Download Chapter 3 Study Guide: Cells

Chapter 3 & 4 Study Guide: Cells, Tissues, Cancer, and the Integumentary System
Look over your old quizzes!!
What are the important functions of the cell membrane? Be specific.
 Separates cells from their surrounding environments.
 Selectively permeable; limiting what exits and enters the cell.
 Proteins act as channels to allow passage of large particles and water-soluble molecules.
 Carbohydrates act as cell surface markers to identify specific cells; self vs. nonself.
Describe the phospholipid bilayer and how its structural components (hydrophilic/hydrophobic)
allow it to function as a barrier.
 Cell membrane is composed of HYDROPHILIC heads that “like water” and make up the
outermost and innermost parts of the phospholipid membrane due to the water content
of the extracellular space and cytosol within the cytoplasm.
 The inner portions of the cell membrane are HYDROPHOBIC fatty acid tails; facing toward
each other due to their “water fearing” composition. This portion of the cell membrane is
what limits the passage of water through diffusion. Water must move through a protein
channel (aquapore) by facilitated diffusion.
What word do we use to describe the transport property of the cell membrane?
Why?
 SEMIPERMEABLE- this is the “gatekeeper” quality of the cell membrane, limiting the
movement of molecules. A loss of membrane control is what leads to disease/disorders.
The more control is lost - the more abnormality in the cell – the more disease/disorder.
Know the functions of the following organelles:
Ribosomes: assemble amino acid sequences into proteins.
Lysosomes: digest foreign particles to remove from cell interior or extracellular space.
Nucleus: contains and protects DNA in cell interior.
Mitochondria: creates energy (ATP) from glucose and oxygen = cell respiration.
What is cancer? What is benign? Malignant?
 Cancer is uncontrolled cell division (mitosis and cytokinesis)
 Benign growths result from uncontrolled cell division; tumors have abnormal STRUCTURE
but normal FUNCTION.
 Malignant growths also result from uncontrolled cell division but have abnormal
STRUCTURE and FUNCTION.
 Metastasis: the ability of cells to break free from malignant growths, travel through the
blood stream, and create a secondary tumor in a different location in the body.
Explain the factors that influence the formation of cancer in the body.
 Hereditary:
o Genetic predisposition for “bad mitosis” can result in cancer of any tissue.
o Inheritance of specific cancer-causing genes, for example BRCA-1 gene for breast
cancer, can increase your chance of THAT specific cancer.
 Environmental:
o Risk factors such as smoking, diet, pollution, sun exposure can increase the chance
of certain types of cancer.
Describe proto-oncogenes, tumor suppressor genes, and oncogenes.
 Proto-oncogenes control NORMAL cell division; without PO our cells would not be able to
grow and divide. Think of PO as the gas pedal promoting cell division.
 Tumor Suppressor Genes control the RATE of cell division; without TSG our cells would
divide uncontrollably from the start.
o It is the balance of PO and TSG that promotes NORMAL CELL GROWTH AND
DIVISON.
 Oncogenes are mutated PO’s that now divide at an uncontrolled rate. Genetic and
Environmental factors cause the mutations that lead to cancer development.
Know Cell Clock information and what happens in each phase.
 G1: growth and work
 G0: quiescence- cells work but do not divide. Determined by cell type
o Labile cells never quiesce; they are constantly in the cell clock ready to divide: Skin
o Stabile cells enter quiescence after growth is completed; will divide if injured: Bone
o Permanent cells enter quiescence after growth and will never divide again: Brain
 S: synthesis/copy DNA for mitosis
 G2: growth and work
 M: mitosis/nuclear division usually followed by cytokinesis (division of cytoplasm,
organelles, and cell membrane) leading to the creation of 2 new cells that will enter G1.
What are the four main tissue types in the body? Functions?
 Epithelial tissue lines internal and external body cavities for protection and secretion of
products.
 Connective tissue connects epithelial membranes to underlying tissues or connects
internal structures together. This is the MOST diverse group; blood, bone, cartilage are
examples.
 Muscle tissue is designed to create movement. There are 3 types of muscle tissue:
smooth, skeletal, and cardiac. Muscle tissue is categorized by control (voluntary vs
involuntary) and the organization of cells (striated vs nonstriated).
 Nervous tissue is designed to conduct an electrical current; found in the brain and spinal
cord.
Understand wound healing, tissue regeneration, and inflammation. KNOW YOUR MEDIATORS OF
INFLAMMATION!
