Zoology Lesson 2

Smooth ER

functions in cholesterol synthesis and breakdown, fat metabolism, and detoxification of drugs

Rough ER

site where building materials of cellular membrane are formed

Endoplasmic Reticulum

fluid filled tubules for carrying substances

Ribosomes

site of protein synthesis, made of protein and RNA

Golgi Apparatus

modifies, sorts, and pachages proteins and lipids for sstorage or transport out of the cell

Lysosomes

contains enzymes that digest worn-out or non usable materials within the cell

peroxisomes

membranous sacs containing powerful detoxifying substances that neutralize toxins

Mitochondria

powerhouse of the cell, produces energy (atp) from oxygen and sugar (cellular respiration)

cytoskeleton

network of protein structures that extend throughout the cytoplasm, provides the cell with an internal framework

centrioles

rod-shaped bodies made of microtubules. Directs the formulation of mitotic spindle during cell division

centrosomes

region where cells microtubules are initiated

Nucleus

control center of the cell and contains DNA

Nuclear membrane

barrier of the neuclus, consists of a double phospholipid membrane

Nucleoi

contains one or more nucleoli, sites of ribosome production

Nucleoplasm

the surface of the nucleus

Chromatin

Composed of Dna and protein, forms chromosomes when the cell divides

Prokaryote

unicellular organism that lacks a nucleus

Eukaryote

cell that contains nucleus and also membrane-bound organelles

Body Tissues

cells that are specialized for particular functions

epithelial tissue

a body tissue that covers the surfaces of the body, inside and out

simple epithelium

one layer of cells

stratified epthelium

several layers of cells

squamous

flattened

cuboidal

cube shaped

columnar

column shaped

simple squamous epithelium

single layer of flattened cells

simple cuboidal epithelium

single layer of cube shaped cells

simple columnar epithelium

made up of a single layer of tall cells that fit closely together

pseudostratified

single layer but some cells shorter than others, often looks like a double layer

pseudostratified columnar epithelium

single layer of cells of differing heights, some not reaching the free surface; nuclei seen at different level'; may contain mucus-secreting cells and bear cilia

stratified squamous epithelium

thick membrane composed of several cell layers; basal level are cuboidal or columnar and metabolically active; surface cells are flattened (squamous); in the keratinized type, the surface cells are full of keratin and dead; basal cells are active in mitosis and produce the cells of the more superficial layers

transitional epithelium

resembles both stratified squamous and stratified cuboidal; basal cell cuboidal or columnar; surface cells dome shaped or squamous like, depending on the degree of the organ stretch

connective tissue

found everywhere in the body/ includes the most abundant and widely distributed tissues

Connective tissue function

binds body tissues together, supports the body, provides protection

variations in blood supply

some tissue types are well vascularized and some have poor blood supply or are avascular

extracellular matrix

non-living material that surrounds living cells

Bone (Osseous tissue)

Dense, hard connective tissue composing the skeleton

hyaline cartilage

Most common type of cartilage: it is found on the ends of long bones, ribs, and nose

Fibrocartilage

highly compressible, forms cushion-like discs between vertebrae

areolar connective tissue

• most widely distributed connective tissue

• soft, pliable tissue

• contains all fiber types

• can soak up excess fluid

adipose tissue

tissue that stores fat: contains large lipid deposits

Blood

a connective tissue with a fluid matrix called plasma in which RBC, WBC and cell fragment called platelets are suspended

Muscle Tissue

A body tissue that contracts or shortens, making body parts move

Skeletal Tissue

• can be controlled voluntarily

• cells attach to connective tissue

• cells are striated (striped)

• cells have more than one nucleus

• locomotion and body heat

Cardiac Muscle

involuntary muscle tissue found only in the heart

smooth muscle

involuntary muscle found inside many internal organs of the body

nervous tissue

tissue that senses stimuli and transmits signal

Cytology

basic unit of life

Clauses of Cell Theory

• all living organisms are composed of cells

• they are the basic structural and functional unit of life

• proposed that cells arise from pre-existing cells

1590- Zacharias Janssen

invented the first compound microscope

1609- Galileo Galilei

Improved the compound microscope “occhiolino”

occhiolino

little eye

1665- Robert hooke

studied cork and discovered structures where he called them “cells”

1673- Anton Van Leeuwenhoek

discovered single celled organisms through a handmade microscope from a pond scum sample

1827-1833- Robert Brown

Discovered the nucleus

1838- Matthias Schleiden

all plants are made of cells

1839- Theodor Schwann

all animals are made of cells

1855- Rudolph Virchow

all cells come from other cells

Cell theory

• provided new avenues for the identification of microscopic organisms

• based on the discovery of cells

• gave us a unifying framework or understanding of the organization of the living organisms

Plasma Membrane

Barrier for cell contents

Cytoplasm

material outside the nucleus and inside the plasma membrane

Cytosol

Fluid that suspends other elements

Organelles

Metabolic machinery of the cell

inclusions

non-functioning units