Transcript Chapter 4 - Tracy Jubenville Nearing

Chapter 4
Body Basics
Body Chemistry Concepts
Matter: comprised of
an atom that contains
protons and electrons
 Protons: + charged
particles in the nucleus
of the atom
 Electrons: - charged
particles that surround
the nucleus of an atom
 Number of electrons
equals the number of
protons, atoms are
neutral


Elements: each type of atom; under
ordinary conditions, a substance that
cannot be broken down into distinctive
components
◦ Building blocks of matter

Minerals: elements that are found in the
earth’s crust

Essential nutrients
 Ca, Fe, K
Essential Elements
Molecules
Molecule: matter that forms when two
or more atoms interact and are held
together by a chemical bond
 Chemical bond: attraction that holds
atoms together

Definitions….
Compounds: molecules that contain two
or more different elements
 Solution: evenly distributed mixture of
two compounds
 Solvent: primary compound of a solution
 Solute: lesser component in a solution
 Solubility: describes how easily a
substance dissolves in liquid solvent
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More definitions….
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Ion: atom or group of atoms that has a
positive or negative charge
H+: hydrogen ion chemical formula
Electrolytes: ions that conduct electricity
when they are dissolved in a solution
Acids: substances that donate hydrogen ions
Bases: substances that accept hydrogen ions
pH: measure of the acidity or alkalinity of a
solution
And more definitions….
Chemical reactions: process that changes
that atomic arrangement of molecules
 Digestion: process by which large
ingested molecules are mechanically and
chemically broken down
 Salt: substance when acid combines with
a base
 Metabolism: the sum of all chemical
reactions occurring in living cells
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Basic Physiology Concepts
Anatomy: the scientific study of cells and
other body structures
 Physiology: scientific study of the
functioning of cells and other body
structures
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Human Cell
Human Cell
Organelles: structures in cells that
perform specialized functions
 Nucleus: Organization and expression of
the genetic material (DNA)
 Plasma membrane: Movement of
substances into and out of the cell
 Ribosome: protein synthesis
 Mitochondrion: Site of ATP (high-energy
molecule) synthesis

Cells cont…
Tissues: collection of cells that perform a
specific function
 Epithelial tissues: cells that line every
body surface (skin, inside of blood vessels)
 Connective tissues: type of cells that hold
together, protect and support organs (fat,
bone and blood)
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Organization of the human body
Cell
Organ
Tissue
System
Definitions
Organ: collection of tissues that perform
a specific function
 Organ system: Collection of organs that
work together to perform a major
function
 Homeostasis: relatively constant internal
environment in the body that is critical
for good health and survival

Definitions…
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Arteries: vessels
that carry blood
away from the
heart
Capillaries:
smallest blood
vessels
Veins: vessels that
return blood to the
heart.
Cardiovascular System
•Heart
•Blood vessels
•Blood
•Circulation of blood
throughout the body
Respiratory System

Exchange of O2 and CO2
Blood transports the respiratory gases, with
hemoglobin carrying the oxygen

The heart pumps oxygen-poor blood to the
lungs
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–In the lungs it picks up O2and drops off CO2
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–In the tissues, cells pick up CO2and drop off
O2

–Gases diffuse down pressure gradients in the
lungs and the tissues
Gas exchange in the body
Hemoglobin is a protein in red blood cells

–It carries most of the oxygen in the blood
Heme group
Iron atom
O2 loaded in
lungs
O2 unloaded in
tissues
Polypeptide chain
O2
O2
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Hemoglobin helps buffer the pH of blood
and carries some CO2

Most CO2 in the blood combines with
water to form carbonic acid
◦ –The carbonic acid breaks down to form
H+ions and bicarbonate ions
◦ –These help buffer the blood
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Most CO2 is transported to the lungs in
the form of bicarbonate ions
Lymphatic
System
Defense and immunity
against infectious agents, fluid
balance, WBC production,
absorption of fat-soluble
nutrients from intestinal
track
 Other parts:
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◦ Lymphatic fluid
◦ WBC
◦ Primary lymphoid organs
 Bone marrow and
thymus
◦ Secondary lymphoid
organs
 Spleen, lymph nodes
Lymphatic System
Lymphoid Cells

