at the back of the ear that coordinates voluntary muscle movements, posture, and balance.

Brain Stem

The central brain area comprising the midbrain, pons, and medulla, controlling vital involuntary functions like breathing, cardiac rate, and swallowing.

Autonomic Nervous System (ANS)

A visceral efferent component of the peripheral nervous system that innervates smooth muscle, cardiac muscle, and glands automatically and continuously.

Somatic Nervous System

The part of the peripheral nervous system responsible for voluntary, conscious motor control over skeletal muscles.