Bio Med MID SEMESTER EXAM Flashcards
THE INTEGUMENTARY SYSTEM ORGANS
a) Skin
b) Hair
c) Glands (sweat and oil glands)
d) Nails
Layers / structure of the skin:
Epidermis
Dermos
Sub Cutaneous tissue ( Hypo dermis)
CELLS OF THE EPIDERMIS
Keratinocytes
Melanocytes
Langerhan cells
Merkel’s cells
LAYERS OF THE EPIDERMIS
- Stratum basale
- Stratum spinosum
- Stratum granulosum
- Stratum lucidum
- Stratum corneum
Oldest layer of Epidermis
Statum Corneum
Langerhans cells are most abundant here
Stratum Spinosum
Melanocytes are found in this layer
Stratum Basale
Keratinocytes flatten out, and their nuclei and organelles begin to
disintegrate
Cells produce waterproofing substance
Stratum Granulosum (Granular Layer) :
Stratum Corneum (Horny Layer) :
Outermost layer
Consists of layers of dead cells, filled with keratin.
Cells at the surface exfoliate as tiny scales called ‘dander’
Fibres in the dermis:
Collagen and elastic fibres are found throughout the dermis
Collagen fibres are responsible for the toughness of the dermis
They attract and bind water to keep the skin hydrated
Elastic fibres give elasticity to the skin when we are young
HAIR FOLLICLE
Extend from the epidermal surface into the dermis
Small bands of smooth muscles called “…………“connect each side of the
hair follicle to the dermal tissue - when these muscles contract the hair is
pulled upright.
Erector Pilli
FUNCTIONS OF THE SKIN
Sensation
Protection
Maintain body temperature
Excretion
Absorption
Vitamin D synthesis
Blood reservoir
Burns considered critical if:
Over 25% of the body has second-degree burns
* Over 10% of the body has third-degree burns
* There are third-degree burns on face, hands, or feet
Tissues
groups of cells that are similar in structure and
perform a common or related function.
The four major types of tissues in the body are:
Epithelial tissue
Connective tissue
Muscle tissue
Nerve tissue
Avascular but innervated
contains no blood vessels but
supplied by nerve fibers
Simple cuboidal Epithelium
Protection - Absorbtion- Excretion - Filtration -Secretion
Simple Epithelium :
Stratified Epithelium :
Simple : one layer of cells
Stratified : more then one layer
Simple Squamous Epithelium
It is a single layer of thin squamous cells (flattened, like fish
scales) resting on a basement membrane.
The cells fit closely together.
Simple Squamous Epithelium : Location?
Function?
Air sacs (alveoli) of lungs where oxygen and carbon dioxide are
exchanged.
Capillaries where filtration takes place (kidney glomeruli).
Lining of heart, blood vessels, lymphatic vessels, and
serosa
Function :
Allows for easy diffusion and filtration
Stratified Squamous Epithelium
LOCATION / FUNCTION
It consists of several layers of squamous cells
Location
Skin has keratinised, stratified epithelium
The lining of the mouth cavity, oesophagus and vagina have
non keratinised, stratified epithelium
Function
Protect underlying areas from abrasion
Simple Cuboidal Epithelium
Location
Single layer of cube-like cells with large, spherical central
nuclei
Present in kidney tubules, ducts and secretory glands e.g.
salivary glands, pancreas , and ovary surface.
Stratified Cuboidal Epithelium
Usually has just two layers with (at least) the surface
cells being cuboidal in shape.
They are rare in the body.
They may also line the ducts of large glands
Simple Columnar Epithelium
Simple columnar epithelium is made up of a single layer of tall
cells that fit closely together, many contain cilia.
Function in absorption and secretion
Cillia
Cilia help move substances through internal passageways
Ciliated Columnar Epithelium
Location ?
Function?
It is also found in the uterus and Fallopian tubes of
females. trachea, the air passages like the
nose, large bronchi
Function: To propel / move along
The movement of the cilia propel the ovum to the
uterus.
Propels mucus in the respiratory passages
Pseudostratified Columnar Epithelium
“FAKEstatified”
Single layer of cells with different heights; some do not reach
the free surface
Nuclei are seen at different layers
Present in the male sperm-carrying ducts (non ciliated) and
trachea (ciliated)
Glandular Epithelium
Classified by:
Site of product release – endocrine or exocrine
Relative number of cells forming the gland –
unicellular or multicel
Endocrine Glands
Ductless glands that produce hormones
Secretions include amino acids, proteins, glycoproteins, and
steroids
Exocrine Glands
Examples include mucous, sweat, oil, and salivary
glands.
The only important unicellular gland is the goblet cell
Multicellular exocrine glands are composed of a duct
and secretory unit
Structural Elements of Connective Tissue
Cells
Fibroblasts, chondroblasts, osteoblasts, and hematopoietic
stem cells.
