animal form & function Flashcards
Regulation
an animal is said to be a regulator for a particular environmental variable if it uses internal mechanisms to control internal change in the face of external fluctuation
- the otter is a regulator for temperature, keeping its body at a temperature that is largely independent of the water in which it swims
Conformation
an animal is a conformer for a particular variable if it allows its internal condition to change in accordance with external changes in the variable
- the bass conforms to the temperature of the lake it inhabits
- as the water warms or cools, so does the body of the bass
Homeostasis
means “same state”
- referring to the maintenance of internal balance
- in achieving homostasis, animals maintain a relatively constant internal environment even when the external environment changes significantly
Epithelium
occuring as sheets of closely packed cells, cover the outside of the body and line organs and cavities within the body
- b/c epithelial cells are closely packed, often with tight junctions, they function as a barrier against mechanical injury, pathogens, and fluid loss
Simple Squamous Epithelium
thin & leaky
single layer of platelike cells
- allow materials to pass through by diffusion & filtration, & secretes lubricating substance
- lines air sacs of lungs & the lining of the heart, blood vessels, & lymphathic vessels
Cuboidal Epithelium
- thicker
- secretes & absorbes; some are ciliated
- makes up the epithelium of kidney tubules & many glands, including the thyroid gland & salivary glands
Simple Columnar Epithelium
thicker (large brick-shaped cells)
- absorbs; it also secretes mucous & enzymes
- CILLIATED tissues are in bronchi uterine tubes, & uterus
- SMOOTH (nonciliated tissues) are in the digestive tract, bladder
- lines the intestines, secreting digestive juices & absorbing nutrients
Pseudostratified Columnar Epithelium
thicker (single layer of cells varying in height)
- secretes mucous; ciliated tissue moves mucus
- ciliated tissue lines the trachea & much of the upper respiratory tract
Stratified Squamous Epithelium
for protective surfaces; impermeable to most materials; protects against abrasion
- multilayered & regenerates rapidly
- commonly found on surfaces subject to abrasion, such as the outer skin and the linings of the mouth, esophagus anus and vagina
Skeletal muscle
attached to bones by tendons
- striated
- consists of bundles of long cells called muscle fibres
- responsible for the voluntary movements
Cardiac muscle
forms the contractile wall of the heart
- striated
- has fibres that interconnect via intercalated disks, which relay signals from cell to cell & help synchronize heart contraction
Smooth muscle
- lacks striations
- found in the walls of the digestive tract, urinary bladder, arteries, and other internal organs
- responsible for involuntary body activities (such as churning of the stomach & constriction of arteries)
Nervous tissue
functions in the receipt, processing, and transmission of information
- contains neurons, or nerve cells, which transmit nerve cells, which transmit nerve impulses, as well as support cells called glial cells, or simply glia
- in many animals, a concentration of nervous tissue forms a brain, an information-processing centre
Connective tissue
consisting of a sparse population of cells scattered through an extracellular matrix, holds many tissues & organs together in place
- Loose connective tissue
- Fibrous connective tissue
- Adipose tissue
- Cartilage
- Bone
- Blood
Loose Connective Tissue
- most widespread CT in vertebrates
- has loose weave of its fibres, has all 3 types
- found in the skin & throughout the body
