Chapter 3: The cells, tissues and organization of the body Flashcards
What are cells?
the body’s smallest functional units
Cells are group together to form?
tissues-each of which has a specialized function, e.g., blood, muscle, bone.
Tissues are grouped together to form?
organs, e.g., the heart, stomach, and brain.
organs are grouped together to form?
systems, each of which performs a particular function that maintains homeostasis and contributes to the health of the individual
what are the two types of cells?
Prokaryotes
Eukaryotes
Characteristic of a cell?
Cells provide structure and support to the body of an organism.
The nucleus
(major organelle) holds genetic information necessary for reproduction and cell growth.
Mitochondria
a double membrane-bound organelle is mainly responsible for the energy transactions vital for the survival of the cell.
Lysosomes
digest unwanted materials in the cell.
Endoplasmic reticulum
plays a significant role in the internal organization of the cell by synthesizing selective molecules and processing, directing, and sorting them to their appropriate locations.
plasma membrane
The plasma membrane of a cell is a network of lipids and proteins that forms the boundary between a cell’s contents and the outside of the cell.
The main function of the plasma membrane is to protect the cell from its surrounding environment.
membrane proteins
are the binding proteins that mediate conduction of ions or molecules into and out of the cell membrane.
Chromosome
is a string of DNA wrapped around associated proteins that give the connected nucleic acid bases a structure.
ribosomes
are the sites at which information carried in the genetic code is converted into protein molecules.
Goli apparatus
is an organelle in eukaryotic organisms that moves molecules from the endoplasmic reticulum to their destination.
Lysosomes
are small membranous vesicles pinched off from the Golgi apparatus.
Cytoskeleton
a microscopic network of protein filaments and tubules in the cytoplasm of many living cells, giving them shape and coherence.
microfilaments
These are the smallest fibers. They provide structural support, maintain the characteristic shape of the cell and permit contraction, e.g., actin in muscle cells.
microtubules
These are larger contractile protein fibers that are involved in the movement of:
- organelles within the cell
- chromosomes during cell division
- cell extensions
Interphase
the resting phase between successive mitotic divisions of a cell, or between the first and second divisions of meiosis
mitosis
a type of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent nucleus, typical of ordinary tissue growth.
Prophase
the first stage of cell division, before metaphase, during which the chromosomes become visible as paired chromatids and the nuclear envelope disappears. The first prophase of meiosis includes the reduction division.
metaphase
the second stage of cell division, between prophase and anaphase, during which the chromosomes become attached to the spindle fibers.
anaphase
the stage of meiotic or mitotic cell division in which the chromosomes move away from one another to opposite poles of the spindle.
telophase
the final phase of cell division, between anaphase and interphase, in which the chromatids or chromosomes move to opposite ends of the cell and two nuclei are formed.
passive transport
the movement of substances (as by diffusion) across a cell membrane without the expenditure of energy.
diffusion
is the net passive movement of molecules or particles from regions of higher to regions of lower concentration.
Osmosis
is the passive movement of water down its concentration gradient towards equilibrium across a semipermeable membrane.
Active transport
This is the transport of substances up their concentration gradient (uphill), i.e., from a lower to a higher concentration
Sodium-Potassium Pump
the process of moving sodium and potassium ions across the cell membrane is an active transport process involving the hydrolysis of ATP to provide the necessary energy.
Bulk Transport
Transfer of particles too large to cross cell membranes occurs by pinocytosis (‘cell drinking) or phagocytosis (‘cell eating).
Tissues
Tissues consist of large numbers of the same type of cells and are classified according to the size, shape, and functions of their constituent cells.
Epithelial Tissue
Forms the outer covering of the skin and lines the body cavity.
The structure of epithelium is closely related to its functions, which include:
-protection of underlying structures from, for example, dehydration, chemical, and mechanical damage
-secretion
-absorption
Simple epithelium
has only one cell layer where every cell is in direct contact with the underlying basement membrane.
Squamous epithelium
This is composed of a single layer of flattened cells. The cells fit closely together like flat stones, forming a thin and very smooth membrane across which diffusion occurs easily.
cuboidal epithelium
Simple cuboidal epithelium is a type of epithelium that consists of a single layer of cuboidal (cube-like) cells. These cuboidal cells have large, spherical, and central nuclei. … On these surfaces, the cells perform secretion and absorption.
Columnar epithelium
Columnar epithelial cells are elongated and column-shaped and have a height of at least four times their width. Their nuclei are elongated and are usually located near the base of the cells. Columnar epithelium forms the lining of the stomach and intestines.
Stratified epithelia
is the lining of cells that covers most body surfaces and cavities, with an attached membrane called a basement membrane.
Stratified squamous epithelium
is a tissue formed from multiple layers of cells resting on a basement membrane, with the superficial layer(s) consisting of squamous cells.
Keratinized stratified epithelium
refers to an outer layer of skin cells that have become hardened and died.
This layer protects the tissues that lie underneath, and it prevents certain substances from passing into or out of the tissues below.
Non-Keratinized stratified epithelium
is the epithelium in which the cells do not have a lot of keratin deposits within them, but rather are moisturized by mucus from the salivary or the mucus glands.
