Exam #2 T&D BIOLOGY
TISSUES AND HOMEOSTASIS
Anatomy
The study of the body's structure
Physiology
The study of the body's functioning
Organism
An individual living thing
Tissues
A cellular organizational level between cells and a complete organ. A tissue is an ensemble of similar cells and their extracellular matrix from the same origin that together carry out a specific function. Organs are then formed by the functional grouping together of multiple tissues.
Organ
A group of tissues in a living organism that have been adapted to perform a specific function. In higher animals, organs are grouped into organ systems.
Organ System
A group of organs that work together to perform one or more functions. Each does a particular job in the body, and is made up of certain tissues.
Osteogenic Cells
Undifferentiated stem cells that differentiate to form osteoblasts in the tissue that covers the outside of bone.
Osteoblasts
Immature bone cells that are involved in synthesizing new bone. They develop into osteocytes, or mature bone cells.
Osteocytes
Star-shaped bone cells that make up the majority of bone tissue. They are the most common cells in mature bone.
Osteoclasts
Very large, multinucleated cells responsible for the breakdown of bones through resorption.
Leukocytes
White blood cells; type of blood cell that help the body fight infection and disease
Monocytes
Make up about five per cent of leukocytes. They engulf and destroy (phagocytize) pathogens in tissues.
Eosinophils
Compose about two per cent of leukocytes. They attack larger parasites and set off allergic responses.
Basophils
Make up less than one per cent of leukocytes. They release proteins called histamines that are involved in inflammation.
Lymphocytes
Make up about 30 per cent of leukocytes. They include B cells and T cells. B cells produce antibodies against nonself antigens, and T cells destroy virus-infected cells and cancer cells.
Neutrophils
The most numerous white blood cells, making up about 62 per cent of leukocytes. They phagocytize single-celled bacteria and fungi in the blood.
Epithelial Tissue
Tissue which lines the outer surfaces of organs and blood vessels throughout the body, as well as the inner surfaces of cavities in many internal organs. An example is the epidermis, the outermost layer of the skin. There are three principal shapes of epithelial cell: squamous, columnar, and cuboidal.
Connective Tissue
One of the four basic types of tissue, connective tissue is found in between other tissues everywhere in the body, including the nervous system and generally forms a framework and support structure for body tissues and organs.
Fibrous Connective Tissue
Characterized by a matrix which is flexible and is made of protein fibres including collagen, elastin and possibly reticular fibres.
Fibroblasts
A cell in connective tissue which produces collagen and/or other protein fibers.
Loose Fibrous Connective Tissue
Composed of a loose and disorganized weave of collagen and elastin fibres, creating a tissue that is thin and flexible, yet still tough, found in membranes and surrounding blood vessels and most body organs.
Dense Fibrous Connective Tissue
Composed of a dense mat of parallel collagen fibres and a scattering of fibroblasts, creating a tissue that is very strong, forms tendons and ligaments, which connect bones to muscles and/or bones to neighbouring bones.
Supportive Connective Tissue
Exhibits the defining feature of connective tissue in that it is a scattering of cells in a non-cellular matrix, the matrix is solid- either bone or cartilage.
Cartilage
Supportive connective tissue that provides a smooth surface for the movement of bones at joints. Contains cells called chondrocytes.
Chondrocyte
A cell which has secr eted the matrix of cartilage and become embedded in it.
Osteocytes
A bone cell, formed when an osteoblast becomes embedded in the matrix it has secreted.
Fluid Connective Tissue
A form of connective tissue in which the matrix is in a liquid state. Examples include blood and lymph.
Muscular Tissue
A soft tissue that composes muscles in animal bodies, and gives rise to muscles' ability to contract.
Skeletal Muscle
Voluntary, striated muscle that is attached to bones of the skeleton and helps the body move.
Smooth Muscle
An involuntary, nonstriated muscle that is found in the walls of internal organs such as the stomach.