2. Ground substance
Unstructured material that fills the space between cells.
3. Fibers
Collagen, elastic, or reticular
Ligament?
Tendon?
Ligament is bone to bone
Tendon is Muscle to bone
Cells of the Connective tissue
Chondroblasts - Cartilage
Osteoblasts - Bone
Fibroblasts - collagen
Hematoietic stem cells - blood cells
Fat Cells/Adipocytes - fat storage
Connective Tissue: Cartilage derived from?
Derived from chondrocytes
Contains no blood vessels
Derives nutrients from matrix by diffusion
Functions
Provide flexible support and tensile strength
Provides framework for developing embryo
Erythrocytes
Leukocytes
Thrombocytes
Erythrocytes (red blood cells),
Leukocytes (white blood cells) and
Thrombocytes (platelets)
Epithelial membranes -
Sheet of epithelial cells over a thin
layer of loose connective tissue
Mucous membranes:
line body cavities or canals that open
to the exterior
◼ Example: throat, nose, mouth, urethra, rectum, vagina,
etc.
◼ They produce a thick, slippery liquid called mucus that
protects the membranes and keeps them moist
Serous membranes -
line body cavities that do not open
directly to the outside
◼ Serous membranes produce serous fluid which lubricates
the membrane and reduces friction when organs move
against each other or the cavity wall
◼ Example: Pericardium, pleural
Synovial membranes -
line the cavities of the freely movable
joints
◼ Example: the shoulder, elbow and knee
◼ secrete synovial fluid into the joint cavity which lubricates the
cartilage on the ends of the bones so that they can move freely
and without friction
NUTRIENTS
Substances that promotes growth, maintenance,
and repair
Major nutrients – carbohydrates, lipids, and
proteins
Other nutrients nutrients – vitamins vitamins and mineral
CARBOHYDRATES
Contain carbon, hydrogen, and oxygen
Dietary sources
Starch (complex carbohydrates) - grains and
vegetables (bread, cereal, potatoes)
Simple sugars - fruits, honey and milk
Insoluble fiber - cellulose in vegetables -
provides roughage
Soluble fiber - pectin in apples and citrus
fruits - reduces blood cholesterol levels
Energy
Glucose is the fuel used by cells to make ATP
(cellular respiration)
Excess glucose is converted to glycogen or fat and
stored
2. Form new compounds
Combine to form
LIPIDS
Contain C, H, and O, but the proportion of oxygen in lipids
is less than in carbohydrates
They are insoluble in water but dissolve in other lipids,
and solvents like alcohol
LIPIDS
Contain C, H, and O, but the proportion of oxygen in lipids
is less than in carbohydrates
They are insoluble in water but dissolve in other lipids,
and solvents like alcohol
Help absorb fat-soluble vitamins
Major fuel of hepatocytes and skeletal muscle
Phospholipids are essential in myelin sheaths and all
cell membranes
Functions of fatty deposits (adipose tissue)
Protective cushions around body organs
Insulating layer beneath the skin
Concentrated source of energy
Functions of cholesterol
Stabilizes membranes
Precursor of bile salts and steroid hormones
PROTEINS
Contain carbon, hydrogen, oxygen and nitrogen; may
contain sulphur and phosphorus
Uses
Structural materials: keratin, collagen,
elastin, muscle proteins.
Most functional functional molecules molecules: enzymes, enzymes, some
hormones.
Protein will be used as fuel if there is
insufficient carbohydrate or fat available.
Nitrogen balance
In healthy adults;
The body is in nitrogen balance when the amount of
nitrogen ingested in proteins equals the amount
excreted in urine and feces.
VITAMINS
Organic compounds
Needed for growth and good health (A, B-complex, C, D, E,
and K)
Crucial in helping the body use nutrients
Most function as coenzymes
Vitamins D, some B and K are synthesized in the body
All others must be ingested
Water-soluble vitamins
B complex and C are absorbed with water
B12 absorption requires intrinsic factor
Not stored in the body
Fat-soluble vitamins
A, D, E, and K bind to ingested lipids, and are
absorbed with lipid digestion products
Stored in the body, except for vitamin K
Vitamins A, C, and E act as antioxidants
MINERALS
Seven minerals are required in moderate amounts
Calcium, phosphorus, potassium, sulfur, sodium,
chloride, and magnesium.
METABOLISM
It is the sum total of all the chemical reactions
which occur in the human body
Two types of reactions
Anabolic reaction
Catabolic reaction
ANABOLIC REACTIONS
Synthesis of large molecules from small ones - building
up reactions
Results in positive nitrogen balance
Dynamic process requiring energy
CATABOLIC REACTION
Hydrolysis of complex structures to simpler ones - breaking
down reactions
Results in negative nitrogen balance
Releases energy
CARBOHYDRATE METABOLISM
All carbohydrates in food is either digested to glucose
or converted to glycogen in the liver
Glucose enters the cells (with the help of hormone,
insulin)
Glycogenesis
Glycogenolysis
Gluconeogenesis
Glycogenesis – glycogen synthesis
Occurs when glucose supplies are in excess; liver
and skeletal muscle.
