CH12 Flashcards
5 Parts of brain
Cerebrum
- Controls mental, sensory and voluntary action
Cerebellum
- Coordinate movement & balance by coordinating smooth muscle and cardiac muscle
Hypothalamus
- regulate homeostasis
Pituitary glands
- secrete hormones that coordinate endocrine gland activities
Medulla oblongata
- controls involuntary and reflex action
5 Parts of a neuron
Dendrite
- receive impulse from other neurone
Axon
- Carry impulse out from cell body to another neurone
Myelin sheath
- Protect axons
- Provide nutrients to neurone
Node of ranvier
-Speed up impulse transmission as impulses hop from one ranvier node to another
Cell body
- Integrate nerve impulse
- Control neurone activity
Characteristics of each type of neurone
Sensory
- carry impulse from receptor or sensory organ to central nervous system
- located in the dorsal root of spinal cord
- short axons
- cell body is in the middle of axon
Motor
- carry impulse from relay neurone/central nervous system to effector (muscles or glands)
- located in the ventral root
- long axon
- cell body at the end of axon
Relay
- carry impulse from sensory neuron to motor neuron
-l located in central nervous system
- various shapes
Process of Transmission of impulse across synapse
When nerve impulse arrive at the sypnatic knob, vesicles containing neurotransmitter will move towards transmitting neuron
Vesicles membrane fuses with transmitter neurone and releases neurotransmitter into synapse
Neurotransmitter cross the synapse and fuses with specific protein receptor in the receiving neuron
New nerve impulse is triggered and move along the receiving neuron
Used neurotrasnmitter will be destroyed by enzymes and reabsorbed by sypnatic knob
Synapse only allow impulses to move in single direction :
- vesicles containing neurotransmitter is only found at presypnatic knob
- receptor bind with neurotransmitter only found at post synaptic knob
Reflex arc for knee jerk reflex
Stretch receptors in muscles are stimulated as…….
Nerve impulse are triggered and sent to spinal cord by sensory neuron
Nerve impulse are sent by motor neuron to the effector ( quadriceps muscle )
Quadriceps contract and leg jerks upward
Reflex arc for pulling of hand
Nociceptor in skin are stimulated when ….
Nerve impulse are triggered and sent to the spinal cord via sensory neuron
Sensory neuron transmit nerve impulse to relay neuron
Relay neuron send nerve impulse to motor neuron
Impulse is sent to the effector (biceps muscle) by motor neuron
Biceps muscle contract, arm is pulled away
8 Endocrine glands with hormone secreted
Hypothalamus
- GnRH: stimulate secretion of oestrogen and progesterone into the blood stream
Pituitary gland
- Growth hormone : control growth process
- Follicle stimulating hormone: stimulate ovary to secrete oestrogen, stimulate development of follicle in the ovary
- Luteinizing hormone : Stimulate ovulation, stimulate formation of corpus luteum in ovary, stimulate ovary to secrete progesterone
- Thyroid stimulating hormone : stimulate secretion of thyroxine by thyroid gland
- Adrenocorticotrophic hormone ACTH : control secretion of cortisol by adrenal gland
- Oxytocin : causes contraction in uterine walls during labour and stimulate production of milk in mammary glands
- Antidiuretic hormone : increases permeability of walls of collecting duct and distal convoluted tubule to water
Thyroid gland :
- Thyroxine : increase cell metabolism rate, allow normal physical growth and development
Pancreas :
- Insulin : convert glucose to glycogen
- Glucagon : convert glycogen into glucose
Adrenal gland :
- adrenaline : increase body metabolism rate, heart rate, blood circulation and stimulate conversion of glycogen into glucose
- aldosterone : increases permeability of wall of collecting duct and distal convoluted tubule to salts