Peristalsis
A distinctive pattern of smooth muscle contractions that propels foodstuffs distally through the esophagus and intestines.
Cardiac Muscle
Involuntary, striated muscle found only in the walls of the heart; also called myocardium.
Nervous Tissue
A specialized tissue found in the central nervous system and the peripheral nervous system. It consists of neurons and supporting cells called neuroglia.
Basal Cells
Stem cells in the stratum basal layer that divide to form all the keratinocytes of the epidermis
Basal Cell Carcinoma
Most common type of skin cancer that occurs in basal cells of the epidermis, may appear as a pearly or waxy bump.
Squamous Cells
Flattened, keratin-filled cells in the upper layers of the epidermis.
Squamous Cell Carcinoma
Second most common type of skin cancer that occurs in squamous cells of the epidermis, may appear as a firm, red nodule, or as a flat lesion with a scaly or crusty surface.
Melanocytes
The melanin-producing cells in the stratum basale of the epidermis.
Melanoma
Rarest type of skin cancer that occurs in the melanocytes of the epidermis, may appear as a mole that changes in size, feel, or color, a mole that bleeds, a large brown spot on the skin sprinkled with darker specks, a small lesion with an irregular border and parts that appear red, white, blue, or blue-black, or a dark lesion on the palms, soles, fingertips, toes, or mucous membranes.
Integumentary System
The body system comprised of skin and its appendages acting to protect the body from various kinds of damage, such as loss of water or damages from outside.
Skeletal System
The body system composed of bones and cartilage and performs the following critical functions for the human body: supports the body. The skeletal system facilitates movement, protects internal organs, and produces blood cells.
Muscular System
The body system responsible for the movement of the human body. Attached to the bones of the skeletal system are about 700 named muscles that make up roughly half of a person's body weight. Each of these muscles is a discrete organ constructed of skeletal muscle tissue, blood vessels, tendons, and nerves.
Nervous System
The highly complex body system of an animal that coordinates its actions and sensory information by transmitting signals to and from different parts of its body. The nervous system detects environmental changes that impact the body, then works in tandem with the endocrine system to respond to such events.
Endocrine System
The body system which acts as a chemical messenger system comprising feedback loops of the hormones released by internal glands of an organism directly into the circulatory system, regulating distant target organs. In humans, the major endocrine glands are the thyroid gland and the adrenal glands.
Cardiovascular System
Refers to the body system consisting of the heart, blood vessels and the blood. Blood contains oxygen and other nutrients which your body needs to survive. The body takes these essential nutrients from the blood.
Lymphatic System
A body system consisting of a network of tissues and organs that help rid the body of toxins, waste and other unwanted materials. The primary function of the lymphatic system is to transport lymph, a fluid containing infection-fighting white blood cells, throughout the body.
Respiratory System
The body system responsible for taking in oxygen and expelling carbon dioxide. The primary organs of the respiratory system are the lungs, which carry out this exchange of gases as we breathe.
Digestive System
A body system including a series of hollow organs joined in a long, twisting tube from the mouth to the anus. The hollow organs that make up the GI tract are the mouth, esophagus, stomach, small intestine, large intestine, and anus. The liver, pancreas, and gallbladder are the solid organs of the digestive system.
Excretory System
The body system responsible for the elimination of wastes produced by homeostasis. There are several parts of the body that are involved in this process, such as sweat glands, the liver, the lungs and the kidney system. From there, urine is expelled through the urethra and out of the body.
Urinary System
The body system part of the excretory system that produces, stores and eliminates urine, the fluid waste excreted by the kidneys. The kidneys make urine by filtering wastes and extra water from blood. Urine travels from the kidneys through two thin tubes called ureters and fills the bladder.
Reproductive System
The body system by which humans reproduce and bear live offspring.
Body Cavity
A fluid-filled space inside the body that holds and protects internal organs.
Ventral Cavity
A major human body cavity at the anterior (front) of the trunk that contains such organs as the lungs, heart, stomach, intestines, and internal reproductive organs.