Transitional epithelium
is a stratified tissue made of multiple cell layers, where the cells constituting the tissue can change shape depending on the distention in the organ.
connective tissue
the most abundant tissue in the body.
• Connective tissue, group of tissues in the body that maintain the form of the body and its organs and provide cohesion and internal support.
Fibroblasts
A cell in connective tissue which produces collagen and other fibers
Fat cells
Also known as adipocytes, these cells occur singly or in groups in many types of connective tissue and are especially abundant in adipose tissue.
Macrophages
a large phagocytic cell found in stationary form in the tissues or as a mobile white blood cell, especially at sites of infection
Leukocytes
a colorless cell that circulates in the blood and body fluids and is involved in counteracting foreign substances and disease; a white (blood) cell.
Mast cells
Is a resident cell of connective tissue that contains many granules rich in histamine and heparin.
Mast cells mediate inflammatory responses such as hypersensitivity and allergic reactions.
Loose (Areolar) connective tissue
This is the most generalized type of connective tissue.
It is found in almost every part of the body, providing elasticity and tensile strength. It connects and supports other tissues, for example:
-under the skin
-between muscles
-supporting blood vessels and nerves
Adipose tissue
Adipose tissue consists of fat cells (adipocytes), containing large fat globules, in a matrix of areolar tissue. There are two types: white and brown.
White adipose tissue
White adipose tissue is the most common type of adipose tissue in the body. 20% of the total weight of a man is White adipose tissue.
Refers to a type of loose connective tissue composed of white, lipid-filled cells
Brown adipose tissue
Is a special type of body fat that is turned on (activated) when you get cold. Brown fat produces heat to help maintain your body temperature in cold conditions.
Reticular tissue
The reticular connective tissues are found in the kidney, the spleen, lymph nodes, and bone marrow. Their function is to form a stroma and provide structural support, such as that in the lymphoid organs, e.g. red bone marrow, spleen, and lymph node stromal cells.
Dense connective tissue
This contains more fibers and fewer cells than loose connective tissue.
Fibrous tissue
A simple, strong structural or repair tissue consisting of twisted strands of collagen and laid down by cells known as fibroblasts.
Fibrous tissue is found:
- forming ligaments, which bind bones together
- as an outer protective covering for bone, called periosteum
- as an outer protective covering of some organs, e.g., the kidneys, lymph nodes and the brain
- forming muscle sheaths, called muscle fascia, which extend beyond the muscle to become the tendon that attaches the muscle to bone.
Elastic tissue
A type of connective tissue consisting mainly of elastic fibers and found in the walls of arteries, dermis of the skin, and certain ligaments and tendons.
Cartilage
firm, whitish, flexible connective tissue found in various forms in the larynx and respiratory tract, in structures such as the external ear, and in the articulating surfaces of joints. It is more widespread in the infant skeleton, being replaced by bone during growth.
Chondrocytes
a cell which has secreted the matrix of cartilage and become embedded in it. There are three types: hyaline cartilage, fibrocartilage and elastic fibrocartilage.
Hyaline cartilage
Hyaline cartilage provides flexibility, support and smooth surfaces for movement at joints. It is found:
- on the ends of long bones that form joints
- forming the costal cartilages, which attach the ribs to the sternum
- forming part of the larynx, trachea and bronchi
Fibrocartilage
This consists of dense masses of white collagen fibers in a matrix like that of hyaline cartilage with the cells widely dispersed. It is a tough, slightly flexible, supporting tissue found:
- as pads between the bodies of the vertebrae, the intervertebral discs
- between the articulating surfaces of the bones of the knee joint, called semilunar cartilages
- on the rim of the bony sockets of the hip and shoulder joints, deepening the cavities without restricting movement.
Elastic fibrocartilage
A tough, elastic, fibrous connective tissue that is a major constituent of the embryonic and young vertebrate skeleton and in most species is converted largely to bone with maturation. It is found in various parts of the human body, such as the joints, outer ear, and larynx.
Bone
Bone cells (osteocytes) are surrounded by a matrix of collagen fibers strengthened by inorganic salts, especially calcium and phosphate. This provides bones with their characteristic strength and rigidity. Two types of bone can be identified by the naked eye:
- compact bone – solid or dense appearance
- spongy or cancellous bone – ‘spongy’ or fine honeycomb appearance.
Muscle tissue
This tissue can contract and relax, providing movement within the body and of the body itself.
Muscle contraction requires a blood supply that will provide sufficient oxygen, calcium and nutrients and remove waste products.
There are three types of specialized contractile cells, also known as fibers: skeletal muscle, smooth muscle and cardiac muscle.
Skeletal muscle
Each skeletal muscle consists of thousands of muscle fibers wrapped together by connective tissue sheaths. The individual bundles of muscle fibers in a skeletal muscle are known as fasciculi.
Skeletal muscle contraction is stimulated by motor nerve impulses originating in the brain or spinal cord and ending at the neuromuscular junction.
