Animal Responses Flashcards
What are the two parts of the nervous system
The central nervous system
The peripheral nervous system
What is the PNS
Includes all the neurones that lie outside the CNS
Two parts: Autonomic NS and Somatic NS
Features of the Autonomic NS
Part of the PNS
2 parts: Parasympathetic, Sympathetic NS
Self-governing, responsible for homeostatic mechanism
Non-myelinated
Ganglion at synapses
Features of the parasympathetic neurones
“Rest and Digest”
Ganglion near organ
V. Short postganglionic axon and V. Long preganglionic axon
ACh secreted by postganglionic neurone
What actions do the parasympathetic neurones cause
Dec heart rate
Constrict pupil
Dec ventilation
What are the features of the Sympathetic neurone system
Fight or flight
Ganglion just outside CNS
Pre ganglionic axon = V short
Post ganglionic axon = V long
Secretes noradrenaline
Effects of the sympathetic NS
Ic heart rate
Dilated pupils
Inc ventilation
Features of the Somatic Neurone system
Myelinated
Connections to effectors
One neurone
Transmit impulses to voluntary muscles
What is the knee jerk reflex
Spinal reflex
Only two neurones involved (sensory + motor)
No relay = cant be inhibited
Quicker
How does the knee jerk reaction occur
Pressure on tendon hamstring causes a stretch and pull on quadriceps
Receptors are sensitive to muscle being stretched suddenly
Impulse is sent along sensory neurone to spinal cord then to the motor neurone
What is the benefit of having a knee jerk reaction
helps with coordinated movement + balance
What are the main parts of the brain
Pituitary gland
Cerebrum
Hypothalamus
Cerebellum
Medulla Oblongata
What is the function of the cerebrum
all higher order processes
thinking
planning
language
memory
emotions
What is the function of the hypothalamus
Control of ANS and some endocrene glands
Maintains homeostasis
What is the function of the cerebellum
Muscle coordination and movement
what is the function of the medulla oblongata
Controls involuntary actions
The cardiovascular centre
Controls rate at which SAN fire
Recieves sensory inputs about O2/CO2 conc + bp
What is a reflex action
Response to a stimulus without a conscious decision
Faster and protective response
doesnt always need a relay neurone
What is the “fight or flight” response
coordinated responses to situations of perceived danger
stimulus -> sensory neurone -> hypothalamus
Hypothalamus causes pituitary gland to secret ACTH -> adrenal glands secrete steroid hormones
Hypothalamus activates sympathetic NS - adrenaline secreted
How is heart rate controlled
2 centres within medulla oblongata
- 1 inc heart rate by sending impulses through the sympathetic ns - transmitted by accelerator nerve
- 1 dec heart rate by sending impulses through the parasympathetic ns - transmitted by vagus nerve
How is heart rate monitored by chemoreceptors
detect changes in the level of chemical in the blood like CO2 - located in aorta, carotid artery and medulla
If CO2 level inc - pH dec bc of carbonic acid formed
Dec in blood pH = response to inc heart rate
How is heart rate monitored by baroreceptors
It monitors changes in blood pressure
How is heart rate controlled
There are 2 centres within the medulla oblongata linked to the SAN
One centre inc heart rate by sending impulses through the sympathetic NS - transmitted by accelerator nerve
One centre dec heart rate by sending impulses through the parasympathetic NS - transmitted by vagus nerve
When is the student’s t-test (paired) used
To compare the mean between two groups
What are the three types of muscles
Skeletal
Smooth
Cardiac
