Ch. 4 Flashcards
Tissue
A collection of cells of the same type that perform a common function
What are the four major tissue types?
Connective, Muscular, Nervous, and Epithelial
What are the three main types of connective tissue?
Fibrous, supportive, and fluid
What are the three main components of all connective tissue types?
Specialized cells, ground substances, and protein fibers
Ground substance
Noncellular material between the cells; varies in consistency from solid (bone) to fluid (blood)
What are the three types of protein fibers?
Collagen, reticular, and elastic fibers
Collagen fibers
Flexible and strong
Reticular fibers
Thing, highly branched collagen fibers
Elastic fibers
Contain elastin. a protein that stretches and recoils
What are the two main forms of fibrous connective tissue?
Loose and dense
Loose fibrous connective tissue is made up of:
Includes areolar, reticular, and adipose tissue
Dense fibrous tissue present in:
Tendons and ligaments
Loose fibrous connective tissue
Supports epithelium and many internal organs; its functions include energy storage, insulation, and cushioning
Dense fibrous connective tissue contains:
Densely packed collagen fibers
What are the two major types of supportive connective tissue
Cartilage and bone
What are the functions of the two supportive connective tissue?
Structure, shape, protection, and leverage for movement
Cartilage
Chondrocytes, matrix is solid but flexible, lacks a direct blood supply (heals slowly)
Chondrocytes
Cells that lie in small places called lacunae
What are the three types of cartilage and how are they distinguished?
Distinguished by the type of fibers found in the matrix:
Hyaline, Elastic, and Fibrocartilage
Hyaline cartilage is
Fine collagen fibers and found in the tip of the nose, ends of long bones, and the fetal skeleton
Elastic cartilage is
Lots of elastic fibers and is found in the outer ear
Fibrocartilage is
Strong collagen fibers and is found in the disks between vertebrae
Bone
The most rigid connective tissue, matrix is made of collagen and calcium salts
What are the two bone types?
Compact and spongy bones
Compact bone
Contain osteons which are cylindrical structural units, makes up the shafts of long bones
Spongy bone
Is inside the ends of long bones, lighter than compact bone, but strong
What are the two types of fluid connective tissue?
Blood and lymph
Blood
Consists of a fluid matrix called plasma and cellular components, or formed elements
What are the three formed elements?
Red blood cells, white blood cells, and platelets
Red blood cells
Cells that carry oxygen (erythrocytes)
White blood cells
Cells that fight infections (leukocytes)
Platelets
Pieces of cells that clot blood (thrombocytes)
Lymph
Derived from the fluid surrounding tissues, contains white blood cells
Lymphatic vessels
Absorb excess interstitial fluid and return lymph to the cardiovascular system
Muscular tissue
Specialized to contract, cells are called muscle fibers
What are the three types of muscle tissue?
Skeletal, smooth, and cardiac
Skeletal muscle
Attached to the skeleton by tendons, contractions move the skeleton, voluntarily controlled
Skeletal muscle components (fiber)
Very long, can run the entire length of the muscle, have multiple nuclei, striated (striped)
Smooth muscle
No striations, spindle-shaped cells with one nucleus, involuntarily controlled, found in the walls of viscera
Cardiac Muscle
Found only in the walls of the heart, striated, involuntary, single nucleas, cells are connected by intercalated disks
Nervous tissue consist of what?
Neurons and Neuroglia
What are the three primary functions of the nervous tissue?
Sensory input, integration, and motor output
Of what three parts do neurons consist of?
Dendrites, a cell body, and an axon
Dendrites
Carry information toward the cell body
Cell body
Contains the nucleus and other organelles
Axon
Conducts nerve impulses away from the cell body
Myelin
A fatty substance that covers some axons, increases the rate of signal transduction
Nerves
Bundles of axons traveling to and from the brain and spinal cord
Neuroglia
Outnumer neurons 9 to 1, take up more than half of the volume of the brain, main function is to support and nourish neurons (astrocytes, microglia)
Epithelial tissue
Consists of tightly packed cells, lines body cavities, body surfaces, and is found in glands, anchored by a basement membrane on one side and is free on the other
Simple epithelium
Single layer of cells
Stratified epithelium
Multiple layers of cells
Simple squamous epithelium
Single layer of flattened cells, found in the lungs where it functions in gas exchange
Simple cuboidal epithelium
Single layer of cube-shaped cells
Simple columnar epithelium
Single layer of column-shaped cells
Pseudostratified columnar epithelium
Because of the location of the nuclei, appears stratified but every cell touches the basement membrane, often has cilia, which move mucus across its surface
Glands
One or more cells that make and secrete a products
What are the two types of glands?
