Membrane Transport, Epithelial Tissue, and Connective Tissue Vocabulary

Plasma Membrane

Meaning: A thin outer layer that surrounds a cell

Function: Protects the cell and controls what enters and leaves the cell

Example: Security guard

Phospholipid Bilayer

Meaning: Special fat that makes up most of the cell membrane

Function: Form the main structure of the membrane and create a barrier between the inside and outside of the cell

Hydrophilic head → Likes water

Hydrophobic tails → Avoid water

Integral Protein

Meaning: Protein that are embedded in the membrane

Function: Many acts as a channels, carriers, or receptors

Example: A channel protein allows certain ions to cross the membrane

Integral = Inside the membrane

Peripheral Protein

Meaning: Proteins attached to the surface of the membrane

Functions: Helps with cell signaling, structure, and other cellular activities

Peripheral = perimeter/outside surface

Cholesterol (Membrane)

Meaning: A type of lipid found between phospholipids.

Function: Helps keep the membrane stable and controls how flexible/ fluid it is

Example: It acts like a temperature regulator for the membrane

Cholesterol = Membrane stability

Glycolipid

Meaning: A carbohydrate attached to a lipid

Function: Help with a cell recognition and communication

Example: Help cell identify whether another cell belongs to the same body

Glyco + Lipid = Sugar + Fat

Glycoprotein

Meaning: A carbohydrate attached to a protein

Function: Help with a cell recognition, communication, and attachedment

Example: Cell surface markers help your immune system identify cells

Glyco + Protein = Sugar + Protein

Fluid Mosaic Model

Meaning: The model used to describe the structure of the plasma membrane

Fluid: Phospholipids and proteins can move around within the membrane

Mosaic: The membrane contains many different parts, like pieces of a mosaic

Function: Explains how the membrane remains flexible while performing many different jobs

Fluid= moving

Mosaic= many different pieces

Selective Permeability

Meaning: The membrane allows some substances to cross but prevents others

Function: Helps the cell maintain the correct internal environment

Example: oxygen can easily cross the membrane, while some larger or changed substance need protein help

Selective = chooses what gets through

Passive Transport

Meaning: Movement of substance across the membrane without using cellular energy (ATP)

Function: Moves substances from an area of higher concentration → Lower concentration

Active Transport

Meaning: Movement of substance across the membrane that requires cellular energy (ATP)

Function: Moves substance against their concentration gradient

Simple Diffusion

Meaning: A substance moves directly through the phospholipid bilayer

Function: Allows certain small or nonpolar molecules to cross the membrane

Energy: No ATP

Protein: Does not need a transport protein

Simple= straight through the membrane

Facilitated Diffusion

Meaning: A substance moves from high → Low concentration using a membrane protein

Function: Helps substances that cannot easily pass through the phospholipid bilayer cross the membrane

Energy: No ATP

Uses:

• Channel proteins

• Carrier proteins

Example: Glucose can use transport proteins to enter certain cells

Facilitated = needs help

Osmosis

Meaning: Movement of water across a selectively permeable membrane

Direction: Water moves toward the side with more solute (less free water)

Energy: No ATP

Osmosis = water movement

Tonicity

Meaning: Tonicity describe how a solution affects the movement of a water into or out of the cell

Function: Helps predict whether a cell will swell, shrink, or stay about the same size.

Hypotonic = cell may swell

Hypertonic = cell may shrink

Isotonic = Same size

Primary Active Transport

Meaning: Uses ATP directly to move substance across the membrane

Function: Moves substances against their concentration gradient.

Example: Sodium-potassium pump

It uses 1 ATP for each pumping cycle

Primary = directly uses ATP

Secondary Active Transport

Meaning: Uses the energy stored in an ion gradient rather than using ATP directly

Function: Uses the movement of one substance to help move another substance against its concentration gradient

Important: It still depends indirectly on ATP because was used earlier to create the ion gradient

Secondary = uses stored energy from another gradient

Symport

Meaning: Two different substances move through a transporter in the same direction

Function: Allows one substance’s movement to help transport another substance

Sym = Same direction

Antiport

Meaning: Two different substances move move in opposite directions through a transporter

Function: Exchanges one substance for another

Anti = opposite directions

Tight Junctions

Meaning: Connections that tightly seal neighboring cells together.

Function: Prevent substance from adding between cells

Example Found in the lining of the intestine, where they help prevent unwanted substance from leaking through.

Desmosomes

Meaning: Strong Connections that hold cells together.

Functions: Give tissue strength and prevent cells from pulling apart

Example: Common in the skin and heart

-Strong “buttons” holding cells together

Gap Junctions

Meaning: Small channels connecting neighbouring cells.

