cells and tissues

all animal cells share similarities in the ways in which they:

exchange materials with their surroundings, obtain energy from organic nutrients, synthesize complex molecules, reproduce themselves and detect/respond to signals in their immediate environment

levels of organization

cellular- phylum proferia

tissue- cnidaria and ctenotophora

organ- phatyhelminthes

organ system- advanced animals groups

what are the four kinds of tissue

• epithelial

• connective

• muscle

• nervous

epithelial characteristics

• cover the body or enclose organs

• line the walls of body cavities and organs

• specialized to protect and secrete/ absorb ions and organic molecules

cell shapes

• cuboidal- cubed

• squamous- flattened cells

• columnar- elongated cells

tissue layers

• simple = 1

• stratified = more than one

• pseudostratified = one layer that appears stratified

all tissues are

asymetrical or polarized

• one side rests on basal lamina and the other faces the environment

• can function as selective barriers

what are the types of epithelial

• simple squamous

• simple cuboidal.

• simple columnar

• pseudostratified columnar

• transitional

ALL may be available for secretion/ absorption and some protection

connective tissue characteristics

connect, surround, anchor, bind transport and support

Froms the ECM

what is the purpose of the ECM

• provides scaffold for attachment

• provides protection and cushions

• mechanical strength

• transmit information

what are the types of connective tissue

• blood- transport and protection

• adipose- fat- insulation, energy, support and protection

• bone- support and protection

• cartilage- support and flexibility

• loose- holds internal organs in place

• dense- strength and support

muscle cells

specialized to contract, generating mechanical force

what are the kinds of muscle

• skeletal

• smooth

• caridac

skeletal muscle

• attached to bone or exoskeleton for locomotion; elongate fibers; voluntary control

smooth muscle

• surrounds tubes and cavities for propulsion of contents; flattened cells; involuntary control

cardiac muscle

• only in heart; elongate fibers; involunatry control

nervous tissue

a complex network of neurons/ nerve cells

these cells initiate and conduct electrical signals from one part of the animals body to another

electrical signals produced in one neuron may stimulate or inhibit other neurons to

• initiate new electrical signals

• stimulate muscle cells to contract

• stimulate grandular cells to release chemicals

neurological cells

• more numerous than neurons

• provide metabollic support, maintenance, ion balance and cleaning for the neurons

• produce new glial cells and neurons

what causes the body plan (spatial arrangment of organs into organ systems)

• hox genes

• highly conserved family genes w homologs in all animals

what influences homeostasis

air temp, water temp, food supply, water supply, pH, O2 concentration

what is homeostasis

process of adjusting external environment and maintaining a stable internal environment