Thoracic Cavity
A body cavity, part of the ventral cavity, in the chest that holds the lungs and heart.
Abdominopelvic Cavity
Body cavity, part of the ventral cavity, that fills the lower half of the trunk and holds the kidneys and the digestive and reproductive organs.
Dorsal Cavity
A major human body cavity that includes the head and the posterior (back) of the trunk and holds the brain and spinal cord.
Cranial Cavity
A cavity, part of the dorsal cavity. that fills most of the upper part of the skull and contains the brain.
Spinal Cavity
A long, narrow body cavity inside the vertebral column that runs the length of the trunk and contains the spinal cord.
Homeostasis
The ability of an organism to maintain constant internal conditions despite external changes.
Negative Feedback Loop
A control mechanism that serves to reduce an excessive response and keep a variable within its normal range (e.g. body temperature regulation and controlling blood glucose levels).
Positive Feedback Loop
A control mechanism that serves to intensify a response until an endpoint is reached (e.g. blood clotting and childbirth).
SKELETAL SYSTEM
Skeletal System
The body system composed of bones and cartilage and performs the following critical functions for the human body: supports the body. The skeletal system facilitates movement, protects internal organs, and produces blood cells.
Cartilage
Supportive connective tissue that provides a smooth surface for the movement of bones at joints. Contains cells called chondrocytes.
Ligaments
A band of dense fibrous connective tissue that holds bones together.
Axial Skeleton
A division of the skeleton that includes the skull, rib cage, and vertebral column.
Appendicular Skeleton
The bones of the upper and lower limbs, shoulder girdle, and pelvic girdle.
Hematopoiesis
The process in which red blood cells, white blood cells, and platelets are produced by red bone marrow.
Osteocalcin
An endocrine hormone secreted by bone cells that helps to regulate blood glucose and fat deposition.
Skull
The part of the human skeleton that provides a bony framework for the head and includes bones of the cranium and face.
Cranium
The upper part of the skull that encloses and protects the brain.
Vertebral Column
A flexible column of vertebrae that connects the trunk to the skull and encloses the spinal cord; also called spine or backbone.
Vertebrae
One of 33 small bones that make up the vertebral column.
Rib Cage
A bony “cage” enclosing the thoracic cavity and consisting of the ribs, thoracic vertebrae, and sternum.
Pectoral Girdle
Paired clavicles (collar bones) and scapulas (shoulder blades) that together form the shoulders and attach the arms to the trunk; also called shoulder girdle.
Pelvic Girdle
Paired, fused bones (ilium, pubis, and ischium) that form the hips and attach the legs to the trunk.
Bone
A rigid organ that constitutes part of the vertebrate skeleton in animals.
Bone Tissue
The hard connective tissue in bones that consists mainly of mineralized collagen matrix; also called osseous tissue.
Compact Bone Tissue
A type of bone tissue that is smooth and dense and makes up the outer layer of bones.
Spongy Bone Tissue
A light-weight, porous inner layer of bone that contains bone marrow.
Bone Marrow
A soft connective tissue in spongy bone that produces blood cells.
Periosteum
A tough, fibrous membrane that covers the outer surface of bones.
Osteoblasts
A type of bone cell that makes and mineralizes bone matrix.
Osteocytes
A type of bone cell that helps regulate the formation and breakdown of bone tissue.
Osteoclasts
A type of bone cell that breaks down bone, dissolves its minerals, and releases them into the blood.
Osteogenic Cells
A type of stem cell that can divide and differentiate to form new bone cells.
Long Bones
A hard, dense bone that provide strength, structure, and mobility. The thigh bone (femur) is an example of a long bone. A long bone has a shaft and two ends.
Short Bones
Bones that are as wide as they are long. Their primary function is to provide support and stability with little to no movement.
Flat Bones
Bones made up of a layer of spongy bone between two thin layers of compact bone. They have a flat shape, not rounded. Examples include the skull and rib bones. Flat bones have marrow, but they do not have a bone marrow cavity.
