Biology module 5 section 3 - animal responses

CNS - Central nervous system

brain and spinal cord

peripheral nervous system

neurones that connect cns to the rest of the body, has 2 diff functional systems: somatic and autonomic nervous systems

somatic nervous system

controls the conscious activities

autonomic nervous system

controls the unconscious activities for example digestion and breathing. Split into sympathetic and parasympathetic nervous system.

Sympathetic nervous system

the fight or flight system, gets the body ready for action, sympathetic neurones release neurotransmitters called noradrenaline

Parasympathetic nervous system

rest and digest, calms the body down, parasympathetic neurones release neurotransmitters acetylcholine

cerebrum

largest part of the brain, divided into 2 halves: cerebral hemispheres, has a cerebral cortex, involved in vision, hearing and thinking

hypothalamus

beneath the middle part of the brain, maintains the body temperature, produces hormones

medulla oblongata

base of the brain, controls breathing and heart rate

cerebellum

underneath the cerebrum, has a cortex, involved in muscle coordination , posture and balance

pituitary gland

beneath the hypothalamus, controlled by it, releases hormones and stimulates other glands for example the adrenal gland to release hormones

ACTH

hormone released by the pituitary gland, causes cortex of the adrenal gland to release steroid hormones

Baroreceptors

Pressure receptor in the aorta and carotid arteries, stimulated by increases and decreases in blood pressure

Chemoreceptors

chemical receptors in the aorta, carotid arteries and medulla oblongata, monitor oxygen levels and carbon dioxide and pH level

Students t test

statistical test, is there a significant difference between 2 data sets

sarcolemma

call membrane of a muscle cell

sarcoplasm

muscle cells cytoplasm

transverse (T) tubules

Bits of sarcolemma that fold inwards towards the muscle fibres and stick into the sarcoplasm, they help spread the electrical impulses throughout th sarcoplasm so they reach all parts of the muscle fibres

sarcoplasmic reticulum

network of internal membranes that runs through the sarcoplasm which stores and releases calcium ions needed for contraction

myofibrils

long cylindrical organelles made up of proteins and highly specialised for contraction

myofilaments

are either thick myosin of thin actin proteins

sarcomeres

short units made up of myofibril, end in Z-line, middle is called M-line, which is surrounded by the H-zone which only contains the protein myosin

Sliding filament model

myosin and actin filament slide over one another to make sarcomeres contract

actin-myosin binding sites

binding sites for the myosin head s on actin filament

tropomyosin

protein found between actin filaments, attached to troponin, both help myofilaments move past each other, in resting state, tropomyosin blocks actin-myosin binding sites.

troponin

calcium ions bind to it and this changes the proteins shape, pulling the tropomyosin out of the actin-myosin site, allowing myosin head to bind

actin-myosin crossbridge

bond formed when myosin head binds to actin filament

skeletal muscle

voluntary muscle, long muscle fibres, cross-striations, multinucleate, fatigues

smooth muscle

involuntary, no striped appearance, in the walls of hollow internal organs, uninucleate, spindle-shaped and doesnt fatigue

Nicotinic cholinergic receptors

ACh binds to them on post-synaptic membrane

Acetylcholinesterase (AChE)

Stored in clefts in the post-synaptic membrane, breaks does ACh after it is used