lecture 1: homeostasis and organ systems Flashcards
what is the circulatory system
cardiovascular
lymphatic
how many organ systems regulate blood pressure
4
describe the organ systems that regulate blood pressure
circulatory - pressure and blood against vessels
nervous - dilating vessels, sends signals
musculoskeletal - acts as pump for blood
excretory - controls fluids (pressure)
name the organ systems that regulate blood pressure
circulatory - cardiovascular and lymphatic
nervous
musculoskeletal
excretory
what is anatomy
study of structure of body parts and their relationship to one another
what is physiology
study of function of body parts and how they work together to carry out life sustaining activities
state order of structural organization
atoms
molecule
organelle
cells
tissues
organs
organ systems
definition of homeostasis
maintenance of relatively stable internal conditions despite continuous changes in environment
describe homeostasis
organ systems collaborate to regulate variables, things that can change, within body - goal = maintain homeostasis
name variables maintained by homeostasis
37 degree body temp
blood pressure
hormone levels
cholesterol
blood sugar
heart rate (resting)
name components of homeostasis
set point
stimulus
control center
response (–> back to set point)
how many mechanisms to maintain homeostasis
2
name the 2 mechanisms to maintain homeostasis
negative feedback
positive feedback
describe negative feedback
counteracting change
reduces or shuts off original stimulus
keeps variables in narrow range
describe positive feedback
exaggerates stimulus - moves further away
enhances original stimulus
continues till end point
which mechanism is most common and why
negative feedback
want to maintain homeostasis
what type of feedback is body temp regulation
negative feedback
describe receptor body temp regulation
temperature sensitive cells in skin and brain (hypothalamus)
senses temp of cerebral spinal fluid
describe control center body temp regulation
brain - hypothalamus
name effectors body temp regulation
sweat glands
blood vessels
skeletal muscles
ALL INVOLUNTARY
describe sweat glands
hot
turned on by nervous system
helps you cool off
describe blood vessels (effector of body temp regulation)
hot - dilate, make skin red, more blood, exchange heat with environment
cold - turns skin white first, blood flow diverted to core of body and vital organs, constricts blood vessels in extremities
describe skeletal muscles
cold
shivering
skeletal muscles contracting
help warm you up
what is a fever and why does body cause it (+ shiver)
negative feedback
immune response to counteract illness
hypothalamus changes set point (to combat) - higher so temp rises to get there, but doesnt reach exact set point so you shiver (39 degrees, but wants 40)
THEN cold sweat bc set point goes back to lower, so sweats to get heat lower
what type of feedback is blood sugar
negative feedback
name receptor and control centre for blood sugar
pancreas
describe high blood sugar
insulin
cells take up glucose from blood
glycogen is formed - liver and muscle
describe low blood sugar
glucagon
glycogen is broken down - liver cells
glucose released into blood
name the 3 things (organs/tissues kinda) which have to do with blood sugar
liver
skeletal muscles
adipose
what type of feedback is blood clotting
positive feeback
describe blood clotting
amplified chain reaction
platelets stick to damaged region of blood vessel
they release chemical that recruits more platelets - all pile up until end point (stop bleeding)
what is the set point for blood clotting
no blood clot
but then blood clot forms be injury and leads to positive feedback
describe blood clotting cycle
break or tear in vessel wall
positive feedback cycle
platelets adhere to site and chemicals released attracts more
platelet plug forms - end of cycle
what is bruising
internal bleeding
even if not like a cut gushing blood it still bleeds
what type of feedback is childbirth
positive
describe childbirth
pressure of babys head against cervix
stimulates release of oxytocin
causes uterine contractions (then causes baby head to put more pressure, restarts cycle)
keeps getting stronger (more pressure)
what is the endpoint of childbirth
contractions end when childbirth is complete