Smooth muscle
Smooth muscle, also called involuntary muscle, muscle that shows no cross stripes under microscopic magnification. It consists of narrow spindle-shaped cells with a single, centrally located nucleus. Smooth muscle tissue, unlike striated muscle, contracts slowly and automatically.
Cardiac muscle
Cardiac muscle tissue, or myocardium, is a specialized type of muscle tissue that forms the heart. This muscle tissue, which contracts and releases involuntarily, is responsible for keeping the heart pumping blood around the body.
Nervous tissue
Two types of tissue are found in the nervous system:
- excitable cells – these are called neurons and they initiate, receive, conduct and transmit information
- non-excitable cells – also known as glial cells, these support the neurons.
Tissue regeneration
Tissue regeneration is a resource-intensive process which depends on the ability of stem cells to recognize when to enter and exit a readily reversible state of proliferative inactivity.
Membranes (Epithelial membranes)
Epithelial membranes are formed from epithelial tissue attached to a layer of connective tissue. There are three types of epithelial membranes: mucous, which contain glands; serous, which secrete fluid; and cutaneous which makes up the skin.
Mucous membrane
Membrane lining body cavities and canals that lead to the outside, chiefly the respiratory, digestive, and urogenital tracts.
Serous membrane
is a thin membrane that lines the internal body cavities and organs such as the heart, lungs, and abdominal cavity.
Synovial membrane
This membrane lines the cavities of moveable joints and surrounds tendons that could be injured by rubbing against bones, e.g., over the wrist joint.
Median plane
When the body is divided longitudinally through the midline into right and left halves it has been divided in the median plane.
Coronal plane
A coronal or frontal section divides the body longitudinally into its anterior (front) and posterior (back) sections.
Transverse plane
A transverse or horizontal section provides a cross section dividing the body or body part into upper and lower parts.
Paired terms used in anatomy
- Medial: Structure is nearer to the midline. The heart is medial to the humerus
- Lateral: Structure is further from the midline or at the side of the body.
- Proximal: Nearer to a point of attachment of a limb, or origin of a body part.
- Distal: Further from a point of attachment of a limb, or origin of a body part.
- Anterior or ventral: Part of the body being described is nearer the front of the body.
- Posterior or dorsal: Part of the body being described is nearer the back of the body.
- Superior: Structure nearer the head. The skull is superior to the scapulae
- Inferior: Structure further from the head. The scapulae are inferior to the skull
The skeleton
The skeleton is the bony framework of the body.
The skeleton is described in two parts: axial and appendicular
Axial skeleton
The axial skeleton (axis of the body) consists of the skull, vertebral column, sternum (breastbone) and the ribs.
Skull
The skull is described in two parts, the cranium, which contains the brain, and the face.
Vertebral column
The vertebral column, also known as the spinal column, is the central axis of the skeleton in all vertebrates. The vertebral column provides attachments to muscles, supports the trunk, protects the spinal cord and nerve roots, and serves as a site for hemopoiesis.
Thoracic cage
The thoracic cage (human rib cage) is a bony and cartilaginous structure which surrounds the thoracic cavity and supports the pectoral girdle, forming a core portion of the human skeleton.
Appendicular skeleton
• The appendicular skeleton consists of the shoulder girdles and upper limbs, and the pelvic girdle and lower limbs.
The shoulder girdle
The shoulder girdle or pectoral girdle is the set of bones in the appendicular skeleton which connects to the arm on each side. In humans it consists of the clavicle and scapula; in those species with three bones in the shoulder, it consists of the clavicle, scapula, and coracoid.
The pelvic girdle
Pelvis, also called bony pelvis or pelvic girdle, in human anatomy, basin-shaped complex of bones that connects the trunk and the legs, supports and balances the trunk, and contains and supports the intestines, the urinary bladder, and the internal sex organs.
cranial cavity
The cranial cavity, also known as intracranial space, is the space within the skull. The space inside the skull is formed by eight cranial bones known as the neurocranium. … The skull (minus the mandible) is also known as the cranium, and contains the brain.
Thoracic cavity
Thoracic cavity, also called chest cavity, the second largest hollow space of the body. It is enclosed by the ribs, the vertebral column, and the sternum, or breastbone, and is separated from the abdominal cavity (the body’s largest hollow space) by a muscular and membranous partition, the diaphragm.
Abdominal cavity
The abdominal cavity, largest hollow space of the body. … Vertically it is enclosed by the vertebral column and the abdominal and other muscles. The abdominal cavity contains the greater part of the digestive tract, the liver and pancreas, the spleen, the kidneys, and the adrenal glands located above the kidneys.
Pelvis cavity
The pelvic cavity is a body cavity that is bounded by the bones of the pelvis. Its oblique roof is the pelvic inlet (the superior opening of the pelvis). … The pelvic cavity primarily contains the reproductive organs, urinary bladder, distal ureters, proximal urethra, terminal sigmoid colon, rectum, and anal canal.
Apoptosis
The death of cells which occurs as a normal and controlled part of an organism’s growth or development
Necrosis
This is cell death resulting from lack of oxygen (ischemia), injury, or a pathological process.
Tumors
A swelling of a part of the body, generally without inflammation, caused by an abnormal growth of tissue, whether benign or malignant.