Homeostatis and Hypothalamus 2

Question 1

What are organ reflexes loops?

Answer 1

Internal organs have intrinsic control mechanisms. Can operate at a baseline level on their own BUT organ reflexes can’t adjust to changes.

Question 2

What is an example of organ reflexes loops?

Answer 2

Heart has built in “pacemakers” to regulate heartbeat. Heart will pump on its own at about 110 beats per minute. Heart automatically pumps harder when filled with larger amount of blood. BUT the automatic pumping would fail to adapt if person stood up or started to run.
Goosebumps.

Question 3

What is local reflex loops?

Answer 3

Oragans send/receive info to spinal cord creating reflex loops. Oragan and spinal cord can adapt organ functioning to local needs.

Question 4

Organs of homeostatic organization : Respiration

Answer 4

Oxygen is required ti fuel our metabolism by burning glucose. The waste product of cellular respiration is carbon dioxide.

Question 5

What do lungs do?

Answer 5

They regulate intake alf oxygen and expelling of carbon dioxide.

Question 6

Organs of homeostatic organization : Blood Glucose

Answer 6

Must regulate levels of glucose available to the body.

Question 7

What does the pancreas do?

Answer 7

It detects glucose levels. Releases insulin when glucose levels are too high (extra glucose get stored). Releases glucagon when glucose levels are too low (to free up stored glucose)

Question 8

What does the drug ozempic do?

Answer 8

It is used to lose weight and was designed to regulate blood sugar levels.

Question 9

Organs of homeostatic organization : Water Regulation

Answer 9

Proper hydration is needed to transport material throughout the body.

Question 10

What do the kidneys do?

Answer 10

Monitor and regulate levels of water in the blood. When water levels are low, kidney reduces amount of water in urine to keep the blood water levels higher.

Question 11

Organs of homeostatic organization : Thermoregulation

Answer 11

Must regulate body temperature for optimal metabolism. The biochemical reactions like enzyme activity impact by temperature.

Question 12

What happens when a person gets too hot?

Answer 12

Sweat glands are activated to cool down the body.

Question 13

What happens when a person gets too cold?

Answer 13

Muscles shiver to raise body temperature. Getting goosebumps is an example of organ reflex.

Question 14

What is the pilomotor reflex?

Answer 14

tiny muscles attached to hair follicles contract in response to the cold. Hair standing up may trap warm air around the body (evolutionary leftover)

Question 15

What other time can pilomotor reflex be triggered?

Answer 15

can be triggered by activation of sympathetic nervous system.

Question 16

Where does the spinal cord run through?

Answer 16

Runs through a space at the back of the backbone called the vertebral foramen.

Question 17

Where does the spinal cord end?

Answer 17

It ends at the lumbar area.

Question 18

Where is the grey matter and white matter located in the spinal cord?

Answer 18

The center of the spinal cord is filled with grey matter (cell bodies) and surrounded by white matter (axons, nerves).

Question 19

The somatic Nervous System.

Answer 19

Conscious and Voluntary
“Skeletal Nervous System”
Sensory and Motor neurons
Motor neuron directly connects to muscle

Question 20

What do the sensory and motor neurons do?

Answer 20

They send info to CNS (spinal cord and brain)
Motor neurons from CNS directly connect to a specific set of muscle fibers.
Allows very precise control
Axons are well myelinated. Conducts signals rapidly.

Question 21

The Autonomic Nervous System.

Answer 21

Unconscious and Involuntary.
Sympathetic and Parasympathetic.
Also has sensory and motor neurons
Sensory info from internal organs sent to brainstem. Remains unconscious. Axons are not well myelinated. Conducts signals slowly.
Motor neuron connects to ganglia.

Question 22

What does the Ganglia do?

Answer 22

Ganglia “relays” signal to the muscle.

Question 23

What does the autonomic nervous system innervate?

Answer 23

Cardiac muscles, smooth muscle, and glands. Internal organs often contain “smooth muscle” such as stomach, intestines, badder, blood vessels, kidneys

Question 24

What does the autonomic nervous system regulate?

Answer 24

The internal organs and
The metabolic functions and physiology.
Heart rate, respiration, blood pressure, digestion, urination, glucose storage/use, body temperature.

Question 25

What are the main divisions of the ANS?

Answer 25

Sympathetic
Parasympathetic
Entric Nervous System (“food and feces”) -semi autonomous system in digestion.

Question 26

Why does panic make you pee?

Answer 26

Sympathetic nervous system relaxes bladder to hold more pee.
Parasympathetic : constricts bladder to release pee.

Question 27

When can both the sympaethic and parasympathetic get activated?

Answer 27

When there is a disorganized fear response. They are two speperate systems that mostly act to counter each other. A large symapathetic response prepares a large parasympathetic counter response.

Question 28

Components of the ANS?

Answer 28

Descending nerve fibers : from hypothalamus and brain stem. Descend through the intermediolateral cell column of spinal cord.
Preganglionic nerve fibers: extend from spinal cord to different autonomic ganglia.
Ganglia: relays signals back and forth between internal organs and spina cord. Densely packed and interconnected neurons allow ganglia to act as mini brains. Involved in “local reflex loop”
Postganglionic nerve fibers: travel from ganglia to their target organs.
Neuroeffector junctions: place where the postganglionic nerves alter activity of the organ. similar to synapse.

Question 29

What can the sympathetic nervous system also be called?

Answer 29

Thoracolumbar division

Question 30

What can the parasympathtic division also be called?

Answer 30

Carniosocral division.

Question 31

The Sympathetic Division

Answer 31

The nerves are projected from the middle of the spine (thoracic region)
Sympathetic ganglia are connected in a “sympathetic chain”
The chain is located next to spine

Question 32

The preganglionic nerves in the sympathtic division are..?

Answer 32

they are short and release acetylcholine to activate chlingerice(nictinic) receptors.

Question 33

The postganglionic nerves in the sympathetic division are..?

Answer 33

they are long and release norepinephrine to activate adrenergic receptors.
They have many branches and affect many organs.

Question 34

Parasympathetic Division

Answer 34

Parasympathetic ganglia are not connected. They are located in the internal organs.

Question 35

The preganglionic nerves in the parasympathtic division are..?

Answer 35

they are long and release acetylcholine.

Question 36

The postganglionic nerves in the parasympathetic division are..?

Answer 36

they are short and release acetycholine.
They have few branches and effects specific organs.