UNIT 1 Flashcards
What are the main body systems?
- Integumentary
- muscular
- skeletal
- nervous
- digestive
- reproductive
- cardiovascular
- lymphatic
- endocrine
- respiration
- urinary
What are the 4 main types of tissue and what do they do?
- Epithelial: covers the of the body, lines body cavities and cavities of organs, and forms the secretory portions of glands
- Connective: binds organs together and provides protection and support for organs and the entire body
- Nervous: coordinates body functions via the transmission of nerve impulses
- Muscle: contracts to enable movement of the body and body parts
What is the function and location of epithelial tissue?
Location: Body cavities and ducts, blood vessels, bladder, GI tract, skin, respiratory passage.
Function: protects, covers and lines, provides sensory input, manufacture secretion and excretion
What is the function of nervous tissue?
Coordinates body function through nerve impulses
Body cavities
Dorsal
Ventral
Thoracic
Abdominal
Thoracic cavity membranes and what they line
Visceral pleura: lines thoracic organs
Parietal Pleura: lines thoracic wall
Mediastinum: separates 2 halves of the chest down a median plane
Abdominal cavity membrane
Visceral Peritoneum: lines abdominal organs
Parietal Peritoneum: lines abdominal wall
Body membranes and cavities
- Between these membrane linings is a ‘potential space’ lubricated by pleural or peritoneal fluid
- This fluid is secreted by the membranes lining the body (pleura and peritoneum)
- Serves to reduce friction as lungs move during
respiration and organs move within the abdomen. - Inflammation (pleuritis/pleurisy or peritonitis) is very painful.
- Note that another term used to generally refer to this type of body fluid (regardless of where it is found) is serous fluid.
- The heart is also enclosed in its own membrane, derived from the mediastinum.
o This is called the pericardium
o forms a layer over the heart as well as a loosely formed sac surrounding the heart
o contains serous fluid to reduce friction
Levels of organization
Cells
Tissues
Organs
Systems
Organism
Cells
- Cell is made up of organic molecules and water molecules (avg 20%:80%)
- Cells are highly specialized, depending on their function in the body, but all cells have 3 basic parts:
o cell membrane_(plasma membrane or
plasmalemma)
o nucleus
o cytoplasm
Tissue level of organization
Made up of cells of the same type
Epithelial tissue
composed entirely of cells and functions to
cover and protect the surface of the body. Body surfaces include skin, as well as the lining of the GIT, respiratory
system, cardiovascular system, reproductive system, and bladder.
Some groups of epithelial cells have specialized to form glands, such as sweat glands, salivary glands, and mammary glands.
Connective tissue
‘connects body cells’ to provide support and structure to the soft cells. Composed of cells and intercellular substances such as fibers for added strength. Can range from fat (adipose tissue) to cartilage and bone.
Muscular tissue
move the body. Includes striated and smooth muscle. Operates under both conscious (i.e. skeletal muscle) and
unconscious (i.e. cardiac and smooth muscle – GIT, urinary bladder) control.
Nervous tissue
transmits information, including sensory, around the body and helps to control functions and movement within the body.
Organ level of organization
- An organ is made up of a variety of tissues that work together
- Example: stomach – contains all 4 basic tissue types
- Some occur in pairs (kidneys, eyes), others singly (brain, heart)
System level of organization
- System is made up of several organs that perform related functions
- Probably the most logical approach to understanding anatomy and physiology
Integumentary system
- Integumentary
o Includes skin and the ‘epidermal derivatives’ such
as nails, glands, and hair.
o Functions include sensation, protection,
immunity, excretion, blood reservoir, vitamin D synthesis,
and temperature regulation
Skeletal system
o Includes the axial skeleton (skull, vertebral column, and
ribs) and appendicular skeleton (pectoral and pelvic
girdles, front and hind extremities)
o Involves bones, ligaments, and associated cartilages.
o Functions in support, protection, movement, blood cell production, and mineral storage
Muscular system
o Skeletal muscle moves the body through the environment
o Cardiac and visceral move parts internally
▪ Note that there is overlap with cardiovascular
system and others
o Functions in movement and heat production
Nervous system
o Includes brain, spinal cord, nerves, ganglia, sensory receptors, and special senses organs
o Functions in regulation and coordination of body activities, detection of changes both internal and external, consciousness, memory and learning
Endocrine system
o Includes hormone – producing glands such as
hypothalamus, anterior & posterior pituitary, thyroid, parathyroid, adrenal cortex & medulla, kidneys, pancreas, stomach, duodenum, testes, ovaries, placenta, thymus, pineal gland
o Functions to regulate and coordinates body activities through hormone secretion
Cardiovascular system
o Includes heart, blood vessels (arteries, veins, and capillaries) and blood
o Functions to transport food, wastes, gases, and hormones to and from body cells
Lymphatic system
o Includes bone, lymph vessels & nodes, spleen, thymus, and lymphoid tissue
o Functions in defense against infection, return of
extracellular fluid to blood, and formation and differentiation of WBC’s
Respiratory sytem
o Includes nose, pharynx, larynx, bronchi, bronchioles, and lungs
o Functions in the exchange of carbon dioxide and
oxygen between air and blood in the lungs and the
regulation of hydrogen ions
Digestive system
o Includes mouth, pharynx, esophagus, stomach, intestines,
salivary glands, pancreas, liver, and gall bladder
o Functions in digestion and absorption of nutrients, salts, and water
Urinary system
o Includes kidneys, ureters, urinary bladder, and urethra
o Functions in regulation of excretion of organic
wastes, salts, and water to control plasma composition
and volume
Reproductive system
o Includes male (testes, penis, associated ducts and glands)
and female (ovaries, uterine tubes, uterus, vagina,
mammary glands) organs
o Functions for male involve production and transfer of
sperm to female; functions for female include egg
production and an environment in which the embryo can
develop.