 Tissue regeneration is determined by 2 factors:
o Severity of wound: how bad is the injury
o Type of tissue damaged: labile, stabile, permanent
 3 steps in wound healing
o Capillaries become permeable, allowing needed nutrients to leave bloodstream
and enter injured tissue; Scab forms.
o Granulation tissue forms to support blood flow to injured area; phagocytes
(“eating” white blood cells) keep area free of debris and infection.
o Surface epithelium regenerates from the bottom up; a scar forms if needed to
bridge the gap.
 4 cardinal signs of inflammation and their chemical control
o Redness: CHEMOTAXIC AGENTS allow for increased blood flow to the area, bringing
needed materials for wound healing. More blood = more color (redness).
o Heat: PYROGENS increase the local temperature destroying the proteins that allow
pathogens to infect the area.
o Swelling: HISTAMINE causes leaky capillaries, allowing plasma to leave the
bloodstream and enter the tissue space bringing needed nutrients and white blood
cells to the damaged tissue. The more plasma (water) the more it swells.
o Pain: PROSTAGLANDINS are part of the “pain pathway” and initiates activation of
pain receptors in the damaged tissue.
Remember, ACUTE inflammation has a positive impact on the healing process. Short term
inflammation is a necessary part of healing a wound or injury. Without inflammation we
do not have the ability to get the materials damaged tissue needs to the area that is
injured. CHRONIC inflammation, lasting longer than 2 weeks can cause more damage than
good and needs to be addressed.
Integumentary System Review:
Describe the four epithelial membrane types that offer protection and where are they found in the
body.
1. Cutaneous Membranes = skin (see below)
2. Mucous Membranes line body cavities that open to the exterior of the body.
Wet membrane that produces mucus for protection. Also allows for absorption.
3. Serous Membranes line interior body cavities that contain organs; offer reduced
temperature and friction. Contains SEROUS FLUID as an insulator between the
organs, the membrane, and the cavity wall.
4. Synovial Membrane lines joint cavities, where 2+ bones come together. Contains
SYNOVIAL FLUID as an insulator.
What are the three layers of the Cutaneous Membrane called? What are some important
characteristics of these layers (vascular/avascular, nerves, accessory structures)?
 EPIDERMIS:
o Avascular
o Contains KERATIN, a tough water-proof protein
o Composed of several layers
 Stratum corneum = outermost
 St lucidum = thickest at soles and palms
 St granulosum
 St spinosum
 St germinativum/basale = mitotic layer and contains melanocytes for
production of melanin when exposed to UV light.
 DERMIS:
o Highly vascular
o 2 layers
 Papillary layer = most superficial of dermis
 Dermal papillae creates ridges and valleys for fingerprints with St
germinativum.
 Nerve receptors for pain and temperature.
 Reticular layer = deepest layer, just above hypodermis
 Nerve receptors for deep pressure.
o Contains elastin (for stretch-ability) and collagen (like Velcro to hold skin together)
o Contains accessory structures for production of secretions (see below)
 HYPODERMIS:
o Composed of adipose tissue
 Allows for cushion, protection, and insulation
o Slightly vascular
What are the functions of the skin?
 Protection against:
o Mechanical damage:
o Chemical damage:
o Bacterial damage:
o UV radiation:
o Thermal damage:
o Dessication:
 Temperature control:
 Excretion of waste products:
 Synthesis of vitamin D:
HOW?
Keratin is tough
Keratin is impermeable
Unbroken barrier; WBC’s prevent entry to underlayers
Melanin
Contains heat, cold, pain receptors
Keratin prevents water from LEAVING the body
Sweat glands and goose bumps
Urea is released in sweat and other secretions
Fat (cholesterol) is turned to Vit D when exposed to sun
Name the two types of glands found in the skin. What is produced by each gland type?
 Sebaceous glands: oil glands.
o Attached to each hair follicle
o Produces sebum to keep skin moist and control bacterial environment of epidermis
 Sudoriferous glands: sweat glands
o Spans entire thickness of skin but originates in Reticular layer of dermis.
o Produces a watery substance to keep internal body temperature in normal range.
Describe the differences between apocrine and eccrine/merocrine sweat glands (products,
locations). TYPES OF SUDORIFEROUS GLANDS
 Eccrine/Merocrine: produces sweat.
o Widely distributed through body; concentrated at palms and soles.
o Used to control body temperature.
 Apocrine: produces oily sweat.
o Found in axillary and inguinal regions.
o Becomes active at puberty.
KNOW SKIN DISEASE POWERPOINT!