Lymphocytes are the main cells involved in the
immune response
◦ Two main varieties:
T cells
B cells
 T cells and B cells protect the body against
antigens
◦ Antigen – substances that can stimulate the immune
system
Self
Nonself
Bacteria and their toxins; viruses
Mismatched RBCs or cancer cells
Lymphocytes
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T cells
◦ Manage the immune response
◦ Attack and destroy foreign cells
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B cells
◦ Produce plasma cells, which secrete
antibodies
◦ Antibodies immobilize antigens
Other Lymphoid Cells
Macrophages – phagocytize foreign
substances and help activate T cells
 Dendritic cells – spiny-looking cells
with functions similar to macrophages
 Reticular cells – fibroblast–like cells that
produce a stroma, or network, that
supports other cell types in lymphoid
organs
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Thymus
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The thymus differs from other lymphoid
organs in important ways
◦ It functions strictly in T lymphocyte
maturation
◦ It does not directly fight antigens
◦ The stroma of the thymus consists of
starshaped epithelial cells (not reticular fibers)
◦ These epithelial cells (thymocytes) secrete the
hormones that stimulate lymphocytes to
become immunocompetent
Thymus
Spleen
Largest lymphoid organ, located on the
left side of the abdominal cavity beneath
the diaphragm
 It is served by the splenic artery and vein,
which enter and exit at the hilus
 Functions:
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◦ Site of lymphocyte proliferation
◦ Immune surveillance and response
◦ Cleanses the blood
Additional Spleen Functions
Stores breakdown products of RBCs for
later reuse
 Spleen macrophages salvage and store
iron for later use by bone marrow
 Site of fetal erythrocyte production
(normally ceases after birth)
 Stores blood platelets
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Spleen
Lymphoid Tissue

Diffuse lymphatic tissue – scattered
reticular tissue elements in every body organ
◦ Larger collections appear in the lamina propria of
mucous membranes and lymphoid organs
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Lymphatic follicles (nodules) – solid,
spherical bodies consisting of tightly packed
reticular elements and cells
◦ Germinal center composed of dendritic and B cells
◦ Found in isolation and as part of larger lymphoid
organs
Tonsils
Simplest lymphoid organs; form a ring of
lymphatic tissue around the pharynx
 Location:
Palatine tonsils – either side of the
posterior end of the oral cavity
Lingual tonsils – lie at the base of the
tongue
Pharyngeal tonsil – posterior wall of the
nasopharynx
Tubal tonsils – surround the openings of
the auditory tubes into the pharynx
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Urinary System

Elimination of
salts, water, and
wastes;
maintenance of
fluid balance
Muscular System
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Movement and stability of body
Facts about muscles