Organism level of organization
- Contains all systems working together.
- Requires communication and a precise balance of all systems to maintain a state of health (homeostasis)
o Immune system protects body
o Temperature regulation
Homeostasis
Homeostasis is maintenance of a relatively stable internal environment, also referred to as a ‘dynamic equilibrium’ within the body (i.e. a changing or active balance) * Involves sensors, control centers and responders
* Despite constant fluctuations in the external environment and substances entering and leaving the body a constant internal environment is maintained
* Examples include the control of body temperature and acid-base balance
* Maintenance of a healthy state requires proper functioning of all levels of organization and preserving homeostasis
Epithelial tissue
Epithelial tissue is composed of sheets of cells that cover and line other tissues. It lines all of the body cavities and ducts, all blood vessels, the bladder and the gastrointestinal tract, as well as the skin and respiratory passages.
Functions of epithelial tissue
- Protects, covers and line
- Filters biochemical substances
- Absorbs nutrients
- Provides sensory input
- Manufactures secretions(mucin, hormones, enzymes)
- Manufactures excretions (sweat, milk)
* Tends to be classified as
1) covering and lining epithelium
2) glandular epithelium
General chracterisitcs of epithelial tissue
- They are polar
- Attached by later complex junctions
- Avascular
- Variably innervated
- Regenerate
- They have a “right side up” and are polar. They have an Apical Surface and a Basal surface.
The apical surface is the surface of the cell which is:
* Exposed to a body cavity
* Lining an internal organ, or facing the lumen
* Exposed to the exterior
The basal surface is the surface of the cell which is attached to a basement membrane, or faces underlying tissue
❖ Epithelial cells have sides or lateral surfaces that attach to neighboring cells by junctional complex. - Epithelial cells are avascular (no blood vessels) and rely on underlying connective tissue to supply needed nutrients and waste exchange
- Some epithelia lack nerves, others are innervated and provide valuable sensory information to the body
- Epithelial tissues regenerate rapidly by mitotic division of cells – large numbers are being destroyed and replaced daily.
Cellular attachments
Cells are held together in a number of ways
* Sides of cells fit together with an interlocking pattern
* Have matrix-filled channels running between cells
* Membranes are joined with junctional complexes that provide strength
Tight junctions
form a fluid-tight seal between cells
o The outer layers of plasma membrane between two cells are fused
o Tends to be found in a strip around the circumference of the cell like a belt
o Prevents penetration of substances and leakage
o Very important in the urinary bladder and digestive tract (keeps toxins and digestive enzymes from the bloodstream)
Desmosomes
or Anchoring junctions: fasten cells to one another or to extracellular materials like the basement membrane
o Made up of a plaque of interlocking filaments
o Some of the filaments penetrate from the plaque into the cytoplasm of (like an anchor) to stabilize the bond
o Important in areas which have lots of stretching/tension, like in the skin, heart, and uterus
Gap junctions
Gap (or Communicating) junctions: form fluid-filled tunnels between cells. Connexons: tubular channel proteins link adjoining cells
o Cytoplasm is joined by this ‘tunnel’ and allow exchange of nutrients and ions
o Most common in the intestinal epithelial cells, heart, and smooth muscle.
o Help coordinate the actions of cells by their ability to transport ion change signals quickly. Also common in cardiac and smooth muscle for similar reasons.
Basement membrane
attaches the epithelium to the underlying connective tissue. Function to resist rubbing and erosion. Not a true membrane, so often referred to as basement (or basal) lamina.
It is acellular, consisting of a colloidal (gelatinous and viscous fluid) complex of protein, polysaccharide, and reticular fibers. It is also important to help control the movement of nutrients and waste from underlying tissue to the epithelium and reverse. Oxygen and nutrients and epithelial cell wastes diffuse across the basement membrane from and into the blood vessels in the connective tissue below.
Simple squamous epithelium
- Description: single layer of flat, smooth, scale-like cells with irregular outlines and central nucleus. May resemble tiles of a mosaic from surface view
Flat and smooth - Function: reduce friction, filtration, nutrient exchange by diffusion, * Not strong, so needs to be supported
- Location. Lines:
o Air sacs of lungs (assist O2 and CO2 exchange)
o Inner lining of blood vessels and heart (called endothelium
in the C-V system),
o Peritoneal, pleura and pericardial cavities
▪ Called mesothelium
▪ Or serous membranes as they secrete a watery
lubricating fluid