16) Animal Responses Flashcards
What is the 2 main structural systems
Central nervous system
Peripheral nervous system
How is the peripheral nervous system structured
Peripheral nervous system
l
Somatic nervous system + Autonomic nervous system
l
Sympathetic + parasympathetic nervous system
What is the CNS / PNS
CNS - Brain and spinal chord
PNS - neurones that connect CNS to body
What is the somatic nervous system
Controls conscious activities
eg , running
What is the autonomic nervous system
control unconscious activites
eg , digestion
What is the sympathetic nervous system
Get body ready for action
‘Fight or flight @
Release noradrenaline , adrenaline
What is the parasympathetic nervius system
Calms the body down
‘ rest and digest ‘
Release acetylcholine
What is the function of the hypothalamus
- Found in middle part of brain
- Montains body temperature automaticcally
- Produces hormones that control the pituitary gland
What is the function of cerebrum
Involved in vision, hearing , learning and thinking
WHat is the function of pituitary gland
Conrolled by the hypothalamus
Releases hormones and stimulates other glands
eg , adrenal gland
What is the function of the medulla oblongata
Controls breathing rate and heart rate
What is the function by cerebellum
muscle coordination , posture and coordination of balance
Describe the blinking reflexes
Detect what can damage your eye
Sensory nerve endings stimulated by touch
Along sensory neurone to relay neurone in CNS
Along motor neurone to effectors
Eyes close quickly and precent eye being damaged
Describe the knee-jerk reflex
Maintain posture and balance
Stretch receptors in quadriceps muscle being stretched .
ALong sensory neurone, motor in spinal cord,
Motor neurone carries nerve to effector
Cause it to contract moves forwards.
How does the nervous and hormonal system coordinate fight or flight
Pituitary gland release a hormone called ACTH
Cause adrenal cortex release steroidal hormones.
Sympathetic activated , trigger release adrenaline from medulla
what effects does the sympathetic nervous system and adrenaline have
Heart rate increase - blood pumped around faster
Muscles around bronchioles relax - breathing is deeper
Glycogen converted into glucose - more glucose available for muscles to respire
Muscles in arterioles and skin and gut constrict . Muscles in arterioles supply heart , lungs to dilate - blood diverted from skin to heart and organs
Erector pili contract - make hair strands on animals bigger
How does the nervous system help to control the heart rate
SAN generates electrical impulses that cause the cardiac muscles to contract
Rate of SAN fires is controlled by medulla
Describe the structure of skeletal muscle
Made up of muscle fibres
Cell membrane is called the sarcolemma
Bits fold in an are called T-tubules to spread electrical impulses
Sarcoplasmic reticulum stores and releases calcium ions
Muscle fibres has many mitochondria to provide ATP
They are multinucleate
WHat do the myofybrils contain
Thick myofilaments Myosin
Thin myosin myofilaments Actin
Describe the crossection of the myofibril
A -BAnds = Thick myosin fil overlap thin actin fil
I bands - Onlu thin actin filaments
Z line - end of every sacromere
M line = middle of each sacromere / myosin filament
H zone = Contain only myosin filaments
Describe the structure of the myosin filaments
Have globular heads that are hinged to move back and forth
Has a binding site for actin and binding site for atp
Actin fil have binding site for myosin heads (actin-myosin binding sites)
topomyosin and toponin found between actin filaments.
Describe the binding sites in myosin filaments in resting muscles
Actin-myosin binding site is blocked by tropomysosin , held in place by troponin
SO myofilaments can’t slide past eachother
Describe how muscle contractions are triggered by a action potential
1) Action potential triggers influc of calcium ions
Depolarise sarcolema , spread to sarcoplasmic reticulum
Release calcium ions into ‘’
Calcium binds to troponin causing it to change shape , oulls attatches tropymosin out of binding site. Allow myosin head to bind , cause actin-myosin cross-bridge
2) ATP provides energy needed to move myosin head
Calcium ions activate ATPase , breaks down atp to provide enxyme
Pulls actin filament in a rowing action
**3) And to break cross bridge **
ATP provide energy to break crcoss bridge so myosin head detaches .
Myosin reattaches to a different binding site and cycle is repeated
Cycle will continue as long as calcium ions are bound to troponin
What happens when excitation stops
Calcium ion leave from toponin and moved by active transport into sarcoplasmic reticulum
Troponin return to origina; sjape , pull attached tropomyosin , block cinding site
How id ATP generated / made
Aerobic respiration
Generated by oxidative phosphorylation in mitochondria
Anaerobic respiration
made rapidly by glycolysis
End product is pyruvate so converted into lactate .
Quickly can build up and cause muscle fatigue
How is ATP - Creatine phosphate ( cp ) system mafe
ATP made by phosphorylating ADP - adding phosphate group from creatine phosphate
CP is stored inside cells and ATP-CO system generates ATP very quickly
What are neuromuscular junctions
Synapse between motor neurone and muscle cell.
Why does acetylcholine broken down after use in muscle cells
May brock the release of neurotransmitter / affect the way it binds to receptors .
May prvent the action potential from being past
So muscle won’t contract
Can be fatal if muscles affect involved in breathing
Describe skeletal muscles (voluntary muscles )
Controlled consciously
Many muscle fibres
Many nuclei
Cross striations
COntract very quick
Contract slowly and fatigue slowly
Describe involuntary muscle ( smooth muscle )
Contracts on its own - myogenic
Walls of heart
Fibres are branched to allow nerves to spread quickly
Contract slowly
dont fatigue
Describe cardiac muscle ( heart muscle)
Contracts on its own
Autono,ic nervous system
walls of heart
contract rhythmically and don’t fatigue