Sesamoid Bones
A small independent bone or bony nodule developed in a tendon where it passes over an angular structure, typically in the hands and feet. The kneecap is a particularly large sesamoid bone.
Sutural Bones
Accessory bones which occur within the skull. They get a different name, derivative from the suture or sutures they are in contact with or with the center of ossification or fontanel where they originate.
Irregular Bones
Bones which vary in shape and structure and therefore do not fit into any other category (flat, short, long, or sesamoid). They often have a fairly complex shape, which helps protect internal organs. For example, the vertebrae, irregular bones of the vertebral column, protect the spinal cord.
Ossification
The process in which cartilage is changed into bone.
Primary Ossification Center
The first area of a bone to start ossifying. It usually appears during prenatal development in the central part of each developing bone. In long bones the primary centers occur in the diaphysis/shaft and in irregular bones the primary centers occur usually in the body of the bone.
Bone Remodeling
The continuous, lifelong process in which existing bone is resorbed by osteoclasts and new bone is made by osteoblasts.
Bone Repair
The process in which bone heals itself following a bone fracture.
Joints
Locations at which bones of the skeleton connect with one another, also called an articulation.
Fibrous Joints
An immovable joint in which bones are connected by collagen fibers; also called a suture.
Cartilaginous Joints
A partly movable joint in which bones are joined by cartilage.
Synovial Joints
A movable joint in which a fluid-filled synovial cavity separates bones at the joint.
Immovable Joints
An articulation between bones in which no movement occurs. It is also referred to as synarthrotic (meaning immovable).
Partly Movable Joints
An articulation between bones (also called an amphiarthrotic joint) in which the motion is limited due to either fibrous tissue or cartilage.
Movable Joints
A joint in which the opposing bony surfaces are covered with a layer of hyaline cartilage or fibrocartilage and in which some degree of free movement is possible.
Ball-and-Socket Joint
A natural or manufactured joint or coupling, such as the hip joint, in which a partially spherical end lies in a socket, allowing multi-directional movement and rotation.
Pivot Joint
The joints that allow bones to rotate. In a pivot joint, a cylinder shaped bone rotates inside another bone or ligament that forms a ring around it.
Hinge Joint
A synovial bone joint in which the articular surfaces are molded to each other in such a manner as to permit motion only in one plane.
Saddle Joint
A type of synovial joint that allow articulation by reciprocal reception. Both bones have concave-convex articular surfaces which interlock like two saddles opposed to one another (example, the base of the thumb).
Plane Joint
A type of structure in the body, also called gliding joint, formed between two bones in which the articular, or free, surfaces of the bones are flat or nearly flat, enabling the bones to slide over each other.
Condyloid Joint
A synovial joint in which an oval-shaped process of one bone fits into a roughly elliptical cavity of the other, allowing movement in two planes.
Osteoporosis
A medical condition in which the bones become brittle and fragile from loss of tissue, typically as a result of hormonal changes, or deficiency of calcium or vitamin D.
Osteoarthritis (OA)
The degeneration of joint cartilage and the underlying bone, most common from middle age onward. It causes pain and stiffness, especially in the hip, knee, and thumb joints.
MUSCULAR SYSTEM
Muscular System
The body system responsible for the movement of the human body. Attached to the bones of the skeletal system are about 700 named muscles that make up roughly half of a person's body weight. Each of these muscles is a discrete organ constructed of skeletal muscle tissue, blood vessels, tendons, and nerves.
Muscle Fibers
A long, thin muscle cell that has the ability to contract.
Myocytes
A type of muscle cell that makes up smooth muscle tissue.
Hypertrophy
An increase in the size of a structure, such as an increase in the size of a muscle through exercise.
Atrophy
The decrease in the size of a structure, such as a decrease in the size of a muscle through non-use.
Sarcopenia
A gradual decrease in the ability to maintain skeletal muscle mass that occurs in later adulthood.
