Animal Responses Flashcards
The nervous system is split into the CNS & PNS - what’s the difference
CNS = brain & spinal cord
PNS = rest of neurons that connect CNS-body
The PNS is composed of sensory + motor neurons & sensory receptors outside of the CNS
- they connect & ensure rapid communication between sensory receptors, the CNS & effectors
Divisions of the PNS
What’s the sensory nervous system
- division of PNS
- sensory fibres entering CNS (dendrons of sensory neurons)
- sensory neurones enter the spinal cord through the dorsal root
- motor neurones leave the spinal cord through the ventral root
Whats the motor nervous system & its two divisions
It’s a division of the PNS
It conducts action potentials from the CNS to effectors
Breaks into the somatic nervous system & autonomic nervous system
Somatic versus Autonomic nervous system
What 2 divisions does the autonomic nervous system break down into?
Sympathetic system (fight or flight)
Parasympathetic system (rest & digest)
Sympathetic vs Parasympathetic system
What is the central nervous systems functionm
Made up of the brain & spinal cord
Function: transmit messages to and from the brain
Controls spinal flexes
Function & features of the spinal cord
- many relay neurons
- central grey matter
- many myelinated neurones
- outer white matter
-> rapid transmission of action potentials up and down the spinal cord
+ protected by the veterbrae column
between each vertebrae, peripheral nervous enter & leave the spinal cord, carrying action potentials to form the rest of the body
Structure of the brain
Function & structure of the cerebrum
Function!
Deals with higher functions e.g. conscious thought & actions, emotional responses, speech, thinking, problem solving & memory, vision & hearing
Structure
- divided into 2 cerebral hemispheres
- connected via corpus callosum
- right hemisphere controls left side & vice versa
- largest part of the brea
- has grey & white matter
Function & structure of cerebellum
Function:
Co-ordinates balance & fine control of movement
works subconsciously / involuntarily
Structure:
- below cerebrum
- has complex nervous pathways, strengthened by practice
Medulla oblongata function
- Controls physiological processes & Co-ordinates automatic stuff
(Via negative feedback) - controls non-skeletal muscles e.g. cardiac / involuntary smooth
3 centres: cardiac, vasomotor & respiratory - to regulate vital processes
What do the 3 centres of the medulla do (cardiac, vasomotor, respiratory)
Cardiac - controls heart rate
Vasomotor - controls contraction of smooth muscles in arteriole walls - and therefore blood pressure & circulation
Respiratory - controls breathing rate & depth
Where’s the medulla found
@ the base of the brain, where the brain joins the spinal cord
Hypothalamus functions & features
- Co-ordinates homeostatic responses by negative feedback to maintain a constant internal environment
- e.g. Thermoregulation, osmoregulation
- monitors temperature & water potential of blood flowing through
- has sensory receptors
- can release hormones / stimulate pituitary gland
Pituitary gland function & structure
Produces range of hormones
Acts in conjunction with the hypothalamus
Divided into 2 lobes - anterior & posterior
Found @ the base of the brain
Endocrine gland
Below hypothalamus (attached under it)
What does the anterior lobe of the pituitary gland do
Secrete many hormones which control a no. of physiological processes, e.g. stress, growth, respiration
What does the posterior lobe do:
Stores & releases hormones made by hypothalamus
What are reflex actions
Responses to stimuli which don’t involve any processing in the brain to co-ordinate movement
What’s the reflex pathway
Sensory neurone detects stimuli -> relay neurone -> motor neurone -> this conducts action potential to the effector -> appropriate response
Pathway as short as possible so the reflex is a rapid response
What is the value of reflex actions
The 3 types of reflex actions we have to know
- Knee jerk
- Blinking
- Corneal
Details about the knee jerk reflex
