regulation (maintain homeostasis)
-works by using chemicals formed by special cells to regulate processes throughout the body.
-responses are slower, but last longer.
the endocrine system works very closely with...
the circulatory system
the chemicals that are involved in regulation in the the endocrine system.
-released directly into the bloodstream
hormones travel in the blood until they reach this. which contains compatible receptors on its surface
are chemically specific , they can only bind to hormones meant for that receptor (same shape, lock and key)
after a hormone binds to a receptor molecule, this occurs. can occur in the target cell
responses of the endocrine system regulate:
growth, blood pressure, immune responses, the rate of metabolism, muscle contraction, responses to stress, digestion, the development and function of the reproductive system
what hormones are produced in and released from
release secretions through tubes or ducts.
-examples: sweat from glands, digestive enzymes from pancreas
release secretions directly into the bloodstream
a gland that controls secretions of other glands such as the pituitary
regulates the function of other glands
gland that regulates metabolism
gland which regulates blood calcium levels
controls T-cell production
gland which regulates responses to stress
regulates secondary sex characteristics of females and egg production
regulates secondary sex characteristics of males and sperm production
what the endocrine system uses to maintain homeostasis
uses this for body temp. regulation, regulation of water & blood sugar regulation
- cause-effect mechanism
a change detected in the body causes an action in the appropriate area, which will return the body to its original condition
-example "A" causes a change in "B" which than causes a change back in "A"
the body doesn't produce enough insulin (type 1) or the body doesn't respond to the insulin (type 2) and blood glucose remains high
the body doesn't produce enough glucagon and the blood glucose remains low
extremely small stature due to a deficiency of human growth
extremely large stature due to a surplus of human growth hormone
it function is to maintain homeostasis by controlling and coordinating functions throughout the body and responding to the internal and external stimuli
a detectable change in the internal or external environment
are cells of the nervous system
-transmit electrical impulses throughout the body
contains the nucleus and most of the cytoplasm of the cell. the site of metabolic activity
branched extensions off of the cell body which carry impulses from other neurons to the cell body
long fiber that carries the impulses away from the cell body to other neurons
-covered in a myelin sheet for insulation
bundles of neurons branching from the central nervous system to all parts of the body
-long axons of neurons bundle together
a type of neuron , carries impulses from the sense organs to the central nervous system
a type of neuron, carries impulses from the central nervous system to muscles and glands
a type of neuron, located in the central nervous system, carries impulses between sensory and motor neurons
nerve impulses are formed when...
there is a change in change of the cell membrane of a neuron
caused by a flow of ions (potassium and sodium)
once an impulse occurs...
neurons stimulate other neurons in with they are connected
the minimum level needed to activate s neuron
at what impulses travel from neuron to neuron is
at the end of each neuron an impulse reaches this
what impulses travel across the synapse as
chemicals used by neurons to transmit impulses across a synapse to other neurons
the nervous system is divided into these to major divisions...
central nervous system, peripheral nervous system
central nervous system
control center of the body which processes, analyses and relays info.
peripheral nervous system
includes the nerves which branch from the CNS
brain and spinal cord
-protected by 3 layers of connective tissue called meninges.
-space between the protective layers contains cerebra spinal fluid (CSF):
fluid acts as an absorber. allows exchange of nutrients and waste products between the blood and nervous tissue.
separated into 3 parts: cerebrum, cerebellum, brain steam.
-each part contains a pacific function of the body
controls voluntary or conscious activities of the body including intelligence and learning.
brain divided into this.
-left controls the right side of the body, while right controls the left side of the body.
hemispheres is divided into this.
-frontal, occipital, parietal and temporal
receives messages from the sensory organs and relays the info to the cerebrum which causes a response.
recognizes hunger, thirst, fatigue, anger and the body temp.
controls coordination and balance
-located at the bottom back of the skull
connects the brain and spinal cord.
- controls involuntary body functions including blood pressure, heart rate, breathing and swallowing
-contains the pons and the medulla oblongata
main communication link between the brain and the rest of the body
-reflexes are produced directly here
the bones that protect the spinal cord
a quick automatic response to a stimulus
-allows for an immediate response to danger
peripheral nervous system
all nerves extending off of the brain and spinal cord
-sensory and motor function
transmits impulses from the sense organs to the central nervous system
transmits impulses from the central nervous system to the muscles or glands.
- two divisions: somatic and automatic
- controls activities that are under conscious control
-movement of skeletal muscles
- controls activities not under conscious control
-heartbeat, movement of smooth muscles in organs and blood vessels.
-further divided: sympathetic and parasympathetic