UNIT TEST 1: Homeostasis And Body Cavities (Ch.1, Pt.3) Flashcards
What’s “HOMEOSTASIS”?
The body’s ability to maintain STABLE INTERNAL CONDITIONS, regardless of the changes in the outside world.
What are the 3 components of the HOMEOSTATIC CONTROL MECHANISM?
RECEPTOR
EFFECTOR
CONTROL CENTER
Define the “RECEPTOR” (component of the HOMEOSTATIC CONTROL MECHANISM). Give ex.
Sensor that monitors environment & sends info to control center.
Ex. Nerves receptors on my skin (temp.)
Define the “CONTROL CENTER” (component of the HOMEOSTATIC CONTROL MECHANISM).
Where are they located?
- Receives info from RECEPTOR to send signals to the EFFECTOR.
- Regulates the “set point”(normal point at homeostasis)
Location: spinal cord, brain, endocrine gland (sometimes).
Define the “EFFECTOR” (component of the HOMEOSTATIC CONTROL MECHANISM).
Responds to signals from the CONTROL CENTER and changes body conditions:
-By returning conditions to normal (negative feedback).
OR
-By increasing the change (positive feedback).
How are the 2 different changes of body condition caused by the “effector” (last component of the homeostatic mechanism) called?
Negative feedback
Positive feedeback
Describe “NEGATIVE FEEDBACK”. Give ex.
A mechanism that brings body conditions back to normal when there has been a change. (Most common one).
Ex.
- When you exercise, your body overheat, homeostatic mechanisms will work to bring the temp of your body back to 96 F (36 C).
- When BLOOD GLUCOSE increases or decreases form the set point, pancreas releases insulin into the bloodstream or a hormone decreases it until normal. Once the ideal is reached, it shuts down. Pancreas serves as the sensor, control center, and effector.
ANALOGY: set point is 72 F, if temp drops, the thermostat send a signal to the furnace and this one returns temp back to 72, the furnace turns off once the ideal temp is reached.
Describe “POSITIVE FEEDBACK”. Give ex.
(More rare) A mechanism triggered by a small change, that causes to create a greater and greater change until a climax is reached. (It doesn’t get things back to normal, it fixes things).
Ex.
-When a wall vessel is damaged (small change), it trigger many reactions, palates come together and form a blood clot to cover the damage and then the process shuts down. Climax: creation of a clot (stopped when the hole was all covered).
- childbirth: when the baby’s head pushes against the cervix of the uterus, it triggers neural impulses that signals the brain to release a hormones called oxytocin that causes greater and greater contractions until the baby is released, process then shuts down. Climax: the baby released.
Give one example of RECEPTOR, CONTROL CENTER & EFFECTOR
- Receptor: thermometer (temp. SENSOR)
- Control center: thermostat (send signal to the furnace).
- Furnace: effector: responds casing a change.
How many types of body MEMBRANES are there? Mention them all.
Four
Meninges
Mucous
Serous
Synovial
Whats the “MUCOUS” MEMBRANE?
Whats it’s function?
Where are they found?
Soft TISSUE that covers the body’s canals and organs (digestive, respiratory and reproductive).
- To produce MUCUS (slimy, sticky secretion that protects the tissues below & traps dust/particles that are swallowed or inhaled.
- Found in the MOUTH/ANUS (GI TRACT); VAGINA; RESPIRATORY PASSAGEWAYS.
(It opens to the outside)
Whats the “SEROUS” MEMBRANE?
Whats it’s function, and where are they found?
How many layers is it made of?(mention them).
What are the different names used according to where its located?
TISSUE that covers an organ (it has two layers with a cavity in between). Imagine pressing down a balloon.
- To produce serous fluid for lubrication to reduce friction.
- Two layers:
PARIETAL (OUTWARD of the organ).
VISCERAL (INWARD of the organ) at the surfacace - PERICARDIUM (HEART)
- PLEURAL (LUNGS)
- PERITONEUM (ABDOMINAL CAVITY)
(Doesn’t open to the outside)
Whats the “MENINGES” MEMBRANE?
Whats it’s function, and where are they found?
How many layers is it made of?(mention them).
Covering TISSUE that surrounds the BRAIN & SPINAL CHORD.
-Act like a cushion to protect from injury and infections.
- Three layers:
DURA MATER (outermost) it has some kind of hairs
ARACHNOID MATER (middle one)
PIA MATER (innermost)
(Doesn’t open to the outside)
Whats the “SYNOVIAL” MEMBRANE?
Whats it’s function, and where are they found?
TISSUE that covers/line SYNOVIAL JOINTS. (Ex. Elbow, knee, etc)
- To lubricate joints to allow them to move freely by secreting synovial fluid allowing it
(Doesn’t open to the outside)
When it comes to body membranes; what does it mean that a membrane does/does not open to the outside? Give ex.
IT DOES NOT OPEN TO THE OUTSIDE: doesn’t come into contact with the external world/outside the body. SYNOVIAL, SEROUS, & MENINGES membranes.
IT OPENS TO THE OUTSIDE:
meaning that it can come into direct contact with the external environment/outside the body. MUCOUS membrane. Ex. Nasal or oral mucosa.