Neuromuscular Junction
A chemical synapse where a motor neuron transmits a signal to a muscle fiber to initiate a muscle contraction.
Musculoskeletal System
A body system which provides form, support, stability, and movement to the body. It is made up of the bones of the skeleton, muscles, cartilage, tendons, ligaments, joints, and other connective tissue that supports and binds tissues and organs together.
Tendons
Dense fibrous connective tissue that attaches skeletal muscle to bones.
Muscle Tissue
A soft tissue that composes muscles in animal bodies, and gives rise to muscles' ability to contract. This is opposed to other components or tissues in muscle such as tendons or perimysium.
Skeletal Muscle
Voluntary, striated muscle that is attached to bones of the skeleton and helps the body move.
Endomysium
Meaning within the muscle, is a wispy layer of areolar connective tissue that envelopes each individual muscle fiber. It also contains capillaries, nerves, and lymphatics. It overlies the muscle fiber's cell membrane.
Muscle Fascicles
A bundle of skeletal muscle fibers surrounded by perimysium, a type of connective tissue.
Perimysium
The sheath of connective tissue surrounding a bundle of muscle fibers.
Epimysium
A sheath of fibrous elastic tissue surrounding a muscle.
Sarcomeres
The basic functional unit of skeletal and cardiac muscles, containing actin and myosin protein filaments that slide over one another to produce a shortening of the sarcomere resulting in a muscle contraction.
Slow-Twitch Muscle Fibers
A type of skeletal muscle cell that is mainly responsible for aerobic activities such as long-distance running.
Fast-Twitch Muscle Fibers
A type of skeletal muscle cell that is mainly responsible for anaerobic activities such as weight lifting.
Smooth Muscle
An involuntary, nonstriated muscle that is found in the walls of internal organs such as the stomach.
Myocytes
A type of muscle cell that makes up smooth muscle tissue.
Cardiac Muscle
Involuntary, striated muscle found only in the walls of the heart; also called myocardium.
Muscle Contraction
Increase in the tension or decrease in the length of a muscle that occurs when muscle fibers receive stimulation from the nervous system.
Isometric
Referring to a muscle contraction in which muscle tension increases but muscle length remains the same.
Isotonic
Referring to a muscle contraction in which muscle length decreases but muscle tension remains the same.
Neuromuscular Junction
A chemical synapse where a motor neuron transmits a signal to a muscle fiber to initiate a muscle contraction.
Sliding Filament Theory
A theory that explains muscle contraction by the sliding of myosin filaments over actin filaments within muscle fibers.
Crossbridge Cycling
A sequence of molecular events that forms crossbridges between myosin and actin filaments in muscle fibers, allowing for muscle contraction. "Heads" on the myosin filaments essentially form a connection with specific locations on the actin, and then the head bends in order to pull the myosin strand along the actin to shorten the sarcomere.
Musculoskeletal Disorders
An injury to muscles or tendons caused by biomechanical stresses.
Muscle Strain
An injury in which muscle fibers tear due to overstretching of a muscle.
Tendinitis
Inflammation of a tendon when it is over-extended or worked too hard without rest.
Carpal Tunnel Syndrome
A musculoskeletal disorder that occurs when a nerve becomes compressed between carpal bones in the wrist, leading to reduced innervation of the thumb and first two fingers.
Neuromuscular Disorder
A disorder that occurs due to problems with the nervous control of muscle contractions or with muscle cells themselves.
Muscular Dystrophy
A genetic neuromuscular disorder caused by defective proteins in muscle cells and characterized by death of skeletal muscles and progressive weakness.
Myasthenia Gravis
A genetic neuromuscular disorder caused by the immune system blocking or destroying acetylcholine receptors on muscle cells and characterized by progressive muscle weakness and fatigue.
Parkinson's Disease
A degenerative brain disorder caused by progressive death of neurons in the midbrain, resulting in muscular symptoms of tremor, rigidity, slowness of movement, and postural instability.