Lecture 22. Nervous Regulation of Physiological Function Flashcards
What does homeostasis in animals rely heavily on ?
Negative feedback
What is negative feedback ?
Helps to return a variable to a normal range
What are some things that rely on negative feedback ?
Temperature regulation, blood glucose regulation
What is the function of positive feedback ?
Amplifies a stimulus in animals in a small number of functions
What may you see positive feedback in ?
Childbirth, blood clotting, electrical impulses in nerves
What is feedforward ?
Anticipatory responses to expected change
What are some examples of feedforward ?
Increased heart rate in anticipation of exercise, increased secretion of insulin before food is digested to yield glucose, stimulation of gastric secretions due to thought/smell of food
What does external environment contain ?
- Temperature
- 02, CO2, water, food
- Light
- Noxious stimuli/predators
What does the internal environment contain ?
- Composition of body fluids
- Temperature
- Metabolites
- Blood pressure
- 02 and CO2 in tissues
What are the fluid compartments of the human body ?
- Total body water
- Intracellular fluid
- Extracellular fluid
- Plasma
- Interstitial fluid
What is the volume of the total body water ?
42 L
What is the volume of intracellular fluid ?
28L
What is the volume of extracellular fluid ?
14L
What is the volume of plasma ?
3L
What is the volume of interstitial fluid ?
11L
What is physiological function regulated by ?
- Nervous system
2. Endocrine system
What is the nervous system ?
A network of specialised cells (neurons) that transmit signals along dedicated pathways
What are some features of the nervous system ?
- Hard wired
- Fast acting
- Electrical and chemical signaling
- Local cellular responses
- Rapid response by target cell
What is the function of endocrine system >
Chemical signaling by hormones
What are some features of endocrine system ?
- Hormones transported in blood
- Slower acting
- Chemical signaling often involves changes in gene expression
- Slower and often long lasting responses of target cells
What are four examples of interaction an cooperation?
- Some nerves innervate endocrine glands, eg. adrenal glands
- Hypothalamus and pituitary are brain regions that regulate endocrine function
- Blood pressure is regulated by nerves acting on the heart and blood vessels and by hormones acting on kidneys to regulate blood volume
- Glial cells in the nervous system play an important role in nervous function
What derives from efferent neurons ?
- Autonomic nervous system
2. Motor system
What derives from autonomic nervous system ?
- Sympathetic division
- Parasympathetic division
- Enteric nervous system
What does the autonomic nervous system control ?
Control of smooth muscles, cardiac muscles, glands
What is found in the forebrain ?
- Cerebrum
- Thalamus
- Hypothalamus
What is found in the hindbrain ?
- Pons
- Medulla oblongata
- Cerebellum
What is the brainstem ?
Consists of the midbrain, the pons and the medulla oblongata
What is the function of the midbrain ?
Receives and integrates sensory information and sends it to specific regions of the brain
What do the pons and medulla do ?
Transfer information between the peripheral nervous system and the midbrain and forebrain
What is the function of the medulla ?
Controls several basic functions such as breathing, heart and blood vessel activity, swallowing, vomiting and digestion
What is the function of the cerebellum ?
Coordinates movement and balance and helps in learning and remembering motor skills