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
Fibrous Connective Tissue
- dense with collagenous fibres
- found in tendons (attach muscles to bones, & ligaments, which connect bones at joints)
Bone
connective tissue
- skeleton of most vertebrates
- living tissue that secretes a really hard matrix that holds the cells in place, but bone itself is a living organ
Cartilage
at the end of a bone, skeletal elements in our noses and ears, and joints where they cushion one bone to another
- contains collagenous fibres embedded in a rubbery protein-carbohydrate complex
- strong yet flexible support material
- skeletons of vertebrate embryo contain cartilage that is replaced by bone
Adipose
specialized loose CT; stores fat in adipose cells distributed throughout its matrix
- each cell contain little droplets of fats/lipids
- pads & insulates the body & stores fuel as fat molecules
Blood
connective tissue
- has a liquid extracellular matrix called plasma, which consists of water, salts, & dissolved proteins
- in plasma, red cells carry oxygen, white cells function in defence, & platelets aid in blood clotting
Extracellular matrix
the meshwork surrounding animal cells
Differentiate between the 4 general adult tissues types.
epithelial: sheets of closely packed cells; cover body and organs
connective: typically, sparely distributed cells in a secreted matrix
muscle: responsible for nearly all types of body movement
nervous: functions in the receipt, processing, & transmission of information
What is anatomy?
shape of things/organisms
What is physiology?
how things work, how parts of the body work together and how the different cells metabolism, and how things just do what they do
What did Lamack believe?
“form follows function”
- ex: giraffes have to stretch their necks to reach, will cause their necks to grow
- the more you use something, the stronger its going to be
What did Darwin believe?
“form precedes function”
- whether you can use a function
- ex: if you have a long neck you are more likely to survive and offspring will win over those who don’t have a longer neck
How can Cogenital Mirror Movement Disorder come to be?
ex: right side of brain controls left side of body and vice versa (all nerves)
- can make mistakes (b/c sometimes they don’t jump to the other side)
What is tissue?
integrated group of similar cells that perform a common function
Which Epithelial Tissues are collagen present in?
- simple squamous epithelium
- cuboidal epithelium
- pseudostratified columnar epithelium
- stratified squamous epithelium
What is categorized as a Negative feedback loop?
- body temp
- blood pH
- blood sugar levels
- blood calcium levels
- thyroid hormone levels
- bile production
- and so many others
What is categorized as a Positive feedback loop?
- amplify changes rather than dampsen them (bigger & bigger until system breaks)
- a few ex’s:
- blood clotting
- uterine contractions (mediated by oxytocin)
- male ejaculation (also mediated by oxytocin)
Muscle tissue
tissue responsible for nearly all types of body movement 3 types: 1. skeletal muscle 2. smooth muscle 3. cardiac muscle
What happens when temp falls BELOW set point?
the hypothalamus activates WARMING mechanisms
- blood vessels in the skin CONSTRICT (narrow), MINIMIZING heat loss
- skeletal muscles CONSTRUCT; SHIVERING generates heat
- temp increases (the hypothalamus shuts off the warming mechanisms)
What happens when temp RISES above set point?
the hypothalamus activates cooling mechanisms
- blood vessels in the skin DILATE (expand); INCREASING heat loss
- glands secrete SWEAT that evaporates cooling the body
- temp decreases (the hypothalamus shuts off the cooling mechanisms)
