chapter 38 ~ tissues, systems, feedback systems Flashcards
A group of cells with a similar structure and specialized function
Tissue
Integrates two or more different tissues into a structure that performs a particular function
Organ
Collection of organs with a related function
Organ system
Attain cells to each other
found in skin, heart, muscle
Anchoring junctions
Adjacent cells fuse
bladder
Tight junctions
Direct channels
Allows tissues, ions, molecules to flow rapidly
Gap junctions
Structure: sheetlike layers of cells (5 types)
Function: PSA protection secretion absorption
Location: surfaces of internal organs, line cavities and ducts
Exocrine- duct Endocrine- ductless, releases hormones
Epithelial tissue
Layer of flattened cells
Locations: blood vessel inner lining (called endothelium); air sacs of lungs
Function: diffusion
Simple squamous epithelium
Several layers of flattened cells
Locations: skin and other surfaces subject to abrasion, such as mouth, esophagus, and vagina
Function: protection against abrasion; typically not involved in secretion or absorption
Stratified squamous epithelium
Layer of cubelike cells; free surface may have microvilli
Locations: glands and tubular parts of nephrons in kidneys
Function: secretion, absorption
Cuboidal epithelium
Layer of tall, slender cells with nuclei near base; free surface may have microvilli or cilia; may contain secretory vesicles
Locations: lining of gut, services canal, and gallbladder
Function: secretion, absorptions, such as secreting digestive enzymes and absorbing nutrients in the gut, protection; secreting mucus
Simple columnar epithelium
Single layer of columnar cells of differing heights; some cells do not reach the apical surface due to the cell organization, the nuclei are staggered, giving the epithelium the false appearance of stratification. May be ciliated
Locations: nasal cavities, trachea, and upper digestive tract; some parts of male reproductive system
Function: protection, secretes mucus and moves it across surface
Simple pseudostratified columnar epithelium
Function: structural support
Connective tissue
Six types of connective tissues
Loose connective
Dense connective
Cartilage
Bone
Adipose
Fibroblasts make….
Collagen - strong and tensile - tendons and ligaments
Reticular fibers- thin collagen fibers forming network
Elastic fibers- rubbery protein, adds stretch
Structure: fibroblasts open network with collagen, contain elastin forming glycoprotein matrix
Function: structural support
Locations: under the skin, organs, blood vessel, covering, nerves
Loose connective tissue
Structure: fibroblasts with dense network collagen
Function: structural support- resist stretch and provide strength
Location: digestive tract, tendons and ligaments
Dense connective tissue
Structure: chondrocytes surround networks of collagen
Function: support and flexibility
Location: end of long bones, ears, nose
Cartilage tissue
Structure: osteoclasts and osteoblasts
Function: structural support- build or break for support
Location: in the bone
Osteoblast- secrete collagen and minerals into bone
Osteoclast- remove minerals and recycle into bloodstream
Bone tissue
Structure: adipocytes
Function: fat storage cells
Location: under skin, around heart
Adipose tissue
Structure: cardiac, skeletal, smooth
Function: transport and contraction
Location: circulatory system
Blood tissue
Structure: actin and myosin proteins arranged in patterns dependent on their function
Function: produce movement in the body
3 types: skeletal, cardiac, and smooth
Muscle tissue
Structure: multi nucleated and striated. Unidirectional parallel bundles
Function: voluntary movement, generations of heat, maintaining posture and joint location
Location: large muscles connected to bones by tendons
Skeletal muscle tissue
Structure: striated and branched. Contain intercalated discs with gap junctions
Function: provide constant, synchronized contractions of heart muscle for blood flow
Location: the heart
Cardiac muscle tissue
Structure: loose network of spindle shaped cells
Function: provide involuntary movements of internal organs
Location: walls of blood vessels, digestive organs, hair follicles
Smooth muscle tissue
Structure: Consists of polarized neurons and glial cells
Function: communication and control of body parts
Location: practically everywhere
Nervous tissue
Dendrites: receive axonal signals
Axons: transmit signals to other neurons
Cell body: contains nucleus and other organelles
Neurons
Regulation of the internal environment to maintain a relatively stable state
Maintain by organ systems that coordinate together
Homeostasis
Match their internal environment to the exterior
Conformers
Maintain a constant internal environment regardless of exterior
Conformers
Maintain a constant internal environment regardless of exterior
Regulators
Operate only within the target organ
Example is dilation of blood vessels in active muscle
Local controls
Are initiated outside of the target organ
Example is the endocrine system
Systemic controls
Most common homeostatic control function, acts to reduce change
Stimulus, sensor, integrator, effector, compensatory response, environmental condition returned to set point
Negative feedback
A change results in signals that intensify change in same direction
Ex: in childbirth, contractions trigger stretch sensors that sent signals to hypothalamus to release oxytocin to further increase contractions
Do not result in homeostasis, it is not as common as negative feedback
Positive feedback
When a set point changes naturally because of an alteration in environmental conditions
Acclimatization
When a set point changes artificially in a laboratory setting
acclimation