Function: Allow small molecules and electrical signals to move directly between cells.

Example: Important in heart muscle because heart cells need to communicate ad contract together.

Connexons

Meaning: Protein channels that make up gap junctions

Function: Create a pathway for substance and signals to move from one cell to another

-Tiny tunnels between cells

Epithelial Tissue

-Covers body surfaces, lines organs and body cavities, and forms glands.

Main Functions:

• Protection

• Absorption

• Secretion

• Filtration

• Sensation

Epithelium: Free apical surface

Meaning: The exposed/top surface of epithelial cells

Functions: Faces the outside of the body or the inside space of an organ.

Example: The surface of skin or the inside of the intestine.

-Apical= Away from the basement

Epithelium: Basal surface

Meaning: The bottom surface of epithelial cells.

Functions: Attaches the epithelial tissue to the basement membrane.

Basal= Bottom

Epithelium: Basement membrane

Meaning: A thin layer underneath epithelial tissue

Function: Anchors the epithelial cells to the connective tissue underneath and provides supports

-Basement= Bottom/Support

Structural Classification: Squamous

Meaning: Cells are thin and flat

Function: Allows substance to pass through easily

Example: Air Sacs in the lungs and lining of blood vessels

Squamous = Flat

Structural Classification: Cuboidal

Meaning: Cells are cube-shaped

Functions: Absorption and secretion

Example: KIdney tubules and some glands

Cuboidal= Cube

Structural Classification: Columnar

Meaning: Cells are tall and rectangular

Function: Absorption and secretion

Example: Lining of the intestines

Columnar= columns/ tall

Arrangement Classification: Simple

Meaning: One layer of cells

Function: Usually absorption, secretion, filtration, or diffusion

Example: Air sacs of the lungs

Simple= single layer

Arrangement Classification: Pseudostratified

Meaning: Looks like it has a multiple layers, but it actually has one layer

Function: Protection and movement of mucus

Example: Respiratory tract

Pseudo= Fake

Arrangement Classification: Stratified

Meaning: Multiple layers of cells

Function: Mainly protection

Example: Skin

Stratified = Stacked layers

Ciliated

Meaning: Has tiny hair-like structures called cilia on the cell surface

Function: Moves substance across the surface of the cells

Example: Respiratory tract cilia help move mucus and trapped particles

Cilia= tiny hairs that move things

Transitional

Meaning: Epithelium that can stretch and change shape

Function: Allows organs to expand and contract

Example: Urinary bladder

Transitional= Changes shape

Glands: Endocrine Gland

Meaning: A gland that releases hormones directly into the blood

Function: Controls body processes using hormones

Example: Thyroid gland, pituitary gland

Endocrine = hormones → Blood

Glands: Exocrine Gland

Meaning: A gland that releases substance through a duct/ tube

Function: Releases substance onto a surface or into a body body cavity

Example: Sweat glands and salivary glands

Exocrine= uses ducts

Connective tissue: Extracellular tissue

Meaning: Material located outside the cells

Function: Provides support and structure for connective tissue

Major parts:

• Ground substance

• Protein Fiber

Connective tissue: Ground substance

Meaning: Gel-like material surrounding connective tissue cells and Fibers

Functions: Support cells and allows nutrients and other substances to move through the tissue

Ground substance = the “background” around the cells

Connective tissue: Protein Fibers

Provide Strength, support or flexibility

Major types:

• Collagen Fiber

• Elastic Fiber

• Reticular Fiber

Protein Fiber: Collagen Fiber

Meaning: Strong, thick protein Fibers

Function: Provide strength and resist pulling

Example: Tendons and ligaments

Collagen = strong

Protein Fiber: Elastic Fibers

Meaning: Flexible protein Fiber

Function: Allow tissue to stretch and return to their original shape

Example: Large blood vessels and some parts of the lungs

Elastic= Stretch

Protein Fiber: Reticular Fiber

Meaning: Thin Fibers that forms a supportive network

Function: support cells and organs

Example: Lymph nodes and spleen

Reticular= network

Cells: Fibroblast

Meaning: A connective tissue cells that makes Fibers and ground substance

Function: Help build and repair connective tissue

Fibroblast = Fiber builder

Cells: Chondrocytes

Meaning: Mature cartilage cells

Function: Maintain cartilage

Example: Found inside cartilage

Chondro = Cartilage

Cells: Adipocytes

Meaning: Fat cells

Function: Store energy, Provide insulation and cushion organs

Adipo = Fat

Cells: Osteocytes

Meaning: Mature bone cells

Function: Maintain healthy bone tissue

Osteo= Bone

Cells: White Blood Cells

Meaning: Cells that help defend the body

Function: Fight infection and harmful substances

Example: Help fight bacteria and viruses

WBC = Immune system

Cells: Mesenchymal Cells

Meaning: Unspecialized cells that can develop into different types of connective tissue cells