Exocrine and Endocrine
Exocrine glands
Secrete into ducts
Endocrine glands
Secrete into the bloodstream, have no ducts
Stratified squamous epithelium
Consists of several layers of flattened cells, forms the outer layer of the skin, and lines the mouth and esophagus
Transitional epithelium
Cells change shape in response to tension (from cuboidal to squamous) Lining of the urinary bladder
What does the integumentary system include?
Skin, accessory organs such as hair, nails, and glands
What are the functions of the integumentary system?
Protects underlying tissues from trauma, pathogen invasion, and water loss, helps regulate body temperature, contains sensory receptors, such as touch and temperature receptors, and makes us aware of our surroundings
What are the 2 main regions of the skin
The epidermis and the dermis, beneath the dermis there is a subcutaneous layer (hypodermis)
Epidermis
Thin, outermost layer of the skin, made of stratified squamous epithelium, new epidermal cells are in the deepest layer (produced by stem cells)
Autograft
From another area of the body
Allograft
From another person
Keratinocytes
In the upper layer of epidermis, dead and filled with keratin, forms a waterproof barrier
Langerhans cells
A type of white blood cell
Melanocytes
Produce melanin, which produces skin color and protects from UV lights
What are some other contributors to skin color?
Carotene and hemoglobin
Skin Cancer
Caused by UV rays from the sun
Basal cell carcinoma
Cancer of epidermal stem cells, most common type of skin cancer; curable
Melanoma
Cancer of melanocytes, extremely serious, can be malignant
The dermis
Thick, inner layer of the skin
What is the dermis made up of and what does it contain?
Made of dense fibrous connective tissue, contains collagen and elastin for strength and elasticity. Also contains blood vessels, sensory receptors, and glands.
Subcutaneous layer
Also called hypodermis, technically not part of the skin and is composed of loose connective tissue and adipose tissue. It stores energy, insulates, and protects.
Nails
Offer a protective covering of the digits (fingers and toes) Grow from the nail root to cover the nail bed.
Digits
Fingers and toes
Cuticle
Covers the nail root
Lunula
White half-moon shape at the base
Hair follicles
Epidermal structures that surround the hair itself
Hair shaft
The portion of hair protruding from the skin
Arrector pili muslces
Attached to the hair follicle
Sebaceous glands
Oil glands, produce sebum, retards bacterial growth, acne which is caused by inflammation
Sudoriferous glands
Sweat glands, in the dermis, their ducts open onto the skin surface to help regulate body temperature
What are the two main body cavities
Ventral and Dorsal
Ventral cavity
(Belly) contains the thoracic, abdominal, and pelvic cavities. The thoracic and abdominal cavities are separated by the diaphragm
Dorsal Cavity
(Back) Contains the cranial cavity and vertebral canal
Body membranes
Line cavities and the internal spaces of organs and tubes that open to the outside
What are the four types of body membranes?
Mucous, serous, synovial membranes and the meninges
Mucous membranes
Secrete mucus, lines the tube of the digestive, respiratory, urinary, and reproductive systems
What are mucous membranes composed of (and what do they contain)
Composed of epithelium overlying loose fibrous connective tissue, contains goblet cells that secrete mucus.
Serous membranes
Line closed cavities, and cover the surface of the organs contained within
Pleural membranes
Line the thoracic cavity and cover the lungs
Pericardium
Forms the pericardial sac and covers the heart
Peritoneum
Lines the abdominal cavity (peritoneal cavity) and covers its organs
Synovial membranes
Composed only of loose connective tissue, line freely moveable joints (ex. the knees) secrete synovial fluid for lubrication
Meninges
Composed only of connective tissue, in the dorsal cavity, and when inflamed causes meningitis
What are the two parts of the internal environment?
Blood and interstitial fluid
Interstitial fluid
Surrounds the outside of cells; substances are exchanged through it
What are the two mechanisms for maintaining homeostasis?
Negative and positive feedback
Negative feedback
The primary mechanism used in the body, has two components, the output of the system turns down, or off the production
What are the two components in negative feedback?
A sensor and a control center
Positive feedback
Brings about a change in the same direction as the original stimulus, can be harmful in some situations