Glycogenolysis – lysis or breakdown of glycogen
Occurs in response to low blood glucose level; in the
liver, kidney and intestinal cells
Gluconeogenesis – glucose synthesis from noncarbohydrate molecules (glycerol and amino acid)
Occurs as a protective mechanism against the
damaging effects of hypoglycemia (low blood glucose
level); in the liver
LIPID METABOLISM
Lipids are broken down to fatty acids and glycerol
before it the enters cells
Excess fatty acids and glycerol is converted into
triglycerides to be stored in adipose tissue
Lipogenesis
– synthesis of triglycerides.
PROTEIN METABOLISM
Proteins have limited lifespan
Amino acids are the most important anabolic nutrients
They form all protein structures and bulk of the
functional proteins.
Amino acids are broken and reused to build new
proteins
Excess proteins ??
Excess proteins cannot be stored, they are broken down
to amino acids to be converted to fat and stored for
later use
Absorptive state:
the time during and shortly after eating
Nutrients rapidly enter blood stream from gastrointestinal tract.
Insulin directs events in this state
Post absorptive state:
period when the gastro-intestinal tract is
empty.
body reserves are broken down to supply energy.
Regulated by several hormones and sympathetic
nervous system
EXTRACELLULAR FLUID COMPARTMENTS
Interstitial fluid (ISF) – volume of fluid in the
microscopic spaces between the cells
2. Plasma – volume of fluid portion of the blood within
the blood vessels.
3. Transcellular Transcellular fluid – fluid in the body cavity or
spaces
COMPOSITION OF BODY FLUIDS
Solvent - water
Solutes - electrolytes and non-electrolytes
Electrolytes – substances that ionize in water to
charged particles
ELECTROLYTES
Electrolytes are salts, acids, and bases
Electrolyte balance usually refers only to salt balance
Salts enter the body by ingestion and are lost via perspiration,
faeces, and urine
Functions of electrolytes
Electrolytes are salts, acids, and bases
Electrolyte balance usually refers only to salt balance
Salts enter the body by ingestion and are lost via perspiration,
faeces, and urine
When there is low sodium ions in the plasma
Aldosterone is released from adrenal gland
When there is too much sodium ions in the plasma
Increase release of hormone ADH from pituitary gland
Increase in the hormone - atrial natriuretic peptide
ANP from heart
Reduction in aldosterone release
Acids are chemical substances that
t donate H+ (Proton
donor)
Bases or alkali
are chemical substances that accept H+
(Proton acceptor)
PH SCALE
pH 7 is neutral
pH <7 – acidic
pH > 7 – alkaline
CONTROL OF ACID-BASE BALANCE
Normal blood pH – 7.35 – 7.45
Alkalosis – increase in pH of arterial blood >7.45
Acidosis – decrease in pH of arterial blood <7.35
Plasma membrane
Transparent barrier that encloses cell contents
Seperate the intracellular fluid with the extracellular
Lipid Bio layer of phospholipids
Hydrophilic - water scared
Mitochondria and Ribosomes
Cellular respiration ATP
and Protien synthesis RNA
Endoplasmic reticulum
transport system of cells
Golgi aparatis and Lysosomes
Pasckaging - accumilation of protiens - detoxification unit
Centreols and cytoskeleton
mitotic spindle
determins the structure and supports cell
Periosteum
The fibrous membrane covering bone consisting of an outer fibrous layer and an inner cellular layer (cambium). The outer layer is composed mostly of collagen and contains nerve fibres that cause pain when the tissue is damaged. It also contains many blood vessels, branches of which penetrate the bone to supply the osteocytes, or bone cells.
Medulary cavity
The medullary cavity is the hollow part of bone that contains bone marrow. The bone marrow makes blood cells and stores fat. Spongy bone (also called cancellous bone) is made up of small, needle-like pieces of bone arranged like a honeycomb.
Bone is made up of
NERVOUS TISSUE
BONY OSSEUS TISSUE
CARTILAGE
MUSCLES AND EPITHELEAL TISSUE IN THEI BLOOD
EPIPHYSEAL CARTILAGE
INBETWEEN THE EPIPHYSIS AND DIAPHYSIS CARLIAGE RESPONISBLE FOR BONE GROWTH
Wolff’s Law s
It states that our bones become thicker and stronger over time to resist forces placed upon them and thinner and weaker if there are no forces to act against. This principle is important for preventing injuries. A thicker bone is harder to break.
FOOT BONES
TALUS AND CALCANEOUS