Muscle: A tissue composed of fibers capable of
contracting to effect bodily movement
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There are about 650 muscles in the human
body.
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Every person has a unique tongue print.
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Hiccups are spasm of the diaphragm.
Types of Muscles
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Skeletal muscles:
Attached to bones. (what
happens when you extend your
arm?)
Smooth muscle:
Surround organs, tubes, eg.
stomach, urinary bladder, blood
vessels. Contract propels content
through organs (eg. expel urine).
Cardiac muscles:
Heart muscle makes your heart
pump blood.
Skeletal System
Facts about skeletal system
Do we have more bones when we are a baby or when we are all grown up?
 Baby has 305 bones and an adult has 206 bones. This is because as we grown some
of our bones join together to form one bone.
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The longest bone in our bodies is the femur (thigh bone).
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The smallest bone is the stirrup bone inside the ear.
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Each hand has 26 bones in it.
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our nose and ears are not made of bone; they are made of cartilage, a flexible
substance that is not as hard as bone.
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Differences between males and females: Males and females have slightly
different skeletons, including a different elbow angle. Males have slightly thicker and
longer legs and arms; females have a wider pelvis and a larger space within the
pelvis, through which babies travel when they are born.
Five main functions of the human skeleton
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Protect the vital organs we talked about last week
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2. Give us shape
3. Allow us to move because our muscles
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are attached to our bones
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4. Storage of nutrients such as calcium and silicon
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5. Formation of blood cells
Nervous System
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Thought
process,
regulation and
coordination of
many body
activities,
detection of
changes in
external and
internal
environments
Basic nerve structure
3 types of nerve structures
sensory
neurone
relay
neurone
motor
neurone
Endocrine System
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Main Function:
It releases hormones into
the blood to signal other
cells to behave in certain
ways. It is a slow but
widespread form of
communication.
Regulation and
coordination of many body
activities, including growth,
nutrient balance, and
reproduction
Endocrine System (Pituitary
Gland)
Function: It secretes nine hormones
that directly regulate many body
functions and controls functions of
other glands.
Disorders: Too much growth hormones
(GH) in early childhood can result in a
condition called gigantism. Too little
GH can result in Pituitary Dwarfism.
Endocrine (thyroid gland)
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Function: plays a major role in
regulation the body’s metabolism.
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Disorders: If the Thyroid Gland
produces too much Thyroxin, it can
cause a condition known as
Hyperthyroidism. If too little thyroxin
produces it is called Hypothyroidism.
Endocrine (pancreas)
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Function: The Insulin and Glycogen
in the Pancreas help to keep the level
of glucose in the blood stable.
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Disorders: When the Pancreas fails
to produce or properly use Insulin, it
can cause a condition known as
Diabetes Mellitus.
Endocrine (Adrenal Gland)
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Functions:
-The adrenal
glands release
Adrenaline in
the body that
helps prepare
for and deal
with stress.
-Also regulates
kidney function.
Endocrine (ovaries)
 Functions:
◦ Pair of reproductive organs found in
women that produce eggs.
◦ Also secrete estrogen and
progesterone, which control
ovulation and menstruation.
Endocrine (testes)