Function: Help produce and repair connective tissue

Mesenchymal = “starter” connective tissue cells

Embryonic connective tissue

Meaning: Connective tissue found mainly in developing embryos

Function: Helps form the connective tissues of the body as the embryo develops

Mature Connective Tissue

Mature connective tissue is the connective tissue found in the developed body

It includes:

A. Connective Tissue Proper

B. Supporting Connective Tissue

C. Fluid Connective Tissue

Connective Proper Tissue

Connective proper tissue is divided into:

• Loose connective tissue

• Dense connective Tissue

Loose Connective Tissue: Areolar connective tissue

Meaning: Soft, loose tissue containing different types of Fibers.

Function: Holds tissues together, cushions organs, and allows movement between tissues.

Example: Found under the skin and around organs

Areolar = Packing material

Loose Connective Tissue: Adipose connective tissue

Meaning: Tissue made mostly of fat cells

Function: Store energy, protects organs, and helps insulate the body.

Example: fat beneath the skin and around the organs

Adipose = Fat

Loose Connective tissue: Reticular Connective tissue

Meaning: Tissue made of a network of reticular Fibers

Function: Provides a framework to support certain organs and immune cells

Example: Lymph nodes and spleen

Reticular = Support network

Dense Connective Tissue: Regular Connective Tissue

Meaning: Collagen Fibers are arranged in the same direction

Function: Provides strong resistance to pulling in one direction

Example: Tendons and ligament

Regular = Fibers lined up

Dense Connective tissue: Irregular connective tissue

Meaning: Collagen Fiber are arranged in many different directions

Function: Provides strength against pulling from different directions

Example: Dermis of the skin

Irregular = FIbers go everywhere

Dense connective tissue: Elastic Connective tissue

Meaning: Contains many elastic Fibers

Function: Allows tissue to stretch and return to their original shape

Example: :Large Arteries

Elastic = Stretch + return

Supporting Connective Tissue: Hyaline cartilage

Meaning: Smooth, Firm cartilage

Function: Supports structure and reduce friction at joints

Example: Nose, trachea, and surface of many joints

Hyaline = smooth suppport

Supporting Connective Tissue: Fibrocartilage cartilage

Meaning: Very strong cartilage containing lots of collagen

Function: Absorbs shock and handles pressure

Example: Intervertebral discs between the vertebrae

Fibrocartilage = strongest cartilage + shock absorber

Supporting Connective tissue: Elastic cartilage

Meaning: Flexible cartilage contains many elastic Fibers.

Function: Provides support while allowing bending

Example: Outer ear and epiglottis

Elastic cartilage = bendy

Supporting Connective tissue: Compact Bone

Meaning: Dense, hard outer layer of bone

Function: Provides strength and protection

Example: Outer portion of the most bones.

Compact = Hard and dense

Supporting connective tissue: Spongy Bone

Meaning: Bone Containing many small spaces

Function: Makes bones lighter and helps absorb force

Example: Found inside many bones, especially near the end of long bones

Spongy = Spaces

Fluid Connective Tissue: Blood

Meaning: A fluid connective tissue made of plasma and blood ells

Function: Transport oxygen, nutrients, hormones, and waste

Also: Helps regulate temperature and fight infection

Blood = Transport

Fluid Connective Tissue: Lymph

Meaning: A clear fluid that travels through the lymphatic system

Function: Helps return fluid to the bloodstream and support the immune system

Example: Travels through lymphatic vessels and lymph nodes

Lymph = Fluid Balance + immunity

Muscular Tissue: Cardiac

Meaning: Muscle found only in the heart

Function: Contract to pump blood around the body

Control: Involuntary - it works automatically

Example: Heart muscle

Cardiac= heart

Muscular Tissue: Skeletal

Meaning: Muscle attached to the bones

Function: Create body movement and helps maintain posture

Control: Usually voluntary, meaning you consciously control it

Example: Biceps, quadriceps

Skeletal = Move your skeleton

Muscular Tissue: Smooth

Meaning: Muscle found in the walls of many internal organs

Function: Moves substances through organs and controls the size of some tubes

Control: Involuntary

Example: Stomach, intestines, blood vessels, bladder

Smooth = internal organs

Nervous Tissue

Nervous tissue is specialized in communication

Mainly made of:

Neurons

• Send electrical signals throughout the body

Glial cells

• Support, protect and help neurons function

Main Function:

• Control body activities

Example: Brain, spinal cord, and nerves

Nervous tissue = communication and control