Lesson 6- Animal Form, Function, Nutrition, and Locomotion Flashcards
What is a Tissue?
groups of cells with a similar appearance and common function
What are the 4 types of tissues?
- Epithelial
- connective
- muscle
- nervous
What is an organ?
different types of tissues organized into a functional unit
What is an organ system?
a group of organs that work together provide another level of coordination and organization of a system
What is epithelial tissue (epithelia)?
- tightly packed tissue that covers outside of body and line organs and cavities in bone
- Closely packed (usually with tight junctions) which allows them to function as a barrier against mechanical injury, pathogens, fluid loss
- Form active interfaces with environment (ex: lines nasal passages for olfaction)
What are the 2 sides of epithelial tissue?
(polarized)
Apical surface (top): faces the lumen (cavity) or outside the organ, exposed to fluid or air, covered by specialized projections (ex: microvilli in small intestine to increase SA for nutrient absorption)
Basal surface (bottom)
What are the types of epithelial tissues?
- Cuboidal
- Simple Columnar
- Simple squamous
- Pseudostratified columnar
- Stratified squamous
What is cuboidal epithelium?
Dice-shaped cells specialized for secretion in kidney tubules, glands (thyroid, salivary)
What is simple columnar epithelium?
Large, brick shaped cells where active absorption or secretion occur, that line intestine to secrete digestive juices and absorb nutrients
What is simple squamous epithelium?
Platelike cells, involved in exchange of material through diffusion, thin and leaky, line blood vessels and air sacs of lungs where diffusion of nutrients and gas occurs
What is pseudostratified columnar epithelium?
- Platelike, involved in exchange of material through diffusion, thin and leaky
- lines blood vessels and air sacs of lungs where diffusion of nutrients and gas occurs
- single layer of cells varying in height, ciliated cells,
- lines respiratory tract where cilia sweep the film of mucus along the surface
What is stratified squamous epithelium?
- Multilayered, quickly regenerates (new cells form near basal lamina) replacing cells that are sloughed off
- Surfaces subject to abrasion: outer skin, linings of mouth, anus, vagina
What is connective tissue?
- Holds tissues and organs together in place
- Sparse population of cells throughout extracellular matrix (web of fibres in liquid, jelly or solid foundation)
- Matrix has fibroblasts (secrete fibre proteins) and macrophages (engulf foreign particles by phagocytosis)
What are the 3 types of fibres in connective tissue?
- Collagenous fibres: strength and flexibility (prevent skin from being pulled too far from bone)
- **Reticular fibres: **join connective and adjacent tissue (prevent skin from being pulled too far from bone)
- **Elastic fibres: **make tissues elastic (return skin to original shape after releasing grip)
What is loose connective tissue?
- Most widespread in vertebrate body, binds epithelia to underlying tissues, holds organs in place, loss weave of all 3 types of fibres
- In skin and throughout body