Functions:
◦ Pair of reproductive glands that
produces sperm.
◦ Also secrete Testosterone to give the
body its masculine characteristics.
Integumentary System
Functions of skin
Protection Cushions and
insulates and is waterproof
Protects from chemicals,
heat, cold, bacteria
Screens UV
Synthesizes vitamin D with UV
Regulates body heat
Prevents unnecessary water loss
Sensory reception (nerve
endings)
Dermis
Strong, flexible connective tissue: your “hide”
Cells: fibroblasts, macrophages, mast cells, WBCs
Fiber types: collagen, elastic, reticular
Rich supply of nerves and vessels
Critical role in temperature regulation (the
vessels)
 Two layers
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◦ Papillary – areolar connective tissue; includes dermal
papillae
◦ Reticular – “reticulum” (network) of collagen and
reticular fibers
Burns
First-degree
(epidermis only; redness)
Second-degree
(epidermis and dermis,
with blistering)
Third-degree
(full thickness, destroying
epidermis, dermis, often part
of hypodermis)
Skin Cancer
Nails
Hair
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Functions of hair
◦ Warmth – less in man than other mammals
◦ Sense light touch of the skin
◦ Protection - scalp
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Parts
◦ Root imbedded in skin
◦ Shaft projecting above skin surface
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Make up of hair – hard keratin
Hair cont…
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Types of hair
◦ Vellus: fine, short hairs
◦ Intermediate hairs
◦ Terminal: longer, courser hair
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Hair color
◦ Amount of melanin for black or brown; distinct form
of melanin for red
◦ White: decreased melanin and air bubbles in the
medulla
◦ Genetically determined though influenced by
hormones and environment
Reproductive System
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Procreation
Reproduction
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Primary sex organs (gonads) – testes in
males, ovaries in females
◦ Gonads produce sex cells called gametes and
secrete sex hormones
Accessory reproductive organs – ducts,
glands, and external genitalia
 Sex hormones – androgens (males), and
estrogens and progesterone (females)
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Digestive System
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Digestion and
absorption of
nutrients
Digestion Phases and structures
Phases
◦ Ingestion
◦ Movement
◦ Digestion
◦ Absorption
◦ Further digestion
Structures
•Mouth
•Oral Cavity
•Pharynx
•Esophagus
•Stomach
•Duedenum
•Jejenum
•IIleum
•Cecum
•Ascending
colon
•Transverse
colon
Mouth
Mechanical digestion
 Senses taste and
texture
 Salivary glands
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Esophagus
A tube that extends about
10 inches from the back of
the mouth, the pharynx, to
the top of the stomach
 Epiglottis: flap of tissue that
folds down over the
windpipe to keep food from
entering the respiratory
system
 Gastroesophageal sphincter:
section of esophagus next to
stomach that controls the
opening to the stomach
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Stomach
Holds up to four
cups of food
 Chyme: mixture of
gastric juices and
partially digested
food
 Pyloric sphincter:
controls the rate in
which chyme is
released into the
small intestine
 Stomach usually
empties in about 4
hours
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Stomach cont…
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Functions
◦ Mix food
◦ Reservoir
◦ Start digestion of
 Protein
 Nucleic acids
 Fats
◦ Activates some
enzymes
◦ Destroy some bacteria
◦ Makes intrinsic factor
– B 12 absorption
◦ Destroys some
bacteria
◦ Absorbs
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Alcohol
Water
Lipophilic acid
B 12
Small intestine
6 1/2 feet long
 Villa
 3 sections
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◦ Duodenum
◦ Jejunum
◦ Ileum
Villi in small intestine
Small intestine cont…
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Secretes digestive enzymes
◦ Peptidases
 Amino Di Tri◦ Sucrases
◦ Maltase
◦ Lactase
◦ Saccharidases
 Di Tri◦ Lipase
◦ Nucleases
•Requires pancreatic
enzymes & bile to
complete digestion
Large
intestine
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Regions
◦ Cecum – Appendix
◦ Colon
 Ascending
 Transverse
 Descending
◦ Rectum
◦ Anal canal
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Chyme becomes feces
Feces Formation
Chyme dehydrated to form feces
 Feces composition
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Water
Inorganic salts
Epithelial cells
Bacteria
Byproducts of digestion
Defecation
◦ Peristalsis pushes feces into rectum
◦ Rectal walls stretch
Accessory Organs
Play role in digestion even though
chyme does not move through
them
 Liver:
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◦ process and stores nutrients
◦ Makes cholesterol
◦ Uses lipids to make bile
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Gallbladder
◦ When food and fat are in the
duodenum, the small intestine send
signal for gallbladder to release bile
into duodenum
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Pancreas
◦ Produces and secretes most of the
enzymes that break down carbs,
protein, and fat in GI tract
◦ Secretes biocarbonate ions that
neutralizes HCL in chyme
Liver cont…
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Liver: Functions
◦ Makes bile
 Detergent – emulsifies fats
 Release promoted by:
 Vagus n.
 CCK
 Secretin
 Contains
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Water
Bile salts
Bile pigments
Electrolytes
Cholesterol
Lecithin
More Liver…yuck
◦ Detoxifies/removes
 Drugs
 Alcohol
◦ Stores
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Gycolgen
Vitamins (A, D, E, K)
Fe and other minerals
Cholesterol
Activates vitamin D
Fetal RBC production
Phagocytosis
Metabolizes absorbed food molecules
 Carbohydrates
 Proteins
 Lipids
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Dual blood supply
◦ Hepatic portal vein
 Direct input from small intestine
◦ Hepatic artery/vein
 Direct links to heart